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Unmanned Spaceflight.com _ Messenger _ MESSENGER News Thread

Posted by: paxdan Apr 20 2005, 11:22 AM

http://www.nasa.gov/centers/kennedy/news/releases/2004/59-04.html on August 3rd 2004, http://www.nasa.gov/mission_pages/messenger/main/index.html will become the first spacecraft to orbit http://en.wikipedia.org/wiki/Mercury_(planet).

News and updates are availbale via Johns Hopkins University MESSENGER http://messenger.jhuapl.edu/index.html and the Kennedy Space Center's MESSENGER http://www.ksc.nasa.gov/elvnew/messenger/index.htm.

There will be an earth flyby in August followed by a couple of swings by Venus and three velocity scrubbing passages past mecury before the craft enters orbit in March 2011.

April 18, 2005 http://messenger.jhuapl.edu/news_room/status_report_04_18_05.html from JHU. Extensive JHU FAQs page http://messenger.jhuapl.edu/faq/index.html.

Posted by: Buck Galaxy May 29 2005, 06:19 PM

QUOTE (paxdan @ Apr 20 2005, 11:22 AM)
http://www.nasa.gov/centers/kennedy/news/releases/2004/59-04.html on August 3rd 2004, http://www.nasa.gov/mission_pages/messenger/main/index.html will become the first spacecraft to orbit http://en.wikipedia.org/wiki/Mercury_(planet).

News and updates are availbale via Johns Hopkins University MESSENGER http://messenger.jhuapl.edu/index.html and the Kennedy Space Center's MESSENGER http://www.ksc.nasa.gov/elvnew/messenger/index.htm.

There will be an earth flyby in August followed by a couple of swings by Venus and three velocity scrubbing passages past mecury before the craft enters orbit in March 2011.

April 18, 2005 http://messenger.jhuapl.edu/news_room/status_report_04_18_05.html from JHU. Extensive JHU FAQs page http://messenger.jhuapl.edu/faq/index.html.
*





I for one can barely wait for Messenger. There is a big section of Mercury we've never seen, and I would love to also see close ups of the huge polar ice deposits.

Posted by: Jeff7 May 29 2005, 08:14 PM

QUOTE (Buck Galaxy @ May 29 2005, 02:19 PM)
QUOTE (paxdan @ Apr 20 2005, 11:22 AM)
http://www.nasa.gov/centers/kennedy/news/releases/2004/59-04.html on August 3rd 2004, http://www.nasa.gov/mission_pages/messenger/main/index.html will become the first spacecraft to orbit http://en.wikipedia.org/wiki/Mercury_(planet).

News and updates are availbale via Johns Hopkins University MESSENGER http://messenger.jhuapl.edu/index.html and the Kennedy Space Center's MESSENGER http://www.ksc.nasa.gov/elvnew/messenger/index.htm.

There will be an earth flyby in August followed by a couple of swings by Venus and three velocity scrubbing passages past mecury before the craft enters orbit in March 2011.

April 18, 2005 http://messenger.jhuapl.edu/news_room/status_report_04_18_05.html from JHU. Extensive JHU FAQs page http://messenger.jhuapl.edu/faq/index.html.
*





I for one can barely wait for Messenger. There is a big section of Mercury we've never seen, and I would love to also see close ups of the huge polar ice deposits.
*



"Big section" is putting it mildly.wink.gif If I recall correctly, one of the Mariner spacecraft was the only probe to go past Mercury, and it photographed only a little over a fourth of the planet.

Ugh, searching for Mercury Mariner on Google turns up more matches for some damn new SUV called just that. Of course, it is a hyrbid with mileage about equal to my car, so I guess I can't really complain. smile.gif


Why is it such a long time until Messenger gets to Mercury?

Oh, seems NASA anticipated this question. http://www.nasa.gov/missions/solarsystem/f_messgrav.html. Orbital insertion around something so small requires a slower speed than, say, something like Cassini.

Should definitely be an interesting mission though. That's a fascinating probe too - all the adaptations needed for flying so close to the sun.

Posted by: tedstryk May 29 2005, 08:33 PM

Mariner 10 Photographed 45% of Mercury, or almost half. But only basically one illumination condition was covered - due to orbital mechanics, the same side was illuminated on all three flybys. And the views of many areas were very forshortened on the limb.

Posted by: MiniTES May 29 2005, 09:51 PM

MESSENGER = strained acronym. It's even worse than Hipparcos.

Posted by: JRehling May 31 2005, 01:27 AM

QUOTE (Buck Galaxy @ May 29 2005, 11:19 AM)
I for one can barely wait for Messenger.  There is a big section of Mercury we've never seen, and I would love to also see close ups of the huge polar ice deposits.
*


As others noted, Mariner 10 imaged about 45% of the surface, not all well. Radar has provided some nice additional coverage, not all of which is available publicly.

But we're not going to see the polar ice deposits, at least not in visible wavelengths. They are, if they exist at all, in areas of permanent shade. It wouldn't take much sunlight at 0.4 AU to melt (vaporize) ice.

I suppose it's possible that a crater floor could be imaged in light reflected off of the crater wall, if imaging conditions are just right, and if that kind of lighting isn't enough to make any such parcel of ice disappear.

Posted by: tedstryk May 31 2005, 02:12 AM

QUOTE (JRehling @ May 31 2005, 01:27 AM)
As others noted, Mariner 10 imaged about 45% of the surface, not all well. Radar has provided some nice additional coverage, not all of which is available publicly.

  But we're not going to see the polar ice deposits, at least not in visible wavelengths. They are, if they exist at all, in areas of permanent shade. It wouldn't take much sunlight at 0.4 AU to melt (vaporize) ice.

  I suppose it's possible that a crater floor could be imaged in light reflected off of the crater wall, if imaging conditions are just right, and if that kind of lighting isn't enough to make any such parcel of ice disappear.
*



I doubt there is reflected light weak enough to not melt ice over eons and bright enough for Messenger to use it to create an image, especially with the glare from whatever is reflecting the light.

Posted by: edstrick May 31 2005, 05:02 AM

Uh... doesn't Messenger have a laser altimiter?... that measures reflectance, as well as delay-time which equals range...
I'd have to check, but I thought it did...

Posted by: Bob Shaw May 31 2005, 11:19 AM

I'm reminded of the darkside images taken of the Moon by Clementine - I wonder how well Venus will illuminate the shadowed parts of Mercury (obviously, at the right time of the Mercurian year it'll be *much* brighter).

Posted by: JRehling May 31 2005, 03:43 PM

QUOTE (Bob Shaw @ May 31 2005, 04:19 AM)
I'm reminded of the darkside images taken of the Moon by Clementine - I wonder how well Venus will illuminate the shadowed parts of Mercury (obviously, at the right time of the Mercurian year it'll be *much* brighter).
*


A full Venus has an absolute magnitude about 4 times that of the Earth, but is 130 times farther from Mercury than Earth is from the Moon. Venusshine onto Mercury should thus be about 1/4200 of the effect of earthshine on the Moon. Depending upon the specs of a camera, that could be used for some imaging, although I suspect that the Messenger camera would not be built for light-sensitivity the way, say, New Horizon's are. The kicker: if the polar areas never see the Sun due to the geometry, they'll never see Venus either.

Posted by: JRehling May 31 2005, 03:52 PM

QUOTE (edstrick @ May 30 2005, 10:02 PM)
Uh... doesn't Messenger have a laser altimiter?... that measures reflectance, as well as delay-time which equals range...
I'd have to check, but I thought it did...
*


Yes, the polar ice (if it exists as such) should be detectible through several instruments, and the laser altimeter is one possibility. If they are they, we will end up with image products, I'm sure, mapping them. But we won't have traditional imagery as such (I realize the distinction can be gray -- at what extent does a collection of reflectance data equal an image??).

I'll add that we don't have proof yet that the shadows of the polar craters hold full-fledged surface ice deposits -- only that the areas are highly reflective in radar. They may be dust-covered ice that appear as normal regolith in vis/IR. Whatever is going on there may possibly not involve water ice, but sulfur, for example. Verifying the suspected ice and determining whether or not any such ice is on the surface is something to find out. Finally, the same investigation will be happening with regard to the (presumably similar) phenomenon at the lunar poles. I guess LRO will shed light on the lunar version before Messenger gets to Mercury. (It's quite a coincidence that of the two large airless worlds in the inner solar system, both have large areas of permanent shadow near their poles! -- this wouldn't be true of the Earth or Mars.)

Posted by: Bob Shaw May 31 2005, 04:04 PM

Darn - I hadn't thought of that, and it's probably pretty obvious! Not only will libration effects be pretty minimal (unlike the Earth-Moon situation, where something interesting might be a goer), but as Venus and Mercury are probably in all sorts of orbital resonances there's likely to be only a few chances to view the same areas, badly illuminated at best. Oh, well, back to the drawing board.

OK, what about the Zodiacal Light...

Reflections from Comets...

Starlight...

Posted by: Chmee May 31 2005, 04:53 PM

QUOTE (Bob Shaw @ May 31 2005, 12:04 PM)
OK, what about the Zodiacal Light...

Reflections from Comets...

Starlight...
*


Or how about a high-yield fusion bomb detonated in orbit? Use it like a giant flash-bulb to take a picture! laugh.gif

You could even use the x-rays generated by the explosion to look for hydrogen.

Posted by: RNeuhaus Jun 1 2005, 02:48 AM

Is Mercury atmosphere similar to Moon rather than Mars? What are the composition of Mercury's atmosphere (helllium, hydrogen, oxigen, potassium and sodium)? Wiill the Messengare space answer these questions?

Posted by: paxdan Jun 1 2005, 08:39 AM

Earth from MESSENGER at 29.6 million km


Posted by: Sunspot Jun 1 2005, 08:40 AM

http://messenger.jhuapl.edu/news_room/press_release_5_31_05.html

"NASA’s Mercury-bound MESSENGER spacecraft – less than three months from an Earth flyby that will slingshot it toward the inner solar system – successfully tested its main camera by snapping distant approach shots of Earth and the Moon."

Posted by: um3k Jun 1 2005, 05:01 PM

No focusing problems on this baby! cool.gif

Posted by: lyford Jun 1 2005, 06:30 PM

I always enjoy these far off shots of Earth. They really drive home how BIG space is and how SMALL our home is...

Anybody seen a higher rez version?

Posted by: paxdan Jun 1 2005, 07:43 PM

QUOTE (lyford @ Jun 1 2005, 07:30 PM)
I always enjoy these far off shots of Earth.  They really drive home how BIG space is and how SMALL our home is...

Anybody seen a higher rez version?
*


i think this is the highest we are going to get without image processing.

from the article:

The image is cropped from the full MDIS image size of 1024x1024 pixels

Posted by: BruceMoomaw Jun 1 2005, 07:49 PM

QUOTE (RNeuhaus @ Jun 1 2005, 02:48 AM)
Is Mercury's atmosphere similar to Moon rather than Mars? What is the composition of Mercury's atmosphere (hellium, hydrogen, oxygen, potassium and sodium)? Wiill the Messenger spacecraft  answer these questions?
*


It will indeed provide a great deal of additional information on Mercury's atmosphere -- which is incredibly rarified and thus similar to the Moon's atmosphere rather than Mars'. Indeed, both worlds actually have what is described as an "exosphere" -- from which the atoms and molecules escape almost immediately -- rather thann any stable atmosphere. Its surface density is only about one trillion atoms per cubic centimeter. (I'd have to look this up -- I haven't been following the discoveries regarding Mercury's atmosphere closely -- but I think this is an atmospheric density roughly a trillionth of Earth's.)

We also have confirmed recently that Mercury's exosphere contains small amounts of calcium. The exosphere seems to come from atoms "sputtered" off Mercury's surface rocks by the impacting atoms of the solar wind -- a phenomenon much more intense on Mercury than on the Moon, thanks to its closer proximity to the Sun -- and it is suspected that Mercury's magnetic field focuses this activity so that much of the sputtering occurs near the planet's poles.

Messenger's "Mercury Atmospheric and Surface Composition Spectrometer" really consists of two separate, entirely different instruments that might as well count as two separate experiments; they have little to do with each other. Its near-infrared spectrometer will map surface mineral composition, while its ultraviolet spectrometer will specialize in measuring the density, distribution and composition of the exosphere. (I don't know whether it can measure calcium, but I suspect it can -- and one of its goals will be to try to identify additional elements in the atmosphere, such as magnesium, silicon and sulfur.) Messenger's "Energetic Particle and Plasma Spectrometer" also has some ability to directly detect different elements' ions by mass spectrometry -- again, I'd have to do some digging for the details.

Posted by: Bob Shaw Jun 2 2005, 09:00 PM

Bruce:

Can Messenger's instruments detect He on the surface of Mercury? I'm thinking of those old lunar He3 strip-mining plans...

Bob Shaw

Posted by: JRehling Jun 3 2005, 12:53 PM

QUOTE (Bob Shaw @ Jun 2 2005, 02:00 PM)
Bruce:

Can Messenger's instruments detect He on the surface of Mercury? I'm thinking of those old lunar He3 strip-mining plans...

Bob Shaw
*


In principle, He can be detected (quite easily, in fact), but that would only be if it existed in bulk concentrations, which it certainly will not. Lunar Prospector showed no He signal I'm aware of on the Moon. The quantity just isn't much to speak of.

Posted by: Buck Galaxy Jun 4 2005, 02:46 AM

QUOTE (JRehling @ Jun 3 2005, 12:53 PM)
In principle, He can be detected (quite easily, in fact), but that would only be if it existed in bulk concentrations, which it certainly will not. Lunar Prospector showed no He signal I'm aware of on the Moon. The quantity just isn't much to speak of.
*



Huh? I thought the moon's regolith was full of He3?

Posted by: Phil Stooke Jun 4 2005, 03:05 AM

Buck Galaxy said:

Huh? I thought the moon's regolith was full of He3?



No - it has minute amounts of He3. Major strip-mining would be needed to collect the amounts needed for the proposed power schemes.

Phil

Posted by: BruceMoomaw Jun 4 2005, 05:55 AM

Specifically, it's about one part He-3 per 100 million -- which gives you a better idea of the serious problems with mining the Moon for He-3 even if we finally do figure out how to fuse the stuff commercially (which we are absolutely nowhere near right now).

Posted by: Bob Shaw Jun 4 2005, 05:26 PM

Mining the moon for He3 would, of course, give us access to all sorts of other things in the process - not least being meteorites from Earth, Mars, Venus and so on. Possibly even fossils from a certain nearby life-bearing planet (our own!).

Posted by: Toma B Jun 15 2005, 04:41 PM

So there will not be another image of Earth for how long? huh.gif
Why don't they snap a picture at least once a week? blink.gif

Posted by: BruceMoomaw Jun 16 2005, 02:56 AM

Because Messenger is usually too close to Earth to see it as more than a speck -- only during its close flybys of Earth will its camera be able to see Earth clearly. (I believe there is only one more Earth flyby planned before it moves on to using repeated flybys first of Venus and then of Mercury itself to finally put itself into an orbit almost parallel to Mercury, thus allowing it to use an acceptably small amount of fuel to finally brake into orbit around Mercury itself. The Europa Orbiter -- when they finally fly it -- will, after it enters orbit around Jupiter, use repeated flybys of Callisto, Ganymede, and finally Europa itself to match orbits in a similar way with Europa before braking into orbit around Europa.)

Posted by: BruceMoomaw Jun 16 2005, 02:57 AM

"Because Messenger is usually too close to Earth to see it as more than a speck..."

Gaaah. I'm going senile. Make that "too FAR FROM Earth to see it as more than a speck".

Posted by: gpurcell Jun 16 2005, 03:34 PM

QUOTE (BruceMoomaw @ Jun 16 2005, 02:56 AM)
Because Messenger is usually too close to Earth to see it as more than a speck -- only during its close flybys of Earth will its camera be able to see Earth clearly.  (I believe there is only one more Earth flyby planned before it moves on to using repeated flybys first of Venus and then of Mercury itself to finally put itself into an orbit almost parallel to Mercury, thus allowing it to use an acceptably small amount of fuel to finally brake into orbit around Mercury itself.  The Europa Orbiter -- when they finally fly it -- will, after it enters orbit around Jupiter, use repeated flybys of Callisto, Ganymede, and finally Europa itself to match orbits in a similar way with Europa before braking into orbit around Europa.)
*


Bruce, do you know if they are planning to do science during the Venus encounters?

Posted by: BruceMoomaw Jun 17 2005, 06:54 AM

Yes indeedy. Quite a bit (even including using Messenger's laser altimeter to map Venusian cloud top altitudes). The question is whether it will do much of note that Venus Express won't (hopefully) already have done.

Posted by: JRehling Jun 28 2005, 12:05 PM

QUOTE (BruceMoomaw @ Jun 15 2005, 07:57 PM)
"Because Messenger is usually too close to Earth to see it as more than a speck..."

Gaaah.  I'm going senile.  Make that "too FAR FROM Earth to see it as more than a speck".
*


Usually, true, but it's getting closer all the time during these few months. The mission site now has animations depicting the Earth/Venus flybys, and I have some hope that Messenger could produce the "definitive" CCD images of Earth from space. There are darn few good CCD images of the full Earth, but Messenger will have an almost-full Earth for most of its approach, when Earth would fill and more than fill its camera frame. If they got some full-color shots at 6-hour intervals, it would be a wonderful thing, and an unusual photo credit for a Mercury-bound craft.

Posted by: djellison Jun 28 2005, 12:27 PM

Galileo and NEAR both did it - producing movies of the flybys by the time they'd finished

Doug

Posted by: Toma B Jun 28 2005, 01:37 PM

They did it....BUT WHERE ARE THE IMAGES OR MOVIES???
There are only few images...here and there.

Posted by: djellison Jun 28 2005, 01:50 PM

ERmmm..

NEAR - http://near.jhuapl.edu/Images/.Anim.html
specifically - http://near.jhuapl.edu/Voyage/img/earth_swby_lg.mpg


Galileo
http://galileo.jpl.nasa.gov/gallery/earthmoon-all.cfm


Took 60 seconds to find them

Doug

Posted by: Bjorn Jonsson Jun 28 2005, 03:24 PM

And if you want thousands of PDS-formatted Galileo images of the Earth there's always this:

http://pds-imaging.jpl.nasa.gov/cgi-bin/Nav/GLL_search.pl

Posted by: JRehling Jun 28 2005, 04:48 PM

QUOTE (djellison @ Jun 28 2005, 05:27 AM)
Galileo and NEAR both did it - producing movies of the flybys by the time they'd finished

Doug
*


The NEAR stuff is of a half-Earth and looks like it was compressed to the point of severe data loss. You can see lone pixels of red standing out with no other red around them. Maybe there's quality data there somewhere?

Galileo's images are nice, but suffer just a bit for being a very gibbous Earth and (like NEAR) highlighting Antarctica, which misses out on the egocentric "There I am!" potential, but also just looks atypical of any other land mass.

What I'm hoping is that Messenger produces a better product. Galileo's are not bad, but fall shy of canon-level (currently, that one overused Apollo image is about the only such image to have a full Earth and an inhabited continent).

Posted by: Sunspot Aug 2 2005, 07:45 PM

http://messenger.jhuapl.edu/news_room/press_release_8_02_05.html

NASA’s MESSENGER spacecraft, headed toward the first study of Mercury from orbit, swung by its home planet today for a gravity assist that propelled it deeper into the inner solar system.

Mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md, say MESSENGER’s systems performed flawlessly as the spacecraft swooped around Earth, coming to a closest approach point of about 1,458 miles (2,347 kilometers) over central Mongolia at 3:13 p.m. EDT. The spacecraft used the tug of Earth’s gravity to change its trajectory significantly, bringing its average orbit distance nearly 18 million miles closer to the Sun and sending it toward Venus for another gravity-assist flyby next year.

Posted by: dilo Aug 4 2005, 06:33 AM

waitng for the movie...
The picture reported in the Messenger site, taken with a telescope from Earth, show some darkening in the central part... look to this enhanced version:


Could be due to spacecraft re-orientation?

Posted by: Myran Aug 4 2005, 01:35 PM

Either reorientation or its in a constant slow rotation.

Posted by: djf Aug 28 2005, 02:19 AM

Just noticed this: http://planetary.org/news/2005/messenger_flyby_movie_0826.html

The movie of the rotating Earth receding in the distance is beautiful. It appears the dark, non-reflective area (i.e. dry land) going into darkness between 07:00-09:00UT is the north coast of Australia. Then near the end of the clip the deserts of the Arabian Peninsula and North Africa are visible through the clouds.

Posted by: deglr6328 Aug 28 2005, 02:54 AM

Oh that is just spec-freakin'-tacular! So smooth animation too! Wish there were a higer resolution version though.

Posted by: hendric Aug 28 2005, 01:48 PM

We do have one hell of a beautiful planet. smile.gif

Anyone know of rotation movies of other planets?

Posted by: JRehling Aug 28 2005, 04:14 PM

QUOTE (hendric @ Aug 28 2005, 06:48 AM)
We do have one hell of a beautiful planet. smile.gif

Anyone know of rotation movies of other planets?
*


No links here, but a quick list from memory:

Jupiter is probably the most prolific, with both Voyagers and Cassini having done movie-quality sequences. I think Cassini also did an approach sequence on Saturn, but it is not released yet. The data is out there for partial rotation sequences of Titan and Iapteus, but that will never be full from a single pass.

There's a nice partial rotation movie of Io in Jupiter's shadow.

Pioneer Venus has a few frames for Venus, but nothing movielike.

Posted by: tedstryk Aug 28 2005, 05:47 PM

QUOTE (JRehling @ Aug 28 2005, 04:14 PM)
No links here, but a quick list from memory:

Jupiter is probably the most prolific, with both Voyagers and Cassini having done movie-quality sequences. I think Cassini also did an approach sequence on Saturn, but it is not released yet. The data is out there for partial rotation sequences of Titan and Iapteus, but that will never be full from a single pass.

There's a nice partial rotation movie of Io in Jupiter's shadow.

Pioneer Venus has a few frames for Venus, but nothing movielike.
*


I imagine one could be made from the Mariner '67 Mars images.

Posted by: hendric Aug 28 2005, 08:59 PM

Hmmm...I wonder if they have done any ridiculously high resolution IMAX movies using full resolution shots of these rotations...

Posted by: djellison Aug 28 2005, 10:17 PM

If and when the Messenger data is on the PDS - I'll work it into a WMVHD movie if appropriate. I've been playing with MER imagery at 720p25 format, and it looks fab smile.gif


Doug

Posted by: Stephen Aug 29 2005, 01:42 AM

The MESSENGER team has posted a http://messenger.jhuapl.edu/the_mission/flyby_movie.html composed of 358 images they took during their craft's recent flyby showing the spinning Earth during one complete rotation disappearing into the void.

======
Stephen

Posted by: MizarKey Aug 31 2005, 10:00 PM

That movie is one of the most spectacular things I've ever witness...I love the sun's reflection off the ocean and land masses.

To loosely quote "Pale Blue Dot"..."Everyone who has ever lived or died, been written about...was right there" One fragile planet spinning in dark emptiness.

Eric P / MizarKey

Posted by: BruceMoomaw Aug 31 2005, 10:02 PM

It is; it's a lovely piece of work.

Posted by: dvandorn Sep 1 2005, 07:10 AM

That little movie captures the reality of what science fiction films have been speculatively presenting for more than a half a century.

Seeing the real thing at last, in such high definition realism, is immensely moving for me.

-the other Doug

Posted by: djellison Sep 1 2005, 07:24 AM

Correct me if I'm wrong - but Messenger's imager is a 1024 x 1024 instrument isnt it? - I wonder/hope if they captured that data at full res, or downsampled it to 512 x 512. If they DID do it full res, I promise - hand on heart - to make a full resolution version when the data is released.

Doug

Posted by: tedstryk Sep 11 2005, 12:36 PM

I was looking at the chart below. I noticed that beginning in October of next year, this mission should start getting interesting. Given the quality of the earth imagery, I am really excited about what we might see. I also wonder what if any science will be done at Venus.


Posted by: BruceMoomaw Sep 11 2005, 02:27 PM

Quite a bit -- they even intend to use the laser altimeter to measure Venusian cloud top altitudes.

Posted by: tedstryk Sep 11 2005, 05:43 PM

QUOTE (BruceMoomaw @ Sep 11 2005, 02:27 PM)
Quite a bit -- they even intend to use the laser altimeter to measure Venusian cloud top altitudes.
*


Thanks Bruce. My anticipation is building. Do you have any other information about Venus plans? I haven't seen much on how the Messenger instrument suit would be used.

Posted by: BruceMoomaw Sep 11 2005, 10:59 PM

Several years ago, Sean Solomon told me a fair amount about it -- but I'm not sure whether that's among the hundreds of stored E-mails that I later lost in an Outlook Express breakdown. I'll check when I get the chance. Suffice it to say that they plan to use virtually every Messenger instrument that CAN be used at Venus.

Posted by: um3k Sep 12 2005, 02:37 PM

QUOTE (BruceMoomaw @ Sep 11 2005, 06:59 PM)
Suffice it to say that they plan to use virtually every Messenger instrument that CAN be used at Venus.
*

Does that mean that we'll finally get some true (enough) color images of Venus? (really excited emoticon goes here!)

Posted by: JRehling Sep 12 2005, 06:21 PM

QUOTE (um3k @ Sep 12 2005, 07:37 AM)
Does that mean that we'll finally get some true (enough) color images of Venus? (really excited emoticon goes here!)
*


It's easy to get a true color picture of Venus -- take it from Earth! Getting that with excellent resolution and the fuller phases is another matter, but the true color of Venus isn't exactly an outstanding mystery. Note that the ability to align color channels in digital processing helps enormously with the chromatic edge effects that haunted film photography.

http://www.celestron-nexstar.de/referenzen/bilder/c14_venus_gudensberg.jpg

http://users3.ev1.net/~glennlray/Astro/Venus-20010203c.jpg

http://dvaa.org/Photos/TomBash/VenusPhasesC11.jpg

http://www.kk-system.co.jp/Alpo/kk04/v040511a.jpg

Posted by: um3k Sep 12 2005, 06:51 PM

I know you can get them from Earth, I meant pictures taken by a spacecraft. tongue.gif

Posted by: JRehling Sep 13 2005, 03:16 PM

QUOTE (um3k @ Sep 12 2005, 11:51 AM)
I know you can get them from Earth, I meant pictures taken by a spacecraft. tongue.gif
*


You can cover a box in foil and put a radio dish on it, place an amateur astronomer and a Celestron inside, and call it a spacecraft flying within 0.25 AU of Venus.

Posted by: The Messenger Sep 13 2005, 04:01 PM

The only problem with the timeline is that at orbital insertion, I will be as old and onry as Bruce biggrin.gif

Posted by: um3k Sep 13 2005, 04:36 PM

QUOTE (JRehling @ Sep 13 2005, 11:16 AM)
You can cover a box in foil and put a radio dish on it, place an amateur astronomer and a Celestron inside, and call it a spacecraft flying within 0.25 AU of Venus.
*

I mean a spacecraft...in space. Within a few thousand km of Venus (or however close Messenger is going to get).

Posted by: odave Sep 13 2005, 04:50 PM

From the http://messenger.jhuapl.edu/faq/faq_journey.html#4:

QUOTE
The Venus flybys provide important opportunities to calibrate MESSENGER’s instruments on the way to Mercury and make new scientific observations of Earth’s “sister planet.” The team plans to image the upper cloud layers at visible and near-infrared wavelengths for comparison with earlier spacecraft observations.


Since they're planning on imaging at visible wavelengths, and given the care they took to do that awesome movie from the Earth flyby, I'd assume we're going to see some kind of true color image releases...

Posted by: BruceMoomaw Sep 14 2005, 07:36 PM

"The only problem with the timeline is that at orbital insertion, I will be as old and ornery as Bruce."

No you won't. By then, I will be significantly older and much more ornery.

Posted by: dvandorn Sep 14 2005, 07:45 PM

You don't need to be old to be ornery (though it helps). I'd say the orneriest person I ever met was Harlan Ellison, back in the late '70s when he was a rather young man. He was ornerier then than most people get to be in their advanced years...

-the other Doug

Posted by: BruceMoomaw Sep 15 2005, 05:52 AM

Let me add to my reputation for orneriness: if you ever see him again, tell him to get off his damned duff and either publish "The Last Dangerous Visions" or at least release the stories he acquired for it from now-dead authors. The very last stories by Edgar Pangborn and Tom Reamy have now been moldering in a box in his office for three straight decades, and I wouldn't be surprised if there aren't a few more stories there by authors who have since gone to their reward.

Posted by: edstrick Sep 15 2005, 08:09 AM

Harlan Ellison: "The Mouth that Walks like a Man"

Being near Harlan is like the Ancient Chinese Curse: May You Live in Interesting Times.

Some of the LDV stories have been released and published, including a postumous collaboration between Cordwainer Smith and his wife, I believe.

Posted by: Bob Shaw Sep 15 2005, 08:48 PM

QUOTE (BruceMoomaw @ Sep 15 2005, 06:52 AM)
Let me add to my reputation for orneriness: if you ever seen him again, tell him to get off his damned duff and either publish "The Last Dangerous Visions" or at least release the stories he acquired for it from now-dead authors.  The very last stories by Edgar Pangborn and Tom Reamy have now been moldering in a box in his office for three straight decades, and I wouldn't be surprised if there aren't a few more stories there by authors who have since gone to their reward.
*


Bruce:

Yup. The arrogance of the horrible wee big-head, and his terrible attitude to TLDV's contributors (many of whom are now, as you rightly say, ex-contributors), are beyond belief.

Bob Shaw

Posted by: BruceMoomaw Nov 6 2005, 02:20 AM

As I noted in the "Future Venus Missions" thread below, we now have a very detailed description of the science measurements that Messenger will make during its second Venus flyby in June 2007. (It won't make any during its first one because it's near solar conjunction.)
http://www.lpi.usra.edu/vexag/Nov2005/MESSENGER_VEXAG.pdf

Projected arrival data at Mercury for Bepi Colombo, by the way, is now 2017.

Posted by: Rakhir Nov 14 2005, 11:27 AM

Messenger Status Report :
MESSENGER Team Prepares for December Deep Space Maneuver (DSM-1), when the craft’s large bipropellant thruster will be fired for the first time.

http://messenger.jhuapl.edu/news_room/status_report_11_11_05.html

Rakhir

Posted by: antoniseb Nov 30 2005, 01:48 PM

I saw that Messenger is currently closer to the Sun than Venus is. This is not unexpected, but I thought it was an interesting milestone.

Posted by: tedstryk Nov 30 2005, 03:19 PM

QUOTE (Rakhir @ Nov 14 2005, 11:27 AM)
Messenger Status Report :
MESSENGER Team Prepares for December Deep Space Maneuver (DSM-1), when the craft’s large bipropellant thruster will be fired for the first time.

http://messenger.jhuapl.edu/news_room/status_report_11_11_05.html

Rakhir
*


I am a bit surprised, since I don't think it will be during the communications blackout, that they aren't taking Magnetometer and Energetic Particle and Plasma Spectrometer data, since that wouldn't require a large amount of bandwith or maneuvering.

Posted by: BruceMoomaw Nov 30 2005, 03:23 PM

This is the very last component of Messenger that hasn't already been tried out. (Andy Dantzler said at the COMPLEX meeting that the craft has had a few software hiccups, but no hardware problems whatsoever so far.)

Posted by: tedstryk Nov 30 2005, 03:52 PM

QUOTE (BruceMoomaw @ Nov 30 2005, 03:23 PM)
This is the very last component of Messenger that hasn't already been tried out.  (Andy Dantzler said at the COMPLEX meeting that the craft has had a few software hiccups, but no hardware problems whatsoever so far.)
*


What is "this" referring to? The instruments I spoke of or some earlier post?

Posted by: JRehling Nov 30 2005, 04:37 PM

QUOTE (tedstryk @ Nov 30 2005, 07:52 AM)
What is "this" referring to?  The instruments I spoke of or some earlier post?
*


The main thruster is apparently "this". It will be fired for the first time in this manuever. If "this" tongue.gif works, then we can have high expectations of a successful mission.

For no particular timely reason, I will re-voice the angst that it is so long between launch and any interesting science (even a Venus flyby)... If the earlier launch window had been hit, the mission would have been accelerated by *years*. The launch window that was used seems to have been about the worst one possible in terms of cruise duration.

Posted by: tasp Nov 30 2005, 06:02 PM

QUOTE (JRehling @ Nov 30 2005, 10:37 AM)
The main thruster is apparently "this". It will be fired for the first time in this manuever. If "this"  tongue.gif  works, then we can have high expectations of a successful mission.

For no particular timely reason, I will re-voice the angst that it is so long between launch and any interesting science (even a Venus flyby)... If the earlier launch window had been hit, the mission would have been accelerated by *years*. The launch window that was used seems to have been about the worst one possible in terms of cruise duration.
*



Has anyone looked at return paths from Mercury to earth via Mercury, Venus and earth gravitational assists?

Posted by: JRehling Nov 30 2005, 07:53 PM

QUOTE (tasp @ Nov 30 2005, 10:02 AM)
Has anyone looked at return paths from Mercury to earth via Mercury, Venus and earth gravitational assists?
*


It should be roughly symmetrical. You can't make the planets reverse direction, but conceptually...

The big problem is that a trip to Mercury starts with a huge rocket on the surface of the Earth. Getting a big rocket to the surface of Mercury is going to be a problem. The requirement would be at least to reach Mercury escape velocity and then enter a minimum-energy transfer orbit from Mercury's aphelion to Venus. Some additional savings could be had by using Mercury flybys to pump the orbit out to Venus. The rocket capable of that operation has to be the *payload* of some other rocket. The demands are incredible, certainly beyond any unmanned mission ever flown.

There would be an energy savings if, like Apollo, a remote rendezvous took place, so that the return fuel for the interplanetary cruise did not have to be landed onto the surface of Mercury. This would help, but the demands would still be huge (a rocket that could perform the cruise would have to enter Mercury orbit no matter how you look at it).

Look, it's just not going to happen in our lifetime! wink.gif

Posted by: dvandorn Nov 30 2005, 10:41 PM

Well, it *may* not happen in the lifetimes of the average members of this forum. But that all depends on the state of advancement of propulsion technology. I've seen some articles on plasma drive concepts that are being championed by, among others, Franklin Chang-Diaz, that could dramatically increase the amount of delta-V capacity a spaceship can drag along with it.

If we can develop bigger, better propulsion systems in the next 20 or 30 years, things that can give you constant acceleration for most of your flight (and not at measely 1/100th G levels, either), then you can tool around the Solar System in months when you used to need to spend years. Months or years when you used to need decades.

It's not like we will *always* be limited to push-real-hard-then-coast-for-years technologies. At least, I'm sincerely hoping not.

-the other Doug

Posted by: tasp Dec 1 2005, 02:42 AM

I was hoping that since Messenger was launched on a mid size rocket, and that a large part of the delta vee is from the grav. assists at earth Venus, and Mercury, a big Titan IV (or whatever the big launcher is now) could send a useful vehicle on a two way trip. The 'smash and grab' idea for a sample return I saw here is just starting to seem a little more doable, perhaps . . . .

Amazing to be looking at these (formerly) exotic trajectories, from Mercury sample returns to Pluto landers, it just keeps getting better all the time.
biggrin.gif

Posted by: BruceMoomaw Dec 1 2005, 10:22 PM

Actually, it might be doable with a smaller booster. The question is how fast a flyby speed at Mercury you're willing to put up with during the sampling. Messenger will make multiple gravity-assist flybys of Mercury to slow itself down in order to minimize the fuel it has to burn at Mercury Orbit Insertion, but that problem doesn't apply to a nonstop smash-and-grab sampling flyby. The question is the speed at which the collected particles can plow through the aerogel before the frictional heat ruins them for scientific analysis.

But if you are willing to make that sampling run during your first flyby of Mercury, then making your way back to Earth via Venus gravity-asssist flybys becomes much easier and shorter.

Posted by: BruceMoomaw Dec 12 2005, 09:21 PM

http://www.space.com/astronotes/astronotes.html : Messenger fired its big engine successfully for almost 9 minutes on Dec. 12 -- the last component of the craft that hadn't been operated until then. So everything works (except for occasional software collywobbles). Now if everything will just continue working...

Posted by: ljk4-1 Dec 14 2005, 07:45 PM

A thought from someone on another space list:

Will MESSENGER and Venus Express conduct any joint studies on Venus like Galileo and Cassini did with Jupiter in 2000? And if they can and do, what could they do together that they could not do alone?

Posted by: AlexBlackwell Dec 14 2005, 08:28 PM

It might be possible during the June 2007 flyby; however, MESSENGER won't be collecting science data during the October 2006 flyby (due to solar conjunction), so that opportunity is out.

Posted by: AlexBlackwell Feb 23 2006, 05:35 PM

MESSENGER Mission News
February 23, 2006
http://messenger.jhuapl.edu/

--------------------------------------------------------------------------------

MESSENGER Lines Up for Venus Flyby

MESSENGER trajectory correction maneuver 10 (TCM 10) lasted just over two minutes and adjusted its velocity by about 1.4 meters per second (4.6 feet per second). The short-duration maneuver yesterday placed the spacecraft on track for its next major mission event: the first Venus flyby on October 24, 2006.

Having completed six successful small TCMs that utilized all 17 of the spacecraft’s thrusters, this latest maneuver was the first to rely on the four B-side thrusters. During this maneuver, the thrusters on the opposite side of the spacecraft reduced a build-up of angular momentum due to an unseen force that causes the spacecraft to rotate if left uncorrected. This maneuver was only the seventh actual TCM for MESSENGER; the spacecraft’s trajectory was so close to optimal after TCM 3 and TCM 6 that planned TCMs 4, 7 and 8 weren't necessary.)

The maneuver started at 11 a.m. EST; mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, verified the start of the maneuver within 11 minutes and 48 seconds, when the first signals indicating spacecraft thruster activity reached NASA's Deep Space Network tracking station outside Goldstone, Calif.

At the start of the maneuver, the spacecraft was 132 million miles (212 million kilometers) from Earth and 83 million miles (133 million kilometers) from the Sun, speeding around the Sun at 68,163 miles (109,698 kilometers) per hour.

For graphics of MESSENGER's orientation during the maneuver, visit the “Trajectory Correction Maneuvers” section at http://messenger.jhuapl.edu/the_mission/mission_design.html.


--------------------------------------------------------------------------------


Earth Flyby Image Gallery Now Online

MESSENGER’s Mercury Dual Imaging System (MDIS) acquired spectacular images during the Earth flyby in August 2005, including a "film" of our home planet as it receded in the distance. Now, you can browse through the best of the MDIS flyby frames on the MESSENGER Web site!

Visit the MDIS Earth Flyby gallery at http://cps.earth.northwestern.edu/MESSENGER_20050802/.

Posted by: dilo Mar 22 2006, 08:52 PM

Flyby images are beautiful, thanks Alex.
Starting from one eof these pictures and using also the famous MRO moon image, I made these mosaics... is only a "petit divertissment", first one should be geometrically more correct, while second one is a tribute... wink.gif


Posted by: angel1801 Mar 23 2006, 11:10 AM

QUOTE (AlexBlackwell @ Dec 15 2005, 05:58 AM) *
It might be possible during the June 2007 flyby; however, MESSENGER won't be collecting science data during the October 2006 flyby (due to solar conjunction), so that opportunity is out.


This is because Mercury transits the Sun on November 8 (19:14 UT) to November 9 (00:15 UT). And transits can only occur at inferior conjunction ie when Mercury anf Earth line up in a straight line anf Mercury is at "New moon" phase. Mercury is too close to the Earth for a month or so before and after the inferior conjunction for realiable transmission of data.

Posted by: AlexBlackwell Mar 23 2006, 04:48 PM

QUOTE (angel1801 @ Mar 23 2006, 11:10 AM) *
This is because Mercury transits the Sun on November 8 (19:14 UT) to November 9 (00:15 UT). And transits can only occur at inferior conjunction ie when Mercury anf Earth line up in a straight line anf Mercury is at "New moon" phase.

Thanks, angel1801. I think I remember something like that from an Astronomy 101 lecture but my memory is hazy because I was at a frat party the night before.

QUOTE (angel1801 @ Mar 23 2006, 11:10 AM) *
Mercury is too close to the Earth for a month or so before and after the inferior conjunction for realiable transmission of data.

Comm hiatus for solar conjunctions is a feature of many interplanetary missions. And I think you meant to write "Mercury is too close to the Sun..."

Posted by: ugordan Mar 23 2006, 05:06 PM

QUOTE (AlexBlackwell @ Mar 23 2006, 05:48 PM) *
Comm hiatus for solar conjunctions is a feature of many interplanetary missions. And I think you meant to write "Mercury is too close to the Sun..."

I'm lost. Isn't the next flyby that's not going to be taking any science a Venus flyby? If so, what's Mercury got with it?

I'm also a bit puzzled by this no-science policy. Why couldn't have they programmed the s/c to play the data back a couple of days/weeks later?

Posted by: Sunspot Mar 23 2006, 05:11 PM

QUOTE (ugordan @ Mar 23 2006, 05:06 PM) *
I'm also a bit puzzled by this no-science policy. Why couldn't have they programmed the s/c to play the data back a couple of days/weeks later?


That's what I was thinking too......

Posted by: AlexBlackwell Mar 23 2006, 05:16 PM

QUOTE (ugordan @ Mar 23 2006, 05:06 PM) *
I'm lost.

Take a number, ugordan. I was "lost" first. tongue.gif

QUOTE (ugordan @ Mar 23 2006, 05:06 PM) *
Isn't the next flyby that's not going to be taking any science a Venus flyby? If so, what's Mercury got with it?

Assuming angel1801 was referring to the upcoming Venus flyby, you're right, though rather than issuing two corrections, I gave him/her the benefit of the doubt and assumed he/she was making a general statement with respect to MESSENGER being in orbit around Mercury. That's my "Bruce excuse." In reality, I just wasn't paying too close attention. biggrin.gif

Posted by: dilo Mar 23 2006, 09:28 PM

A flyby mosaic (only 7 images)

 

Posted by: AlexBlackwell Mar 24 2006, 09:08 PM

http://messenger.jhuapl.edu/news_room/status_report_03_24_06.html
MESSENGER Status Report
March 24, 2006

Posted by: antoniseb Apr 5 2006, 08:20 PM

Messenger is now further from the Sun than the Earth is. It will stay that way for several weeks, and then never again will it be that far from the Sun.

Posted by: abalone Apr 6 2006, 01:20 PM

QUOTE (AlexBlackwell @ Mar 25 2006, 07:08 AM) *
http://messenger.jhuapl.edu/news_room/status_report_03_24_06.html
MESSENGER Status Report
March 24, 2006

What is this mile you speak of??

Sorry to be so petty but there is no place for imperial units in any endevour that promotes itself as being either scientific or international, NASA needs to get a grip!!

Posted by: RNeuhaus Jun 24 2006, 04:52 AM

A new update news from Messenger status:

Mercury Messenger Probe Flips Sunshade Towards The Sun

http://www.spacedaily.com/reports/Mercury_Messenger_Probe_Flips_Sunshade_Towards_The_Sun.html

The Messenger spacecraft performed its final "flip" maneuver for the mission on June 21. Responding to commands sent from the Messenger Mission Operations Center at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., through NASA's Deep Space Network antenna station near Goldstone, Calif., the spacecraft rotated 180 degrees, pointing its sunshade toward the Sun.

Rodolfo

Posted by: AlexBlackwell Jul 27 2006, 02:03 AM

If this has been mentioned already, pardon the repeat, but for those who do not have access to some of those hard-to-obtain journals, I just noticed the http://messenger.jhuapl.edu/the_mission/publications.html now has links to several of the references.

Posted by: AlexBlackwell Aug 3 2006, 09:27 PM

MESSENGER Mission News
August 3, 2006
http://messenger.jhuapl.edu/

________________________________________________________

Happy Anniversary, MESSENGER!

Today marks the second anniversary of MESSENGER’s launch. “It’s still more than four and a half years to Mercury Orbit Insertion in March 2011, and there are many milestones between now and then,” says Dr. Sean C. Solomon, of the Carnegie Institution of Washington, who leads the mission as principal investigator. “But it’s worth pausing for a few moments today to appreciate how far we’ve come.”

And just how far has the spacecraft traveled since its Aug. 3, 2004, launch from Cape Canaveral Air Force Station, Fla.? Slightly more than 1.275 astronomical units (1 AU is Earth’s distance from the Sun). MESSENGER’s computers have executed 180,271 commands since liftoff, a time interval that includes seven major trajectory correction maneuvers.

“It’s been a busy two years,” says MESSENGER Mission Operations Manager Mark Holdridge, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. “We’ve been by Earth and now we are headed for Venus, another major milestone in this mission.”

MESSENGER team members have been running tests all summer to make sure the spacecraft will operate as intended during the Venus flyby – the first of two swings past the clouded planet –scheduled for Oct. 24, 2006. There will be a 57-minute solar eclipse during that operation. So on Aug. 11, engineers will turn the spacecraft solar panels edge-on to the Sun and discharge the battery, much in the same manner that the power system will function during the Venus flyby, to verify that the system will respond appropriately.

Two weeks later, on Aug. 21, engineers will conduct a “star-poor” region test, pointing the spacecraft’s star tracker in a region of the sky that might be utilized during the Venus operations Holdridge says a similar test was conducted on July 26, “and we got a positive result from that test; the preliminary results look good.”

All in all, Holdridge says, all systems are functioning very well. “The spacecraft is very healthy, and the team is working hard to make this first flyby of Venus a success!”

For encounter details and graphics associated with the October maneuver, go online to http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html

________________________________________________________

MESSENGER Engineer Named AIAA Engineer of the Year

APL’s T. Adrian Hill, the fault protection and autonomy lead for MESSENGER, was recently named Engineer of the Year by the Baltimore chapter of the American Institute of Aeronautics and Astronautics (AIAA). Each year, local AIAA chapters present this award to a member who has made significant contributions to the field of engineering. For more information, go online to http://www.jhuapl.edu/newscenter/pressreleases/2006/060623b.asp.

________________________________________________________

Where is Mercury?
Mercury's orbit is so close to the Sun that we can only see it from Earth either just before sunrise or just after sunset. For a diagram of the orbits of the inner planets, as they appear today, go online to http://btc.montana.edu/messenger/wheremerc/wheresmerc.php.

________________________________________________________

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Posted by: AlexBlackwell Aug 4 2006, 09:23 PM

MESSENGER Mission News
August 4, 2006
http://messenger.jhuapl.edu/
______________________________________________________________________________

CORRECTION

The August 3, 2006, MESSENGER Mission News incorrectly stated that the spacecraft had traveled “slightly more than 1.275 astronomical units” since its August 3, 2004, launch from Cape Canaveral Air Station, Fla. In fact, since lift off MESSENGER has traveled nearly 1.2 billion miles in its orbit around the Sun.

The spacecraft is currently 1.285 astronomical units (AU) distant from the Earth (1 AU equals 93 million miles). To track MESSENGER’s journey, go online to http://messenger.jhuapl.edu/whereis/index.php.

_______________________________________________________________________________

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Posted by: AlexBlackwell Sep 16 2006, 12:36 AM

http://messenger.jhuapl.edu/news_room/status_report_09_15_06.html
MESSENGER Mission News
September 15, 2006

Posted by: climber Oct 10 2006, 09:16 PM

A quick reminder : Messenger is only 13 days to Venus flyby.
http://messenger.jhuapl.edu/

Posted by: mchan Oct 11 2006, 03:51 AM

Noteworthy. Too bad there will not be science observations on this flyby due to conjunction.

Posted by: odave Oct 11 2006, 12:41 PM

IIRC the trajectory of this flyby wasn't very interesting for science returns anyway. Though maybe they could try to image that http://www.unmannedspaceflight.com/index.php?s=&showtopic=3232&view=findpost&p=69368 wink.gif

Posted by: ugordan Oct 11 2006, 01:27 PM

This view hardly qualifies as uninteresting: http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=299&vbody=-236&month=10&day=24&year=2006&hour=07&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1

Posted by: odave Oct 11 2006, 01:36 PM

Hmmm. I'll have to find out where I read what I read... unsure.gif

Posted by: ugordan Oct 11 2006, 01:40 PM

From what I've seen playing around in the Simulator the past few minutes, it's a very low phase inbound and very high phase outbound encounter. Maybe not very photogenic for global imaging as you'd prefer moderate phase angles (at least I do), but in terms of cloud observation tracking and similar stuff it could have been pretty nice.

Posted by: odave Oct 11 2006, 02:01 PM

That rings a bell, but I haven't been able to Google up anything to support what I recalled. Chalk it up to my http://www.unmannedspaceflight.com/index.php?s=&showtopic=1705&view=findpost&p=46514 syndrome... tongue.gif

Posted by: Jeff7 Oct 11 2006, 02:11 PM

QUOTE (climber @ Oct 10 2006, 05:16 PM) *
A quick reminder : Messenger is only 13 days to Venus flyby.
http://messenger.jhuapl.edu/

Ah good, it can act as Venus Express Express. biggrin.gif

Posted by: dvandorn Oct 11 2006, 04:56 PM

QUOTE (odave @ Oct 11 2006, 09:01 AM) *
Chalk it up to my http://www.unmannedspaceflight.com/index.php?s=&showtopic=1705&view=findpost&p=46514 syndrome... tongue.gif

That's OK, Dave -- just wait until it progresses, as it has with me, to the more advanced form, CRAFT... huh.gif

-the other Doug

edit -- see, goes to show you, you were referencing a post of mine, and I totally had no memory of it... toD

Posted by: tuvas Oct 19 2006, 04:31 AM

QUOTE (Jeff7 @ Oct 11 2006, 07:11 AM) *
Ah good, it can act as Venus Express Express. biggrin.gif


Too bad it won't have much of a chance to do any photographing, but it's a good idea...

Posted by: RNeuhaus Oct 19 2006, 03:24 PM

QUOTE (tuvas @ Oct 18 2006, 11:31 PM) *
Too bad it won't have much of a chance to do any photographing, but it's a good idea...

Yes, Messenger's will fly-by on Venus on the day and night side of Venus and besides, now, Venus is close to conjunction superior to Earth along with Mars.

You can find good details by visiting the following Web Page http://http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html

Minimum altitude (approximate since the surface is not perfectly round) above Venus: 3,040.1 kilometers (1,889.0 miles) on October 24, 2006 8:33 am UTC

Maximum spacecraft speed relative to center of Venus:
12.378 kilometers per second (7.691 miles per second or 27,689 miles per hour)

Rodolfo

Posted by: helvick Oct 19 2006, 04:18 PM

You have a typo in the URL there - it should be:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html

Posted by: BPCooper Oct 19 2006, 11:33 PM

QUOTE (helvick @ Oct 19 2006, 12:18 PM) *
You have a typo in the URL there - it should be:
http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/VenusFlyby1.html


Are the animations mislabeled, or are they from the original flyby dates for Mercury arrival in 2009? They both say Nov. 2 2004 and were updated last year, post launch.

Posted by: RNeuhaus Oct 20 2006, 02:08 AM

QUOTE (BPCooper @ Oct 19 2006, 06:33 PM) *
Are the animations mislabeled, or are they from the original flyby dates for Mercury arrival in 2009? They both say Nov. 2 2004 and were updated last year, post launch.

Why not? The animations is of First Venus Flyby, then again Venus Flyby on June 6,2007, and finally two Mercury flyby (Jan 14,2008 and October 6, 2008) and March 18, 2011 is the Mercury arrival.

Rodolfo

Posted by: Holder of the Two Leashes Oct 20 2006, 02:51 PM

Don't forget the animation for the third Mercury flyby on 30 Sep 2009.

The top right panel on the link for the first Venus flyby clearly states, when you enlarge it, that the spacecraft will be out of communication with earth due to the proximity of the sun in the line of sight.

Things will be better on the second flyby, and you'd think that they should be able to come up with some kind of coordinated activity with Venus Express. After all, two capable spacecraft observing the same object from different vantage points ...

Posted by: JRehling Oct 20 2006, 05:51 PM

QUOTE (RNeuhaus @ Oct 19 2006, 08:24 AM) *
Yes, Messenger's will fly-by on Venus on the day and night side of Venus and besides, now, Venus is close to conjunction superior to Earth along with Mars.


Actually, they are both close to opposition. Mars will be in superior conjunction next year, and Venus is never in superior conjunction. wink.gif

Posted by: Holder of the Two Leashes Oct 21 2006, 04:12 AM

Mercury and Venus are in inferior conjunction when they are more or less between the earth and sun. They are in superior conjuction (as Venus is now) when they are pretty much behind the sun as seen from earth. Mars is simply in "conjunction" in this situation, because its conjuctions can only be superior. Mars and other outer planets are in opposition when they transit near midnight, being more or less overhead then.

Posted by: RNeuhaus Oct 23 2006, 03:28 AM

Tomorrow between 4-5 am, Messenger will be flying-by over Venus. I am still unclear about the Messenger path after seeing the flyby movies and pictures of Venus 1st Flyby. The pictures show that Messenger is coming from South Pole at about an angle of 60 degree to equotorial line. See the following picture:



The Meessenger approach to Venus side by side and it does not coincide with the above picture which shows that Messenger approach in about 85 degrees from the Sun to Venus.

http://messenger.jhuapl.edu/the_mission/movies.html
According to the picture which shows Earth, Venus and Mercury orbit around the Sun from the top view.

I am still puzzled that Messenger will approach to Venus from Sun and not by side by side toward with the same orbit direction as Venus.

Rodolfo

Posted by: Holder of the Two Leashes Oct 23 2006, 04:04 AM

Well, the two diagrams do match up. The tick marks are a little more compressed looking in from the sun, but if you carefully trace by the intervals, you'll see in both cases that as viewed from Venus the spacecraft moves in from the sun moving westward and northward, before being flung back south. It still continues west on its departure.

It's necessary to pursue this path, flung backwards from the normal counterclockwise motion of the planets as viewed from north, in order to lose energy relative to the sun, and adjust the orbit inward toward Mercury. It is also necessary to go to high latitudes on Venus in order to adjust to the plane of Mercury's orbit.

Posted by: yaohua2000 Oct 23 2006, 02:21 PM

2006-10-23 02:21:05 UTC — 1000000 km
2006-10-23 05:24:28 UTC — 900000 km
2006-10-23 08:27:49 UTC — 800000 km
2006-10-23 11:31:05 UTC — 700000 km
2006-10-23 14:34:15 UTC — 600000 km
2006-10-23 17:37:14 UTC — 500000 km
2006-10-23 20:39:59 UTC — 400000 km
2006-10-23 23:42:21 UTC — 300000 km
2006-10-24 02:44:00 UTC — 200000 km
2006-10-24 05:44:07 UTC — 100000 km
2006-10-24 06:01:58 UTC — 90000 km
2006-10-24 06:19:46 UTC — 80000 km
2006-10-24 06:37:31 UTC — 70000 km
2006-10-24 06:55:12 UTC — 60000 km
2006-10-24 07:12:50 UTC — 50000 km
2006-10-24 07:30:24 UTC — 40000 km
2006-10-24 07:47:58 UTC — 30000 km
2006-10-24 08:05:50 UTC — 20000 km
2006-10-24 08:27:26 UTC — 10000 km
2006-10-24 08:34:00 UTC — 9044 km (2992 km above surface)

Note: geometric range, not corrected for light-time

Posted by: RNeuhaus Oct 23 2006, 03:04 PM

QUOTE (Holder of the Two Leashes @ Oct 22 2006, 11:04 PM) *
Well, the two diagrams do match up. The tick marks are a little more compressed looking in from the sun, but if you carefully trace by the intervals, you'll see in both cases that as viewed from Venus the spacecraft moves in from the sun moving westward and northward, before being flung back south. It still continues west on its departure.

It's necessary to pursue this path, flung backwards from the normal counterclockwise motion of the planets as viewed from north, in order to lose energy relative to the sun, and adjust the orbit inward toward Mercury. It is also necessary to go to high latitudes on Venus in order to adjust to the plane of Mercury's orbit.

Good comments, I think a three dimensional graphic would help to view better. Also the above graphic is too small that I seems that after flyby Venus, Messenger would go away from the Venus toward Earth orbit. But, If there is a bigger (smaller scale) in a three dimensional, I would be able to see that after Venus fly-by, Messenger would go toward the South of Venus and little by little going toward on the counterclockwise. For the second fly-by in the June 6, 2007, Messenger will arrive at Venus comming from the North of Venus to South but on the opposite to Venus orbit direction? I see it is for slowing the speed as much as possible with the Venus gravitational pulling (from 13,500 km/sec at Venus 2 fly-by to 7,100 km/sec at Mercury 1 fly-by). But, when Messenger arrives at Mercury, it will be again flying the orbit around the Sun on the counterclockwise.

Rodolfo

Posted by: Holder of the Two Leashes Oct 24 2006, 12:40 AM

Yes, the emphasis on the second flyby would seem to be more toward reducing speed relative to the sun. The spacecraft will always be seen from the sun as moving eastward, giving a counterclockwise orbit as viewed from north to south. But Venus flinging it back will significantly reduce the spacecraft speed as seen from the sun (and microscopically increase the speed of Venus).

On the website space.jpl.nasa.gov you can see the approach (and departure) of Messenger in a broader scene up to a point. That point is 3:40 UTC on the 24th, with a sudden shift to a Venus centered approach line rather than sun centered for both planet and spacecraft. It will only show one snapshot at a given time at five minute intervals, but repeated entries will show the two closing in on each other.

Chose "MESSENGER" as seen from "above" with a selection of "60 degrees" field of view (make sure the field of view option is clicked) on this website and you'll see what I'm talking about.

Just about nine hours to go ...

Posted by: RNeuhaus Oct 24 2006, 02:41 PM

By now, I haven't found any internet refresh news. Let suppose that the flyby have occured today at around 4:30 am at EDT time.
How was the Venus 1 fly-by?

Rodolfo

Posted by: djellison Oct 24 2006, 02:44 PM

How could we possibly know? Venus, like Mars, is in conjunction. That is the reason there was no science planned for Messenger during this flyby - the spacecraft is totally out of touch.

Doug

Posted by: maycm Oct 24 2006, 03:09 PM

Why no science?

Surely Messanger could be programmed for observations well in advance for the flyby - even if it was unable to transmit the results until sometime aftwards?

Would this not be at least an opportunity to test run some of the instruments ahead of the eventual rendezvous with Mercury?

Posted by: djellison Oct 24 2006, 03:20 PM

There will be further chances to test the instruments out - but one could ask the same question of MGS, ODY and MRO at Mars during conjunction....why no science.

#1 reason - while you're out of touch you want the spacecraft to be as quiet as possible, so minimising the chance of anything going wrong and causing a safe event which may consume prop etc.

doug

Posted by: Phil Stooke Oct 24 2006, 03:20 PM

Why no science?

The question has been asked many times. Simply put, if you can't communicate with the spacecraft and the encounter is not the main focus of the mission, you can't afford to conduct complex operations. If anything goes wrong and the spacecraft enters safe mode you can't go to work on it, and the potential for fatal errors is too high. And... there's a second chance to do some Venus science later.

Phil

Posted by: RNeuhaus Oct 24 2006, 04:49 PM

QUOTE (Phil Stooke @ Oct 24 2006, 10:20 AM) *
Why no science?
And... there's a second chance to do some Venus science later.

Yes, at June 6, 2007 Messenger will have coordinations with VEX to conduct many science observations. It is a matter of time. This second flyby is a very important since Messenger will jump from Venusian orbit into to Mercurian orbit.

Rodolfo

Posted by: Sunspot Oct 24 2006, 05:23 PM

But MRO IS making daily observations during the conjunction period.

Posted by: djellison Oct 24 2006, 06:37 PM

Only a very limited ammount with two instruments in a steady orbit. To sequence fly-by observations is a much mroe involved and intensive operation. If Messenger does some Mag observations during this flyby, then that would be analogous to the MARCI/MCS obs of MRO during conjunction.

Doug

Posted by: djellison Oct 24 2006, 10:04 PM

Bloody hell :
MESSENGER swung by Venus at 8:34 UTC (4:34 a.m. EDT), according to mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. About 18 minutes after the approach, an anticipated solar eclipse cut off communication between Earth and the spacecraft. Contact was reestablished at 14:15 UTC (10:15 a.m. EDT) through NASA's Deep Space Network, and the team is collecting data to assess MESSENGER's performance during the flyby.

Posted by: nprev Oct 25 2006, 04:24 AM

smile.gif ...Doug, I assume "bloody hell" means "HELL yeah!" in American slang...I hope this is good news, although it seems a bit guarded... unsure.gif

Posted by: Bubbinski Oct 25 2006, 06:08 AM

I just saw something in the Florida Today "Flame Trench" blog that Messenger had an unexpected computer reset. I hope it's nothing serious.

Posted by: mchan Oct 25 2006, 06:13 AM

Bloody hell! And that is NOT HELL yeah!

Posted by: ugordan Oct 25 2006, 07:08 AM

Update on the flyby: http://messenger.jhuapl.edu/news_room/status_report_10_24_06.html.

There's also an http://messenger.jhuapl.edu/the_mission/pictures/approach_venus.html of Venus taken by MDIS from 16.5 million km.

Posted by: nprev Oct 27 2006, 01:26 AM

Rog on the "BH", Doug & Mchan...just didn't see any reference to the anomaly in Doug's post, so I got confused.

In fact, I can't find any mention of this on Google News or on the Messenger website, which is kind of worrisome. I hope this doesn't mean that anomaly recovery has been interrupted by superior conjunction. Anybody have an update?

Posted by: ugordan Oct 30 2006, 07:15 PM

There's something weird with the http://messenger.jhuapl.edu/whereis/index.php#view_earth page. Here are two screenshots of the same simulated time:



Notice how Earth's position shifts from right of the Sun to its left in the second image. Even taking into account the second image appears slightly rotated CCW w/respect to the first, it still doesn't look fit. Earth appears at two different positions at once. A bug?

Posted by: remcook Oct 30 2006, 07:40 PM

Seems OK to me. Looks just like parallax when you move towards mercury in the centre of your view.

Posted by: ugordan Oct 30 2006, 08:06 PM

How can you have parallax if your viewpoint (MESSENGER) is fixed?

Posted by: remcook Oct 30 2006, 09:56 PM

hold a pencil in front of you and turn your head.

Posted by: ugordan Oct 30 2006, 09:57 PM

You do realize that by turning your head, you're shifting your eyes, do you? MESSENGER is a single, fixed point in the simulation. Only the look vector changes.

Posted by: remcook Nov 1 2006, 11:52 AM

yes, but I think it's probably a very similar effect that comes out of the simulations. Not sure though, but it looks like it. Angles stay the same, but the projection doesn't, because you look in a different direction, so your plane of projection has a different angle. Will try to make a drawing.

Posted by: remcook Nov 1 2006, 12:07 PM

Here's the drawing. green and red show two objects at different distances. lines show middle and edges of field-of-view. If you have a projection plane perpendicular to the middle line at a distance c, a will not equal b for the two cases. Not sure this is how exactly they made the plot though.

 

Posted by: ugordan Nov 1 2006, 04:06 PM

I'm not sure I get that plot, but I understand what you're saying about the distances. However, I'm talking about the angle between Earth-Sun-Mercury, see how it changes in the two instances. That does look like a bug. I have a fair amount of experience playing around in Celestia/Orbiter and never have I encountered such position shifts, even for large FOVs. To drive my point further, here are two plots from the Solar System Simulator:
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=399&vbody=-236&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1

If you disregard the rotation (the sim probably aligns to the target north axis), you can see how the angle stays the same and is consistent with the first screenshot I posted, viewing Earth. Earth stays on the same "side" of the Sun in both cases, as one would expect.

Posted by: Bjorn Jonsson Nov 1 2006, 05:17 PM

Having a fairly extensive experience playing around with 3D software and even writing a 3D renderer myself I cannot see how this could be anything but a bug. The views are supposed to show the Earth and Mercury as seen from Messenger at the same time and therefore the same location. The field of view is identical (or at least very nearly so), judging from Mercury's distance in pixels from the Sun. However, not only is the Earth's location relative to the Sun different in the two images, its 'distance' is also different and that difference is big. The field of view also isn't very wide (~30°) so distortion isn't significant.

Assuming the views generated by the http://space.jpl.nasa.gov/ are correct the view showing the Earth from Messenger is correct (or very nearly so) while the one showing Mercury is not.

Posted by: remcook Nov 1 2006, 06:01 PM

ah, I think I know what you mean now. sorry, I misunderstood you - I looked at the sun and Mercury, not the angles between them all.

edit - what I think I was trying to say is that if you have a flat projection plane you might get things distorted, whereas you have a spherical projection plane the angles would always stay correct. I guess the same problems occur with e.g. a fisheye projection. angles of things relative to eachother may change depending on where you aim it. But if the fov is not very wide...

Posted by: Malmer Nov 1 2006, 08:32 PM

it has to be a bug.

There is no way that any projection can move objects around in respect to each other that way.

it looks to me as if these pictures are rendered with an equirectangular projection (ordinary 3d camera) and that the position of the camera has changed. Im 99.9% sure.

they probably have some strange offset. (like if you move out from an object in celestia and then turn the camera to look at something else)

The simulations look s bit substandard to me... not like something that you would expect from a project that cost millions and millions of dollars.

Posted by: remcook Nov 2 2006, 08:42 AM

Had another think I see now I was just being plain stupid smile.gif In my mind I had my projection plane some distance from the rotation point (Messenger), which would obviously give you a parallax. But maybe the programmer was similarly stupid smile.gif Man, sometimes I wonder why i get up in the morning sad.gif

Posted by: Phil Stooke Nov 3 2006, 02:37 AM

On the date in question the spacecraft and Venus were some little distance apart. It looks to me like one simulation was viewed from Venus and one from Messenger, just a simple mistake in entering the viewpoint before doing the rendering.

Phil

Posted by: ugordan Nov 3 2006, 08:26 AM

Nope. Not even Venus as viewpoint brings Earth to the other side of the Sun. http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=399&vbody=299&month=10&day=30&year=2006&hour=16&minute=00&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1.

Posted by: ugordan Dec 13 2006, 04:22 PM

MESSENGER Mission News
December 2, 2006

http://messenger.jhuapl.edu/news_room/status_report_12_02_06.html

Posted by: Littlebit Dec 13 2006, 04:44 PM

QUOTE (ugordan @ Dec 13 2006, 09:22 AM) *
MESSENGER Mission News
December 2, 2006

http://messenger.jhuapl.edu/news_room/status_report_12_02_06.html

Interesting. The Venus post fly-by correction was originally scheduled for December 12. I wonder why they moved it up to December 2?

Posted by: tasp Dec 13 2006, 06:06 PM

IIRC, a similar change was made to the Voyager 1 (or was it 2?) flight plan post Jupiter.

It wound up saving some fuel as they were able to correct for some slight error sooner than had they waited for the error to have longer to operate.

Posted by: Greg Hullender Jan 23 2007, 11:38 PM

I see Messenger has just started its fourth orbit. (Yes, I know it's a silly milsetone, but I like the graphs.)

http://messenger.jhuapl.edu/whereis/index.php#current_orbit

Given the shape of the orbit, that gravitational assist from Venus in June is going to be a whopper. I note also that we're within one year of the first Mercury flyby.

Posted by: NMRguy Jan 31 2007, 03:21 PM

QUOTE (Greg Hullender @ Jan 24 2007, 12:38 AM) *
I note also that we're within one year of the first Mercury flyby.


That’s a mission fact that isn’t so apparent from the MESSENGER website front page. Sure, we still have over 1500 days before orbit insertion, but the Venus flyby/gravity assist in early June sends the craft careening towards Mercury with the first flyby occurring on January 14, 2008. About half of the hemisphere facing the sun is unexplored, and MESSENGER should get great views of it on the outbound.

http://messenger.jhuapl.edu/the_mission/ani.html

Posted by: Greg Hullender Feb 4 2007, 08:14 PM

I was looking at the Messenger site, trying to figure out how many times Messenger will orbit Mercury before the first flyby, and I ended up constructing this table, which I thought I'd share:

Event SMA Period Orbits Date Total Orbits

Launch 1 365 1.00 8/3/2004
E1 0.809 266 1.69 8/2/2005 1.00
V1 0.724 225 1.00 10/24/2006 2.68
V2 0.539 145 1.55 6/5/2007 3.68
M1 0.507 132 2.01 1/14/2008 5.23
M2 0.466 116 3.09 10/5/2008 7.24
M3 0.435 105 5.10 9/29/2009 10.33
MOI 0.388 88 3/18/2011 15.43

(Hope that comes out looking right, given the tabs.)

First column is all the milestones in the mission. Second column is the semi-major axis of Messenger's orbit (in AU) AFTER each event. Third column is the period (in days) of that orbit. Fourth column is the number of orbits it makes before the next event. Fifth column is the date of each event. Last column is the total number of orbits before each event. (All these figures, except the orbit counts, come directly from the Messenger website.)

So, from this, I can see that Messenger will reach Mercury's orbit for the first time 145 days before the flyby -- on or around August 23 of this year.

That's a kind of cool milestone, I think. (Assuming I haven't messed up the figures somehow.)

--Greg

Posted by: AlexBlackwell Feb 5 2007, 08:15 PM

http://messenger.jhuapl.edu/news_room/status_report_02_05_07.html
MESSENGER Mission News
February 5, 2007

Posted by: JRehling Feb 7 2007, 07:21 PM

QUOTE (NMRguy @ Jan 31 2007, 07:21 AM) *
That’s a mission fact that isn’t so apparent from the MESSENGER website front page. Sure, we still have over 1500 days before orbit insertion, but the Venus flyby/gravity assist in early June sends the craft careening towards Mercury with the first flyby occurring on January 14, 2008. About half of the hemisphere facing the sun is unexplored, and MESSENGER should get great views of it on the outbound.

http://messenger.jhuapl.edu/the_mission/ani.html


While the first two flybys alone theoretically expose almost all of Mercury's surface to Messenger's cameras, a lot of the antiMariner terrain will be near the limb during the second and third flybys. The first one will indeed represent a lot of filling in the map that Mariner 10 began. By the time the main mission begins, we will have a decent global map of the planet, but with some areas covered only in low resolution. After 32 years of waiting, though, 11 months for a big chunk of new coverage seems like almost nothing.

Posted by: AlexBlackwell Feb 20 2007, 04:27 PM

http://messenger.jhuapl.edu/news_room/status_report_02_20_07.html
MESSENGER Mission News
February 20, 2007

Posted by: NMRguy Mar 19 2007, 04:25 PM

http://messenger.jhuapl.edu/news_room/status_report_03_19_07.html
MESSENGER Mission News
March 19, 2007

A new mission update. MESSENGER's Energetic Particle and Plasma Spectrometer (EPPS) has been fired back up, and both components are working nominally. Also, the team notes that yesterday (March 18) it was 4 years to the day for Mercury insertion.

Posted by: NMRguy Apr 2 2007, 08:36 PM

http://messenger.jhuapl.edu/news_room/status_report_04_02_07.html
MESSENGER Mission News
April 2, 2007

Two-Fifths of the cruise duration is now behind us. A somewhat arbitrary landmark (spacemark?), but the MESSENGER team uses this as an opportunity to let us know what they are planning in June. Perhaps we'll get a nice combined NASA/ESA press release after the flyby? Time will tell.


"Planning is now underway to use the second Venus flyby on June 5 to complete final rehearsals for three Mercury flybys. Those flybys, assisted by four deep space maneuvers, will slow the spacecraft sufficiently for Mercury orbit injection on March 18, 2011.

The upcoming planetary encounter also offers a variety of opportunities for making new observations of Venus’ atmosphere and cloud structure, space environment, and, perhaps even the surface. All of the MESSENGER instruments will be trained on Venus during the encounter.

* The MDIS will image the night side in near-infrared bands, and color and higher-resolution monochrome mosaics will be made of both the approaching and departing hemispheres.
* The UltraViolet and Visible Spectrometer, part of the probe’s Mercury Atmospheric and Surface Composition Spectrometer (MASCS), will capture profiles of emissions from atmospheric species versus altitude on both the day and night sides as well as observations of the exospheric tail on departure.
* MASCS’s Visible and InfraRed Spectrograph will observe the planet near closest approach to assess the chemical composition of clouds. It may also detect near-infrared returns from the surface.
* The MESSENGER Laser Altimeter (MLA) will measure Venus’ brightness at 1064-nm by using its pulse return detector as a passive sensor. MLA will also pulse its laser in an attempt to measure the range to one or more cloud decks for several minutes near closest approach.
* The Magnetometer will characterize the magnetic structure of the Venus bow shock and draping of the interplanetary magnetic field over Venus’ ionosphere while the Energetic Particle and Plasma Spectrometer will observe charged particle acceleration and plasma flows associated with the bow shock.

The Venus Express mission of the European Space Agency is currently operating in an elliptical polar orbit about Venus, and MESSENGER’s June planetary encounter together with the ongoing observations by Venus Express will permit unique observations of the Venus-solar wind interaction. To understand fully how the solar wind plasma affects and controls the Venus ionosphere and nearby plasma dynamics, simultaneous measurements are needed of the interplanetary conditions and the particle-and-field environment at Venus. The combined MESSENGER and Venus Express observations will be the first opportunity to conduct such two-spacecraft measurements."


EDIT: Don Merritt over at VEX Science Operations states that http://www.unmannedspaceflight.com/index.php?showtopic=4011&st=15&p=87153&#entry87153 of the joint science will occur in mid-June. I'm looking forward to it.

Posted by: NMRguy May 2 2007, 09:51 PM

http://messenger.jhuapl.edu/news_room/status_report_05_02_07.html
MESSENGER Mission News
May 2, 2007

MESSENGER completed a burn to set up the rapidly approaching second Venus flyby. Not everything is smooth sailing, however, as spacecraft "jitter" was detected during the burn, resulting in a slightly less than ideal trajectory. Scientists will analyze the attitude control system and tracking data to figure out the source of the problem, hopefully finding a solution before the May 25 trajectory correction maneuver that will put MESSENGER in the intended aim point of 337 kilometers above the surface of Venus.

Let's hope the engineers figure out the flutters in the spacecraft sooner than later.

Posted by: OWW May 26 2007, 09:20 PM

http://messenger.jhuapl.edu/news_room/status_report_05_25_07.html
MESSENGER Mission News
May 25, 2007

The MESSENGER trajectory correction maneuver (TCM-16) completed on May 25 lasted 36 seconds and adjusted the spacecraft’s velocity by 0.212 meters per second (0.696 feet per second). The movement targeted the spacecraft close to the intended aim point 337 kilometers (209 miles) above the surface of Venus for the probe’s June 5 flyby of that planet.

The maneuver started at 12:00 p.m. EDT. Mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., verified the start of TCM-16 about 7 minutes later, when the first signals indicating thruster activity reached NASA’s Deep Space Network tracking station outside Madrid, Spain.

“Today’s operation completed just as planned,” says Mission Operations Manager Andy Calloway of APL. “All subsystems were nominal going into the maneuver, and the burn cutoff occurred right at the expected time. Now that TCM-16 is behind us, we are focused on loading the Venus flyby command load to the spacecraft next week.”

Posted by: nprev May 26 2007, 10:35 PM

BTW, the Messenger site has a much improved interactive mission timeline well worth a look:

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/TimeLine_content.html

Looks like this coming January 14th we'll get to see unexplored territory not imaged by Mariner 10...go Messenger! smile.gif

Posted by: AlexBlackwell May 30 2007, 08:51 PM

http://messenger.jhuapl.edu/news_room/status_report_05_30_07.html
MEDIA ADVISORY: M07-060
May 30, 2007

Posted by: Greg Hullender Jun 1 2007, 08:37 PM

I note that they've updated the Messenger site to show Venus instead of Mercury.

http://messenger.jhuapl.edu/whereis/index.php#view_mercury

Even though the tag is still CALLED "view_mercury," of course. :-)

--Greg

Posted by: Littlebit Jun 4 2007, 01:58 PM

QUOTE (Messenger Mission News)
]In the coming evenings, sky watchers can acquaint themselves with the MESSENGER spacecraft mission to Mercury. Late afternoon on Tuesday, June 5, 2007, MESSENGER will fly within about 210 miles (340 kilometers) of the surface of the planet Venus, and get a gravity kick toward its ultimate destination, the sun-baked planet Mercury.


http://messenger.jhuapl.edu

Posted by: CAP-Team Jun 4 2007, 02:54 PM

The quote above suggests that the spacecraft would actually be visible to observers..
Would be nice, but I don't think you can see the spacecraft passing Venus

Posted by: Holder of the Two Leashes Jun 4 2007, 11:07 PM

Looking forward to "Mercury Flyby 1" on the web site countdown clocks in the next couple of days.

Here's wishing a successful Venus flyby with good science.

Posted by: RichardLeis Jun 4 2007, 11:17 PM

I am not sure if this is planned, but I would love to see a flyby movie like the MESSENGER team created for the August 02, 2005 Earth flyby. I cannot stop playing that movie over and over again...

I was surprised during a recent search for Venus global views by how few there seemed to be. Maybe I am just missing the good ones. I am so excited to see Venus fill a MESSENGER camera view.

Posted by: elakdawalla Jun 5 2007, 12:08 AM

I can confirm that the MDIS team does have an outbound movie planned to about 30 hours after closest approach. They'll be using 3 filters: one at 415 nm that should show the clouds pretty well, and two near-infrared wavelengths that they hope might get through to the surface (I have my doubts, but I can't fault them for trying; I'm keeping my fingers crossed.)

I have more details...later...after I get my story on the flyby posted tomorrow.

--Emily

Posted by: lyford Jun 5 2007, 12:44 AM

QUOTE (RichardLeis @ Jun 4 2007, 04:17 PM) *
I cannot stop playing that movie over and over again...

I agree, these videos are an extra benefit of these complicated multiple flyby gravity assist missions. After years of watching Star Trek, it's finally nice to really see the planets zoom by (albeit not in real time...)

I would like to see one of these movies start with the planet as a a point of light and zoom by until it fades to a point again.... some day!

Posted by: RichardLeis Jun 5 2007, 04:59 AM

Thanks for the info, Emily. Looking forward to reading your report, and to the first images.

QUOTE (lyford @ Jun 4 2007, 05:44 PM) *
I would like to see one of these movies start with the planet as a a point of light and zoom by until it fades to a point again.... some day!


Yes, that would be great!

Posted by: edstrick Jun 5 2007, 07:36 AM

"... was surprised during a recent search for Venus global views by how few there seemed to be. Maybe I am just missing the good ones..."

Few missions to Venus have done imaging. Mariner 10 was the first, Soviet Venera 9 and 10 orbiters took limited data, not full disk. Pioneer Venus Orbiter took extensive "Imaging Cloud Polarimeter" camera data including a lot of whole disk coverage but that's increasingly forgotten and may not be available, even from the NSSDC.. worth investigating. Galileo got some nice full disc images but a very limited amount. That's it, so far, besides Venus Express.

Posted by: tedstryk Jun 5 2007, 02:27 PM

I have been told that they are slowly working to put the PVO clould photopolarimeter on CD-ROM, but that right now it is only available in extremely arcane formats.

Posted by: gndonald Jun 5 2007, 03:52 PM

QUOTE (Holder of the Two Leashes @ Jun 5 2007, 07:07 AM) *
Looking forward to "Mercury Flyby 1" on the web site countdown clocks in the next couple of days.

Here's wishing a successful Venus flyby with good science.


I've just checked out the site and they seem to be showing both the 'Venus Flyby' and 'Mercury Flyby' captions with the clock showing the time to the Mercury flyby, hopefully there will be a site update soon.

Posted by: Littlebit Jun 5 2007, 06:14 PM

QUOTE (edstrick @ Jun 5 2007, 01:36 AM) *
That's it, so far, besides Venus Express.

Is the number of images released by the VE program still in the single digits?

Posted by: Greg Hullender Jun 5 2007, 07:11 PM

QUOTE (gndonald @ Jun 5 2007, 08:52 AM) *
I've just checked out the site and they seem to be showing both the 'Venus Flyby' and 'Mercury Flyby' captions with the clock showing the time to the Mercury flyby, hopefully there will be a site update soon.

Actually it still only shows the Venus flyby countdown; the other countdown is for Mercury Orbit Insertion, which is still a few years away. There will be a Mercury flyby in January 2008, and that's the countdown we're waiting for.

Another minor milestone -- Messenger should fly by Mercury's orbit in August. Mercury won't be there then, of course, but it's a cool event anyway.

--Greg

Posted by: JRehling Jun 5 2007, 08:56 PM

QUOTE (RichardLeis @ Jun 4 2007, 04:17 PM) *
I am not sure if this is planned, but I would love to see a flyby movie like the MESSENGER team created for the August 02, 2005 Earth flyby. I cannot stop playing that movie over and over again...

I was surprised during a recent search for Venus global views by how few there seemed to be. Maybe I am just missing the good ones. I am so excited to see Venus fill a MESSENGER camera view.



One of the better Venus images from spacecraft, lacking any facsimile of resolution, but having nice true color textures, is FROM Messenger already:

http://messenger.jhuapl.edu/the_mission/pictures/images/approach_venus_lg.jpg

I think one issue is that we "experientialists" like to see true color images, but they have little scientific value at Venus. For eye candy, I would like to see a movie in true color, but that would be a lot of bandwidth for eye candy alone. The UV/IR (if that's what the movie is limited to) will potentially interesting, but won't give me that feeling of looking out the window.

Posted by: volcanopele Jun 5 2007, 09:07 PM

QUOTE (elakdawalla @ Jun 4 2007, 05:08 PM) *
two near-infrared wavelengths that they hope might get through to the surface (I have my doubts, but I can't fault them for trying; I'm keeping my fingers crossed.)

At last year's LPSC, one of the members of the MESSENGER science team gave a preview of the Venus encounters. Now, it has been a while, but IIRC, they plan on imaging the surface by using one of their infrared filters to peer through one of the NIR windows and ratio those products with data from another NIR filter that will in effect remove the contribution from the lower atmosphere. This is basically the same technique we use for images of Titan's surface. Can anyone confirm this imaging strategy, or is this just wishful thinking on my part...

Posted by: elakdawalla Jun 5 2007, 09:21 PM

Louise wasn't that specific about the imaging strategy but she did say that they were using two NIR filters at, she thought, about 1 micron and about 1020 nm; and doing ratios seems to be a good reason to try two filters. The reason I'm doubtful that this will succeed is that I would have thought that if it turned out to be possible to see the surface this way, VIRTIS would already have done it. And it doesn't seem that Venus Express has managed to produce surface images. They have a less sharp imager but it has much higher spectral resolution -- it just seems that if this process works, it should already have been tried and found to succeed for VIRTIS.

--Emily

Posted by: JRehling Jun 5 2007, 10:05 PM

QUOTE (elakdawalla @ Jun 5 2007, 02:21 PM) *
Louise wasn't that specific about the imaging strategy but she did say that they were using two NIR filters at, she thought, about 1 micron and about 1020 nm; and doing ratios seems to be a good reason to try two filters. The reason I'm doubtful that this will succeed is that I would have thought that if it turned out to be possible to see the surface this way, VIRTIS would already have done it. And it doesn't seem that Venus Express has managed to produce surface images. They have a less sharp imager but it has much higher spectral resolution -- it just seems that if this process works, it should already have been tried and found to succeed for VIRTIS.

--Emily


I thought that's just what we saw here:

http://www.esa.int/esa-mmg/mmg.pl?b=b&type=I&mission=Venus%20Express&single=y&start=9

"The surface-temperature measurements were performed using the atmospheric windows located in the near infrared at 1.02, 1.10, and 1.18 microns, respectively. The radiation coming from the surface is affected by the thick cloud layer, so a ‘de-clouding’ algorithm had to be applied."

These are surface images in the sense of seeing the thermal gradients due to altitude. Given those wavelengths, we can not expect they are looking to see reflective albedo the way ISS does at Titan. At Venus, the thermal component should completely obliterate the reflected sun-based IR.

Posted by: Holder of the Two Leashes Jun 5 2007, 10:55 PM

QUOTE (Greg Hullender @ Jun 5 2007, 02:11 PM) *
Another minor milestone -- Messenger should fly by Mercury's orbit in August. Mercury won't be there then, of course, but it's a cool event anyway.


Cool event, true. But char broiled from another point of view. smile.gif

Posted by: edstrick Jun 6 2007, 09:56 AM

"...I think one issue is that we "experientialists" like to see true color images, but they have little scientific value at Venus. ..."

Eye candy, maybe, but don't knock the possibility. Messenger should periodically take a few sets of images using ALL spectral filters to map out the contrast of features in the clouds as a function of wavelength and look for wavelength varying features.

Mariner 10 took a very few sets of full disc UV, Blue and Orange filtered images. In the best set, the orange image showed a distinct dark band near the south polar collar, and a relatively bright collar. That dark band was NOT distinct in the UV image, just another dark band. It was darker in the blue image than other markings which were much weaker than in the UV.

There are more than one absorber in the clouds, and weak though the contrasts may be, seeing features change with wavelength is scientifically important. The near IR features Galileo saw were deeper and almost entirely uncorrelated with the UV/Blue features in the matching shortwave image.

Posted by: gndonald Jun 6 2007, 10:26 AM

She's made it biggrin.gif

See: http://tinyurl.com/27m2uj

Still no pictures though...

Posted by: remcook Jun 6 2007, 11:04 AM

QUOTE
The data acquired with all of the instruments should begin arriving back at the Deep Space Network tracking stations just after 12 p.m. EST on June 7, with more data coming down during the next few days. By June 8, we should have our color mosaic, as well as our laser altimeter observations;

Posted by: Littlebit Jun 6 2007, 01:35 PM

QUOTE
Late afternoon on Tuesday, June 5, 2007, MESSENGER will fly within about 210 miles (340 kilometers) of the surface of the planet Venus, and get a gravity kick toward its ultimate destination, the sun-baked planet Mercury...

Mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., said MESSENGER’s systems performed flawlessly as the spacecraft sped over the cloud tops of Venus at a relative velocity of more than 30,000 miles per hour, passing within 200 miles of the surface of the planet at 23:08 UTC (7:08 p.m. EDT).

200 miles? Was this an areobraking event?

Posted by: tedstryk Jun 6 2007, 01:49 PM

Littlebit, you are thinking kilometers. Granted, this is still within Venus' rarified exosphere, but that shouldn't be much of a factor.

Posted by: cndwrld Jun 6 2007, 03:27 PM

It looks like the Messenger Fly-By went just most extremely wonderfully nicely. Here's the press release.

For Immediate Release
June 5, 2007

Media Contact:
Paulette W. Campbell
(240) 228-6792 or (443) 778-6792
paulette.campbell@jhuapl.edu

MESSENGER Completes Second Venus Flyby,
Makes Its Way toward First Flyby of Mercury in 33 Years

NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft swung by Venus for the second time early this evening for a gravity assist that shrank the radius of its orbit around the Sun, pulling it closer to Mercury. At nearly 15,000 miles per hour, this change in MESSENGER’s velocity is the largest of the mission.

Mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., say MESSENGER’s systems performed flawlessly as the spacecraft sped over the cloud tops of Venus at a relative velocity of more than 30,000 miles per hour, passing within 200 miles of the surface of the planet at 23:08 UTC (7:08 p.m. EDT).

For 20 minutes during this closest approach, MESSENGER was within the shadow of Venus, and in the absence of solar power the probe relied solely on its internal battery. By 01:32 UTC (9:32 p.m. EDT) the battery had fully recharged, and the spacecraft was operating as planned.

“This second Venus flyby was a critical mission milestone on our craft’s circuitous journey toward Mercury orbit insertion,” declared MESSENGER principal investigator Sean Solomon, from the Carnegie Institution of Washington. “Not only did the maneuver sharpen the spacecraft’s aim toward the first encounter with Mercury in more than three decades, it presented a special opportunity to calibrate several of our science instruments and learn something new about Earth’s nearest neighbor.”

“The approach geometry is similar to that for the first Mercury flyby, allowing the seven instrumentation packages to be turned on and to operate collectively in science observing mode, just as they will be for Mercury,” noted MESSENGER Systems Engineer Eric Finnegan. “This event also marks the first time in flight that the entire instrumentation package will be operational simultaneously. Gathering approximately six gigabits of data, the spacecraft will take more than 630 images as well as make other scientific observations over the next few days.”

The team plans to image the upper cloud layers at visible and near-infrared wavelengths for comparison with earlier spacecraft observations. Magnetic field and charged particle observations will be made to characterize solar wind interaction and search for solar wind pick-up ions. Ultraviolet (UV)-visible and X-ray spectrometry will permit detailed observations of the composition of the upper atmosphere, and MESSENGER will search for lightning on the Venus night side.

“We are very excited with this next step in reaching our ultimate destination, Mercury,” says APL's Ralph McNutt, MESSENGER project scientist. “The data acquired with all of the instruments should begin arriving back at the Deep Space Network tracking stations just after 12 p.m. EST on June 7, with more data coming down during the next few days. By Friday we should have our color mosaic, as well as our laser altimeter observations, and these will be key in beginning several of the collaborative studies with our scientific colleagues on the Venus Express team.”

During this Venus encounter, MESSENGER joined forces with the European Space Agency’s Venus Express spacecraft, currently orbiting Venus, to make joint observations of the Venus environment. McNutt continued,” Although Venus’s atmospheric interaction with the solar wind was studied extensively by Pioneer Venus Orbiter in the 1980s, there has never before been an opportunity to measure simultaneously both interplanetary conditions and the particle-and-field characteristics at Venus. The combined MESSENGER and Venus Express observations will be the first opportunity to conduct such two-spacecraft measurements and should enable advances in our overall understanding of this interaction.”

Next up for MESSENGER is a trio of swings past Mercury in January and October 2008 and September 2009. During these flybys, MESSENGER will map most of the planet and determine surface and atmospheric composition; these data will be used to help plan priorities for the yearlong orbital mission, which begins in March 2011.

“The spacecraft and its operations team are poised to embark on the most intensive period of trajectory activities of the mission,” says Finnegan. “Over the next 18 months, the spacecraft will travel on a veritable inner-planetary roller coaster. Three passive gravity assists will be conducted, one by Venus and two by Mercury. Three Deep Space maneuvers will also be executed, using the large main engine of the spacecraft. In addition, 13 maneuvers utilizing smaller thrusters are possible in the event that periodic corrections to the trajectory are necessary along the way. All told, this adds up to a very high tempo of operations.”
MESSENGER Project Manager Dave Grant, of APL, says the work of the MESSENGER team of engineers and scientists in completing this second Venus flyby has been outstanding. “Our adherence to the designed mission trajectory and demonstrated performance of the science payload lends confidence to the ultimate success of the MESSENGER mission, and critical experience has been gained for managing future flybys and eventual orbit insertion at Mercury,” Grant says.

The MESSENGER project is the seventh in NASA’s Discovery Program of lower-cost, scientifically focused space missions. APL built and operates the MESSENGER spacecraft and manages the mission for NASA’s Science Mission Directorate, Washington.

For the latest news and images about the MESSENGER mission, visit: http://www.nasa.gov/messenger.

The Applied Physics Laboratory, a division of The Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For information, visit www.jhuapl.edu.

Posted by: elakdawalla Jun 6 2007, 05:42 PM

I've been forwarded a status report on MESSENGER that indicates that they've received telemetry indicating that there are hundreds of images now stored on the SSR, so it looks like they got lots of science done. Yay!

--Emily

Posted by: belleraphon1 Jun 6 2007, 10:09 PM

Venus... yeah...... thats was the signpost just ahead for........your next stop..... Mercury.

My children were not even a gleam in my eye the last time we visited Mercury... but I remember the Mariner 10 saga......

Planets in front of us, planets behind us, planets above and below us... What a wonderful time to be alive.....

Craig

Posted by: JRehling Jun 7 2007, 07:39 PM

QUOTE (edstrick @ Jun 6 2007, 02:56 AM) *
"...I think one issue is that we "experientialists" like to see true color images, but they have little scientific value at Venus. ..."

Eye candy, maybe, but don't knock the possibility. Messenger should periodically take a few sets of images using ALL spectral filters to map out the contrast of features in the clouds as a function of wavelength and look for wavelength varying features.


Very true.

I particularly would enjoy seeing movies of approach in the same true color bands by the same equipment, so that Messenger could give us comparable products for three different planets. It would be some seriously impressive eye candy if after NH, we could generate realistic flyby videos of the big nine planets -- maybe Ceres and Vesta, too. That'd make a memorable video montage.

Posted by: tedstryk Jun 7 2007, 08:12 PM

Do you mean DAWN?

Posted by: JRehling Jun 7 2007, 08:17 PM

QUOTE (tedstryk @ Jun 7 2007, 01:12 PM) *
Do you mean DAWN?


NH will flyby Pluto after Dawn arrives at Ceres, but only by a few months. NH will be the one to "finish" this tour of the larger sun-orbiting bodies (distant ones with no exploration plans withstanding).

Posted by: tedstryk Jun 7 2007, 08:47 PM

QUOTE (JRehling @ Jun 7 2007, 08:17 PM) *
NH will flyby Pluto after Dawn arrives at Ceres, but only by a few months. NH will be the one to "finish" this tour of the larger sun-orbiting bodies (distant ones with no exploration plans withstanding).


I thought you were referring to Dawn's Mars flyby in March 2009. Of course, should ESA get the whim to make one, we may have a Mars approach movie with a modern camera sooner.

Posted by: gndonald Jun 8 2007, 02:08 AM

The MESSENGER website appears to be down, I've made several attempts at access and all I get is:

QUOTE
Could not connect to mysql because Can't connect to MySQL server on 'sd-mysql' (4)


Looks like the pictures are going to take a little longer to appear than we expected.

Posted by: RichardLeis Jun 8 2007, 02:27 AM

QUOTE (gndonald @ Jun 7 2007, 07:08 PM) *
The MESSENGER website appears to be down, I've made several attempts at access and all I get is:
Looks like the pictures are going to take a little longer to appear than we expected.


I should probably stop checking the site so often...

Posted by: 4th rock from the sun Jun 11 2007, 08:27 PM

Well... no images yet... not even one. We are all spoiled by Cassini, MER and New Horizons... but I was expecting at least one or 2 images after a few days. I just hope everything is OK with the data!

Posted by: JRehling Jun 11 2007, 09:30 PM

QUOTE (4th rock from the sun @ Jun 11 2007, 01:27 PM) *
Well... no images yet... not even one. We are all spoiled by Cassini, MER and New Horizons... but I was expecting at least one or 2 images after a few days. I just hope everything is OK with the data!


The Earth video was released 24 days after the flyby. It's tough, but we've gotta have patience.

Posted by: Toma B Jun 12 2007, 07:29 AM

QUOTE (4th rock from the sun @ Jun 11 2007, 10:27 PM) *
We are all spoiled by Cassini, MER and New Horizons...

Well Rosetta did a good job un-spoiling some of us.... mad.gif mad.gif mad.gif

Posted by: 4th rock from the sun Jun 12 2007, 12:25 PM

I don't have any problem in waiting for the images. I'm just worried with the general trend that seems to show that when raw images aren't available soon... you never get to see any finished products. I understand that on most cases at least pre-processing (Flat fielding, bias subtraction, etc) must be done, and it takes time. What I fear is getting the data and doing nothing with it, as happened on Roseta and VEX, for example. Let's hope this is not the case smile.gif

Posted by: monitorlizard Jun 13 2007, 12:10 PM

Perhaps the MESSENGER team is waiting until they get enough results processed to present in a news conference. If it is a joint news conference with Venus Express (which would be considered more newsworthy), it would take additional time to coordinate and prepare.

Posted by: cndwrld Jun 13 2007, 12:49 PM

VEX and Messenger are both waiting for the data to even get to the ground. Both have low data rates at the moment. So no one is hiding data (at least not yet). In worst case, the VEX data for Virtis won't even get all downlinked until 21 June. I think all Messenger data may be down now; I heard something about it. But they also took a while to get it. And if it is all down, it was only in the last couple days.

Posted by: 4th rock from the sun Jun 13 2007, 01:26 PM

Thanks for the info, it makes sense. Downloading data off two spacecraft, with limited tracking infrastructure (don't know what is used for VEX, perhaps just ESA's antennas) does take a lot of time. Raw data are not JPGs, each just KB in size. We are talking several MB so the "delay" is justifiable. Perhaps a good way to make this facts more understandable to the public hould be to put a download bar on the site, next to the countdowns.
Anyway, lets wait then and hope for spectacular results from both missions and wish a very productive work for the teams involved!

Posted by: Littlebit Jun 13 2007, 02:32 PM

QUOTE (monitorlizard @ Jun 13 2007, 06:10 AM) *
Perhaps the MESSENGER team is waiting until they get enough results processed to present in a news conference. If it is a joint news conference with Venus Express (which would be considered more newsworthy), it would take additional time to coordinate and prepare.

That would be my worst nightmare: 2010: Messenger has now been in orbit about Mercury for two years, and all data is being embargoed until the Venus Express data up through the joint observations, made three years ago, are released rolleyes.gif

Posted by: cndwrld Jun 13 2007, 04:11 PM

I was going to show a plot of our VEX data downlink, which would show how much was stored in the on-board buffers and when it is dumped. But I can't figure out how to post an image.

But the VEX Virtis instrument data (the imaging spectrometer) won't be totally down (worst case) until 19 June (but may be down a couple days before that); all the other instruments should be down now.

I hear that all the Messenger data is down now. Reports are that the closest approach was within 5 Km of the target, which is great.

For VEX, we've been regularly analyzing data for a while now. Even so, it may not be trivial to process what the instrument teams have, because it was taken in a segment of the orbit where we've never taken data before. For Messenger, they are going to have to figure out what they have, and it may take a while for them to figure out what it is they are seeing. Some of the instruments are designed to work with rocks, not clouds. Shining a laser altimeter at clouds might make for messy data if you haven't seen it before.

ESA is planning a web site update on the fly-by within two or three weeks. I think the hope is that it will include a couple Messenger images. Keep in mind that the Messenger team will want to publish papers on the fly-by. If they release something now, it may be considered 'published' and journals won't accept papers on it. So they can't put out very much, or they risk running into trouble with editors.

Hope that helps.

Posted by: RichardLeis Jun 13 2007, 04:52 PM

I will continue to wait patiently and only check the MESSENGER website every hour instead of several times an hour. smile.gif I do not envy the MESSENGER team their task, and whenever they are ready to release data is fine with me.

Posted by: volcanopele Jun 13 2007, 04:58 PM

Even if they have a lot of image processing ahead of them, I would have thought that at least one or two, distant color images could have been released to at least show that they have data, it looks cool, and that there is more to come. Such an image wouldn't require that much processing, compared to the surface data they are trying to get, which from my own experience with Titan data, I know to be very patient for, or the mosaics they designed, which from my own experience, I know can't be done overnight.

Posted by: dvandorn Jun 13 2007, 05:44 PM

QUOTE (cndwrld @ Jun 13 2007, 11:11 AM) *
Keep in mind that the Messenger team will want to publish papers on the fly-by. If they release something now, it may be considered 'published' and journals won't accept papers on it. So they can't put out very much, or they risk running into trouble with editors.

Now, that is an extraordinary statement. I know that I, for one, have *never* heard of any such problem plaguing the various researchers working with the MER or Cassini images (which are released as soon as they are received). I can understand that the various non-imaging instruments may take some time to process and interpret, but images? Especially jpegs of the images?

If it is truly the case that anyone on ANY research team working with planetary probes feel they must sequester ALL of their images until they have a chance to publish, then we (the taxpayers who are PAYING for their precious probes, often also paying their salaries) ought to put pressure on our representatives to force at least limited release of imagery as close to real-time as possible. Playing the game of "Oh, my editors might give me hassles if anyone sees any of these images before we publish" is just plain unacceptable in this day and age. Period.

-the other Doug

Posted by: RichardLeis Jun 13 2007, 11:51 PM

Spacecraft operations and public releases are processes that are changing, and I think we should continue to be patient. It is true that teams use to hold onto data until they could get all the science out of them that they could. This philosophy is slowly changing, thanks to the MER team and others.

I know we are taxpayers (and I guess part of my income also comes from other taxpayers) but taxpayers also do not always know the ins and outs of the process. Sometimes their expectations are greater than reality. While it can be frustrating, change does come.

From experience, I know that sometimes the reasons why there are delays has nothing to do with philosophy, but everything to do with technical or logistical matters. Sometimes there are unexpected processing hardware and software failures, deaths in the family, unexpected DSN coverage issues, etc. Often there is not time to give the public the full reckoning to which they may feel entitled.

The desire to release data as quickly as possible is spreading through the community (and may even hit Europe someday!) smile.gif The public, the taxpayer, should be careful with their sense of entitlement and let the process unfold, unless, of course, they choose to enter the field and help introduce new ideas.

Posted by: Littlebit Jun 14 2007, 02:14 PM

The entire scientific world was fascinated by the almost real-time release of Voyager imagery. The audience is smaller, but the same is true for both Cassini and the MERs. NHs has been wonderful.

Nobody is fascinated with that Venus probe that has only released a handful of images...i forgot the name.

Messenger? Live up to yor name.

Posted by: ugordan Jun 14 2007, 02:40 PM

Littlebit, real-time release of Voyager imagery was only possible because most data was coming down, well, real-time. As for RAW image pages, that's a very nice practice, but it's only the mission folks' free will that enables such sorts of goodies for us amateurs.

I have to add that while I'm also looking forward to that departure movie of Venus, I'm expecting it to be pretty underwhelming (I'd like to see something other than a heavily processed sequence, a natural-ish color view instead), mainly a shrinking crescent with very little cloud structure discernible in the visible wavelengths. Certainly a lot less inspiring than that cool Earth departure sequence. Out of all 4 inner rocky planets, only Earth and Mars are photogenic enough (and rotate fast enough) for those kinds of movies to have a "wow" factor.
I'll be glad to be proven wrong, though!

Posted by: djellison Jun 14 2007, 02:42 PM

Can we calm down the witch hunt please. We know they're going to release it all at some point ( look at the data of the Earth flyby - stunningly published in ful ) - give them time.

Doug

Posted by: lyford Jun 14 2007, 03:11 PM

Well spoken! Don't shoot the MESSENG.... uh, never mind.

Posted by: Stu Jun 14 2007, 09:27 PM

Hey, http://www.nasa.gov/mission_pages/messenger/multimedia/venus_flyby.html are up... smile.gif

Posted by: ugordan Jun 14 2007, 09:37 PM

Awe-inspiring, aren't they? smile.gif

BTW, full-res images http://messenger.jhuapl.edu/the_mission/flyby_movies.html.

Posted by: Stu Jun 14 2007, 09:47 PM

Very... white... smile.gif

Looking forward to more detailed images.

Seriously tho, I think it's very cool that on the next clear night I'll be able to stare up at the sky and when I look at Venus blazing like a lantern in the NW I can say "probe just passed there..." When I look at Mercury glittering above the trees I can say "probe heading there..." When I look at Saturn to venus' upper left I can say "probe orbiting that..." When I look at Jupiter hanging above the southern horizon I can say "probe just passed there" and then, before dawn, if I can spot Mars shining in the dusk glow I can also say "probes BESEIGING that planet..." rolleyes.gif

Posted by: AlexBlackwell Jun 14 2007, 09:56 PM

QUOTE (Stu @ Jun 14 2007, 11:27 AM) *
Hey, http://www.nasa.gov/mission_pages/messenger/multimedia/venus_flyby.html are up... smile.gif

Has anyone done a count to see if we've the public has received more Venus images from MESSENGER than from Venus Express?

Posted by: djellison Jun 14 2007, 10:10 PM

Give them a week or two more - and Messenger will outstrip VEX very easily.

Doug

Posted by: Stu Jun 14 2007, 10:23 PM

QUOTE (djellison @ Jun 14 2007, 11:10 PM) *
Give them a week or two more - and Messenger will outstrip VEX very easily.


Which is pretty depressing and annoying when you stop and think about it...

... but this isn't the place for such negative thoughts. Congratulations to the MESSENGER team on a successful fly-by, and thanks for the first images! smile.gif

Posted by: AlexBlackwell Jun 14 2007, 10:41 PM

I might have missed it but did anyone else see this http://solar-heliospheric.engin.umich.edu/shrgpub/news_images/FIPS_V2_release_08Jun2007.jpg?

Posted by: elakdawalla Jun 14 2007, 11:43 PM

Bland as it may seem, there's actually some cloud details visible in the global view. I monkeyed around a bit with high-pass filtering and such in Photoshop and came up with this version, which displays a little more detail. Can anyone do better than this? (If you can, I'd love an explanation of what you do.)

--Emily


Posted by: lyford Jun 15 2007, 12:43 AM

Hey! What did you do to Planet Cue Ball!?!?!?

Seriously, nice to see the spigot opening up a bit....

Posted by: Bjorn Jonsson Jun 15 2007, 01:17 AM

Here's my version:



This one has been sharpened with a high-pass filter that also removes illumination effects (limb darkening and darkness near the terminator). I could have increased the contrast even more to make large scale features (even) more obvious but if I do so the image becomes annoyingly noisy.

Posted by: AlexBlackwell Jun 15 2007, 01:22 AM

Nice work, Bjorn.

Posted by: 4th rock from the sun Jun 15 2007, 12:12 PM

OK, after initial negative comments about a the lack of image releases, I all involved give my congratulations for the images. They have surpassed my expectations. I think that these images where taken with a violet-blue filter, so they show some cloud details while remaining within visible wavelengths. Very very interesting and comparable to earth based amateur observations (there are some very nice ones).

Posted by: JRehling Jun 15 2007, 05:39 PM

QUOTE (4th rock from the sun @ Jun 15 2007, 05:12 AM) *
OK, after initial negative comments about a the lack of image releases, I all involved give my congratulations for the images. They have surpassed my expectations. I think that these images where taken with a violet-blue filter, so they show some cloud details while remaining within visible wavelengths. Very very interesting and comparable to earth based amateur observations (there are some very nice ones).


When I first started doing color photography (back in the day), I examined an image of a snow-covered field and was amazed, if I focused within the "snow" how much color there was, and how complex. The image was taken maybe an hour or two before sunset.

I bring this up because I eagerly anticipate seeing a true color version of this approach image. What looks like a hologram diffraction pattern in one filter may be very interesting in RGB.

I suspect that the bright-adapted human eye would see a pretty neat image in a Venus flyby, shimmer like a pearl. 99% "white", but with subtle iridescent patterns that made it much more interesting than 100% white. I'm hopeful that this flyby will give us this feeling for the first time from a spacecraft.


OT: A nice UV one from Earth:

http://www.lpl.arizona.edu/~rhill/alpo/venustuff/alert/v20070422b.jpg

Posted by: RichardLeis Jun 16 2007, 05:39 PM

It is the hint of cloud structure that really makes this view of Venus so interesting to me. Awesome job to those who pulled out even more structure.

Posted by: nprev Jun 16 2007, 09:41 PM

QUOTE (dvandorn @ Jun 13 2007, 10:44 AM) *
Now, that is an extraordinary statement. I know that I, for one, have *never* heard of any such problem plaguing the various researchers working with the MER or Cassini images (which are released as soon as they are received).
-the other Doug


Yeah...My personal hypothesis is that professional insecurity (esp. on the part of APL, which is competing directly in this mission with JPL) is the prime driver here. Hopefully this will not influence release of the pending Mercury flyby imagery, which of course should attract mass media interest... sad.gif

Posted by: cndwrld Jun 18 2007, 11:33 AM

FYI, I'm told that the Messenger images have almost no contrast because they are taken at 480 nm.
VMC and VIRTIS on Venus Express are imaging at 365 nm, which gives far better contrasts.

Posted by: 4th rock from the sun Jun 18 2007, 12:16 PM

480 nm means deep blue, so it's inside the visual spectrum. Therefore, the contrast is low, but the cloud details revealed would be visible to the naked eye.

Posted by: nprev Jun 18 2007, 02:31 PM

True. Do you suppose that the unaided eye at C/A would see at least some of the details that Emily http://planetary.org/image/venus_messenger_globe_filtered.jpg with this degree of clarity? (Probably have to be wearing shades as well; my eyes hurt at the thought of staring at an object a third closer to the Sun than Earth with such a high albedo...)

Posted by: dvandorn Jun 18 2007, 03:18 PM

Remember, "shades" are just another form of filter. What spectral range will you be getting through your preferred shades? That will make some difference in terms of the details that will be visible to you. Also, polarization will make a difference, too.

Back during Apollo, the most common sunglasses were green-tinted. The Apollo 12 crew really needed the sunglasses at times, but Pete Conrad decided not to use them at times because he didn't have nearly the visual acuity on the lunar surface through the green-tinted lenses that he had without them. So, the wavelengths passed through your shades, and those blocked, do make a noticeable difference.

-the other Doug

Posted by: um3k Jun 18 2007, 03:44 PM

It may be visible to the naked eye, but it would appear much more as a color variation than a brightness variation.

Posted by: JRehling Jun 18 2007, 05:04 PM

QUOTE (um3k @ Jun 18 2007, 08:44 AM) *
It may be visible to the naked eye, but it would appear much more as a color variation than a brightness variation.


My hunch is that Venus anywhere but near the terminator would overwhelm a lot of the sensitivity that would otherwise be possible, and you would indeed need to pare down the light.

If you were hellbent on avoiding a spectral filter, you could use a pinhole or grated screen to view it through.

Definitely the level of luminosity sensed would change the kinds of details seen. For what it's worth, I find that with sunglasses, I see color in sundogs and subtle rainbows that are invisible to the naked eye. And I could believe that a sundog could rival or surpass the luminosity of Venus's cloudtops since it's backscattered direct sunlight. This is not a case of my sunglasses creating the rainbow -- it's not there in every bright light. It just improves the perception when it's real.

Posted by: AlexBlackwell Jun 18 2007, 05:08 PM

Here's a paper that one should download now while it's free:

MESSENGER Mission Design and Navigation
James V. McAdams, Robert W. Farquhar, Anthony H. Taylor and Bobby G. Williams
Space Sci. Rev., In Press (2007)
DOI 10.1007/s11214-007-9162-x
http://www.springerlink.com/content/g62rru8048220547/fulltext.pdf

Posted by: J.J. Jun 21 2007, 01:58 PM

Though that's within the visual band, the detail in that image is still extremely subtle; I find it hard to believe it would be detectable through Earth's atmosphere with the naked eye. To be sure, MESSENGER's imagery covers only a single day on a planet with (presumably) significant atmospheric variations, but...

In Patrick Moore's Venus (recommended, if you haven't read it), he talks about an old experiment in which people looked through a telescope at a featureless ping-pong ball (IIRC, the same size as Venus would appear through a telescope from Earth), and who drew what they saw. Many of the volunteers drew subtle shadings and variations that simply weren't there--in other words, like many terrestrial observations of Venus. While UV detail is undeniable, I'm thus increasingly skeptical of earthbound visible observations.

For my part, only the prominent cusps Venus sometimes exhibits from Earth are possible visible features; if real features, they roughly correspond to the polar vortexes. As advanced as CCD imagery is today, I have yet to see a visible image that shows any hint of terminator irregularities, and even the cusps are absent.

Just my two bits--though for the record, I have a long-time interest in Venus. It's just that the amateur astronomer in me hoped that there would be more visual detail than that, and the lack thereof makes such skeptical studies as those cited by Moore increasingly relevant, IMO.

Posted by: 4th rock from the sun Jun 21 2007, 11:33 PM

Almost daily amateur Venus images can be seen http://alpo-j.asahikawa-med.ac.jp/Latest/Venus.htm.

A nice visual image from that page is http://alpo-j.asahikawa-med.ac.jp/kk07/v070612z.htm. One of the polar areas is noticeable brighter, and that would be visible in a good telescope. As for more subtle details, one must be cautious in interpreting drawings and visual impressions. But in general, some brighter areas around the poles can be see from Earth.

Posted by: 4th rock from the sun Jun 21 2007, 11:34 PM

Almost daily amateur Venus images can be seen http://alpo-j.asahikawa-med.ac.jp/Latest/Venus.htm.

Here is a nice visual image from that page:
.
One of the polar areas is noticeable brighter, and that would be visible in a good telescope. As for more subtle details, one must be cautious in interpreting drawings and visual impressions. But in general, some brighter areas around the poles can be see from Earth.

Posted by: edstrick Jun 22 2007, 08:49 AM

I took a crack at the full-disk messenger pic of Venus with my band-pass filtering and here's what I got. I think it preserves some larger scale features than the previous high-pass filtered version. The real solution is to calculate a global photometric function to match the image and divide the image by the function. Not trivial, and it can still go crazy at the limb and terminator.

 

Posted by: AlexBlackwell Jun 22 2007, 04:54 PM

Another freebie from Space Science Reviews:

MESSENGER: Exploring Mercury’s Magnetosphere
James A. Slavin et al.
Space Sci. Rev., In Press (2007)
DOI 10.1007/s11214-007-9154-x
http://www.springerlink.com/content/90q1l830752115l0/fulltext.pdf

Posted by: CAP-Team Jul 6 2007, 08:56 AM

It's been almost a month now since the Venus flyby, still no new images on the website sad.gif

Posted by: brellis Jul 6 2007, 08:32 PM

Do you hear that sound? It's the sound of me resisting the temptation to bag on the PR efforts from ESA tongue.gif

(as in comparing the lack of return to the pace of return from Mars Express/Venus Express)

Posted by: cndwrld Jul 10 2007, 03:30 PM

I'm at a Venus Express science working team meeting right now, and the Messenger team is here to show us some early results of their second Venus flyby. The joint press release with ESA is moving forward, but there are a lot of cooks working on the soup so things are moving slower than anyone would like. And it isn't just the ESA end slowing it down. It sounds likely that some results will start getting posted next week. And then will trickle out after that. It doesn't look like there will be a big dump of data onto the web site.

One issue is that the Messenger team is hoping to publish some of their results in Science, and Science has an embargo on already-published material. So Messenger needs to be careful that they don't release something, and then not be able to publish it in the special issue of Science.

I wouldn't get too excited about the images they'll be posting from the Messenger flyby. The Messenger guys showed some of their early data at our meeting, in Rome on Monday. It is important to understand that their instruments are not well suited for Venus. For Messenger, this was mostly just a dry run of the flybys they will perform of Mercury itself; they do two Mercury flybys before going into Mercury orbit. This was the first time they turned on all their instruments and performed with them all together in a flyby mode. The first time they went past Venus, they couldn't do it because of various thermal constraints.

The camera images are at bad wavelength windows, so you get a white cue ball. The lidar doesn't work well with the clouds. There's useful science, but the images are not the most exciting pictures you'll ever see.

As a dry run of a flyby, though, it was very successful. Everything worked great. So in 2008, we can expect some great images of Mercury.

Posted by: brellis Jul 10 2007, 06:48 PM

hi cndwrld

Thanks much for the update. I'm very glad to hear everything went well. Venus is a tough planet to image, indeed!

Posted by: mchan Jul 26 2007, 05:12 AM

Additional Venus flyby images are up:

http://messenger.jhuapl.edu/the_mission/flyby_movies.html

Posted by: Ken90000 Jul 26 2007, 09:12 PM

I'm not seeing anything new there.

Posted by: mchan Jul 27 2007, 02:45 AM

I was referring to the video link for the Venus departure sequence. Not really new images, but a repackaging of released ones. Sorry about the misrepresentation.

Posted by: edstrick Jul 27 2007, 07:50 AM

The departure sequence will be vastly more interesting when a photometric function of the shading across the disk is applied to the images, and then the images are displayed at full resolution, even better, at constant scale, matching the first in the sequence.

Posted by: cndwrld Jul 27 2007, 09:55 AM

Messenger Fly-By of Venus

The ESA web page for the Messenger fly-by is on-line, on the ESA Space Science page, at
http://www.esa.int/esaSC/index.html

If you click on the third story, labeled, "Venusian rendezvous results: chapter one", you go to the dedicated fly-by page at:
http://www.esa.int/esaSC/SEMVN4HYX3F_index_0.html

The fly-by page can also be reached from the dedicated Venus Express page at:
http://www.esa.int/SPECIALS/Venus_Express/index.html

Posted by: mchan Aug 4 2007, 05:59 AM

While counting down to the Phoenix launch to Mars, this http://messenger.jhuapl.edu/news_room/status_report_08_03_07.html recalls that 3 years ago yesterday, Messenger launched to Mercury. It is approaching perihelion within a month and the report mentions it will be the closest any 3-axis stabilized spacecraft has ever approached the Sun. Only the two Helios probes required more sun block.

Posted by: Greg Hullender Aug 4 2007, 09:56 PM

I'm sure everyone has already seen these, but I've been taking a closer look at the details of the three flybys with an eye towards how much new information we should expect from each. Right off the bat, I realized all the flybys have to come from the night side, so the coverage may be more limited than I'd hoped. Still, anything new will be nice.

Looks like the first one -- this coming January -- will catch pics of maybe 2/5 of the surface that Mariner 10 couldn't see -- maybe less.

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby1Files/Mercury1AboveNorthPoleFull.jpg

Then the one a year from September fills in that annoying empty stripe plus a bit of the terrain that the first flyby missed.

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg

Sadly, the third flyby -- TWO years from next month -- doesn't appear to pick up anything the second one didn't see.

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg

However the very first orbit -- in March 2011 -- looks likely to fill in most of the remaining gaps.

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryOrbitInsertionFiles/MercuryOrbitInsertionAboveNorthPoleFull.jpg

Of course I realize a lot depends on the field of view of the cameras and exactly how they use them during each encounter. (And from how far away they can get useful shots.)

Does anyone know if they have specific imaging plans? And if they'd like to post them? :-)

--Greg

Posted by: jamescanvin Aug 5 2007, 09:30 AM

Greg, you seem to have the 3rd flyby linked twice, missing the second (although they are very similar).

If you have the bandwidth the animations of the flybys from MESSENGERS p.o.v are VERY illuminating.

http://messenger.jhuapl.edu/the_mission/ani.html - scroll down.

James

Posted by: JRehling Aug 7 2007, 10:54 PM

QUOTE (Greg Hullender @ Aug 4 2007, 02:56 PM) *
I'm sure everyone has already seen these, but I've been taking a closer look at the details of the three flybys with an eye towards how much new information we should expect from each. Right off the bat, I realized all the flybys have to come from the night side, so the coverage may be more limited than I'd hoped.
[...]
Sadly, the third flyby -- TWO years from next month -- doesn't appear to pick up anything the second one didn't see.


The simple equation here is that all of the flybys take place with Mercury in roughly (but not exactly) the same location in its orbit, and for any such fixed location, Mercury can only be rotated in one of two ways (180 degrees apart from each other). So you can already determine that multiple such flybys will either buy you:

1) Multiple views of the same hemisphere (as was the case with Mariner 10).

or

2) Some views of one hemisphere and some of the exact opposite hemisphere.

Because Messenger represents case (2), it will in principle "see" virtually all of Mercury's surface. But some of that will be only from rather far away and some will be on the limb, compromising resolution in one dimension.

Seeing the Mariner territory in multispectral glory will also be a nice bump up in our knowledge.

The first flyby will give us a nice view of a half Mercury -- essentially all new to us -- as it departs. The other two flybys will show us some all-new crescents on the approach, but show fairly little that's new on the departure.

The best details I have seen are here:

http://astrogeology.usgs.gov/Projects/ISPRS/MEETINGS/Houston2003/abstracts/Prockter_isprs_mar03.pdf

<<At each flyby, a 3-color approach movie will be acquired, beginning 30 hours before the encounter
and ending about 1 hour before closest approach. A departure movie, also in 3 colors, will be obtained at
corresponding times on the way out from Mercury. Color images will be acquired in all 11 filters during
approach and departure, at about 5 km/pixel, and a high resolution (1-km/pixel) 11-color mosaic will be
obtained near to closest approach. In addition, a color photometry sequence of the same surface location
will be taken at a range of phase angles. Monochrome mosaics of the surface will be acquired at
resolutions of 500 m/pixel during approach and departure, and up to 60 m/pixel at closest approach.
In total, ~75% of the planet, including the previously unseen hemisphere, will be imaged in monochrome
at a resolution of ~500 m/pixel, and in color at 2.4 km/pixel or better.>>

Seeing as how the planet is about 5000 km in diameter, that means excellent detail from a global perspective if you're looking for an "eye candy" background screen of Mercury. In addition, I surmise that of the 25% that will not be seen in the flybys, about half will be in Mariner territory, meaning that about 88% of the planet will have been mapped after the second Messenger flyby. That's only 14 months away.

Posted by: Ken90000 Aug 7 2007, 11:03 PM

Are these figures still accurate? The publication seems to imply a July 2007 and Aprill 2008 flyby. It may have been written before the launch slipped.

Posted by: JRehling Aug 8 2007, 09:19 PM

QUOTE (Ken90000 @ Aug 7 2007, 04:03 PM) *
Are these figures still accurate? The publication seems to imply a July 2007 and Aprill 2008 flyby. It may have been written before the launch slipped.


That's a good point. The overall mission plan changed quite a bit. My guess is that the flybys are qualitatively similar to the ones in the original plan, arriving from and flying over the night side, approximately the same closest approach... and so, I don't see any reason why the general plan couldn't hold constant (movies from -3h to -1h and +1h to +3h). Nor do I see why the coverage (~75%) would change, or the likelihood that half of what is missed would be in Mariner territory. I think the description will still hold even with the different mission plan. If it changed, it would be for some other reason.

Posted by: JRehling Aug 9 2007, 02:43 AM

An added note, regarding the putative Skinakas basin, the first flyby might show the eastern rim of the basin on the terminator, if the basin is truly huge. But the second and third flybys will show most of the putative basin area conveniently on the limb in the approach images. Since these images will represent well over an order of magnitude improvement in resolution over adaptive optics imaging, the second flyby should definitively settle the question of whether or not the basin exists.

Posted by: gcecil Aug 10 2007, 11:43 PM

The slipped flyby dates are Jan. 14, 2008, Oct. 7, 2008 and Oct. 1, 2009. Orbit insertion will be March 18, 2011. However, the exact dates after the first flyby may change slightly. On the 3 flybys most of the surface not seen by Mariner 10 will be imaged. Imaging sequences remain as described a few messages back.

There have been NO adaptive optics observations of Mercury. The sky is too bright even in twilight for the natural & laser guide stars required. Only short-exposures selected to minimize wavefront corrugation, which have attained ~100-150 km resolution.

Posted by: Greg Hullender Aug 11 2007, 05:20 AM

Can you tell us at what resolution ranges Messenger will be able to image the previously-unobserved terrain during the flybys?

--Greg

Posted by: gcecil Aug 12 2007, 03:13 PM

QUOTE (Greg Hullender @ Aug 11 2007, 01:20 AM) *
Can you tell us at what resolution ranges Messenger will be able to image the previously-unobserved terrain during the flybys?

--Greg


See 6 posts up. For comparison, radar has attained down to ~4 km over much the equatorial to mid-latitudes of the Mariner un-imaged hemisphere, with some N/S Doppler ambiguity.

And here's the resolution coverage from Mercury orbit. If they have fuel left after phasing burns during their year of mapping, I imagine that they'll adjust the high-point to extend sampling of the magnetosphere. They won't have enough fuel to adjust the inclination to improve resolution across the S high latitudes. But first let's survive the flybys, orbit insertion, phasing burns ...

Posted by: edstrick Aug 13 2007, 07:39 AM

It's also worth realizing that like with the lunar highlands, but perhaps even more so, high resolution imagery tends to be less than impressive in what it reveals. The impact cratering of the highlands and much of mercury is "making the rubble bounce" cratering. The Mariner 10 high resolution images, with resolution down to some 150 <flyout> and 250 <approach> meters/pixel <somebody see what the real numbers are, I don't remember> are less than impressive.

With much more coverage, there will be scattered images with impressive features showing up at high rez. but.... and it's a big but.

Posted by: tedstryk Aug 13 2007, 11:20 AM

QUOTE (edstrick @ Aug 13 2007, 07:39 AM) *
It's also worth realizing that like with the lunar highlands, but perhaps even more so, high resolution imagery tends to be less than impressive in what it reveals. The impact cratering of the highlands and much of mercury is "making the rubble bounce" cratering. The Mariner 10 high resolution images, with resolution down to some 150 <flyout> and 250 <approach> meters/pixel <somebody see what the real numbers are, I don't remember> are less than impressive.

With much more coverage, there will be scattered images with impressive features showing up at high rez. but.... and it's a big but.


For the first encounter, the highest resolution flyout image is 82 meters/pixel and 121 meters/pixel inbound.

The second encounter only got down to about 430 meters/pixel.

For the third encounter strips, the highest resolution usable images are about ~40 meters per pixel. The highest resolution good quality images are at about ~17 meters per pixel. There are a few at ~15 meters per pixel, but are underexposed to the point of uselessness (that coming from me!).

Posted by: JRehling Aug 13 2007, 04:04 PM

QUOTE (edstrick @ Aug 13 2007, 12:39 AM) *
It's also worth realizing that like with the lunar highlands, but perhaps even more so, high resolution imagery tends to be less than impressive in what it reveals. The impact cratering of the highlands and much of mercury is "making the rubble bounce" cratering. The Mariner 10 high resolution images, with resolution down to some 150 <flyout> and 250 <approach> meters/pixel <somebody see what the real numbers are, I don't remember> are less than impressive.

With much more coverage, there will be scattered images with impressive features showing up at high rez. but.... and it's a big but.


This is a good point. But no one's accusing Mercury of being the eye-candy champion of the solar system. I think there'll still be oodles of interesting results from the imaging, with a number of reasons why it should be more interesting than the lunar highlands.

While Luna is sort of two-toned, with the highlands being laid over with maria, Mercury has a lot more surface of an age which is, qualitatively speaking, intermediate between the two... there are some plains that are fairly smooth but much more heavily cratered than the lunar maria. The implication has always been, I think, that Mercury's surface remained molten past the early heavy bombardment.

The volcanic plains on Mercury mix some complex overlays of different eras/sources of lava flooding, as the re-analysis of Mariner "color" data by Robinson and Lucey showed:

http://www.psrd.hawaii.edu/Jan97/MercuryUnveiled.html

That was obtained only for limited coverage of the planet, and only from 2 filters! Messenger is going to map the whole planet in 11 filters, and I think we'll end up with an interesting story about how this planet spent its entire history of volcanism. That's something you can't really do with the bigger terrestrial planets, whose atmospheres (and ongoing tectonics, etc) have paved over and eroded. You can look at Mercury and see a world that was, in a sense, Io for a while, with all of that action having ended a long time ago, then frozen forever. Imagine having the data from an orbiter that circled Mars 3 billion years ago and showed us its surface from then. In some respects, that's what we'll see with Messenger.

Except for the top few mm. Because the other interesting thing going on is the intense solar weathering, radiative and solar wind (?). Mercury receives over 10.5 times as much solar radiation at perihelion than the Moon does. With its quirky tidal synchrony and elliptical orbit, different areas see greatly varying exposure to the full glare, so there should be a complex story behind the solar weathering. That's stuff that shows up fine at modest resolution, so long as we can get all 11 colors on the various crater rays, etc.

Finally, there's some intrigue around the sputtering atmosphere, and the fact that it seems to emanate from special locations (mainly, fresh craters?) on the planet's surface. I think any imaging of those areas will be interesting. I get the idea that it is a byproduct of solar weathering, but maybe it can be pinpointed to particular surface features. Faults? Rays?

Mercury's in an interesting class -- in many ways unique. It shares a common size with Ganymede, another world with a semi-history of an active surface that is now frozen. It shares approximate surface composition with the Moon, but a very different history of cooling/impacts. It's got the unique scarps due to planetary contraction. And an atmosphere that is just thin enough that we can link its outgassing with particular locations. I think that Messenger's resolution will do a nice job of revealing all of these dynamics. Even if, at a glance, it ends up looking like a whole lot more of what we already see in the lunar highlands (or Rhea, etc.).

Posted by: edstrick Aug 14 2007, 08:18 AM

Indeed... we need global coverage at decently high resolution. In some ways, I'm more interested in the hints of primordial crust composition variations and later (but heavily battered) volcanic overprints, and still later visible volcanism that the multi-spectral data may reveal.

Mercury is not "pretty" but it's important. We have only 6 large rocky planetary objects in this solar system (in the geologic sense... including Moon and Io), plus small numbers of rocky sub-dwarf planets like Vesta that had active volcanism erupting onto the surface. It's a small sample and every one is important.

Posted by: Greg Hullender Aug 16 2007, 03:28 PM

Meanwhile, I just noticed that Messenger has started on "Orbit #5" and looks like it'll reach Mercury's orbit for the first time in a week or so. (August 24 is still my best guess.)

http://messenger.jhuapl.edu/whereis/index.php#current_orbit

Of course, Mercury itself won't be there yet, but that means we're just one more orbit away from the first Mercury encounter in thirty years!

--Greg

Posted by: mchan Aug 17 2007, 02:55 AM

2nd paragraph in http://messenger.jhuapl.edu/news_room/status_report_08_03_07.html alludes to Messenger orbit perihelion on Sep 1.

Posted by: Greg Hullender Aug 17 2007, 03:24 PM

Thanks! I should read these things more carefully. :-)

--Greg

Posted by: belleraphon1 Aug 17 2007, 07:37 PM

All..

Emily has posted a nice update about the MESSENGER January 14th 2008 Mercury flyby on her TPS blog.

http://www.planetary.org/blog/article/00001086/

Craig

Posted by: Greg Hullender Aug 17 2007, 09:05 PM

Very nice!

Emily: (If you're reading this.) What would be extra nice, if it's not too hard, would be to add an indication to your composite Mercury map (the one that combines Mariner 10 and Arecibo data) outlining the portion that will be imaged on the first Messenger flyby. From the looks of it, your map is centered rougly opposite the midpoint of what Messenger will be able to image, so I"m thinking it'll cover the largest blank in the Arecibo data and just about reach that flag-shaped blank in the middle of the Mariner 10 data.

Unless I have it backwords or something. :-)

--Greg

Posted by: elakdawalla Aug 17 2007, 09:13 PM

Easiest way to visualize what will be Sunlit and thus visible to MDIS is to ask the Solar System Simulator what Mercury looks like as seen from the Sun at closest approach:

http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=10&month=1&day=14&year=2008&hour=18&minute=17&rfov=2&fovmul=-1&bfov=30&porbs=1&showsc=1

Looks like roughly 40 degrees of the non-Mariner-10 hemisphere will be Sunlit, which is actually less than I had imagined. MESSENGER's outbound view will be almost entirely of the non-Mariner-10 hemisphere, but not so much of it will be Sunlit.

--Emily

Posted by: belleraphon1 Aug 17 2007, 09:53 PM

Yeah...

if you look at the flyby plot you can see that a lot of the unseen hemisphere will be in darkness. Seeing that I have waited 32 years to see this much more, I can handle waiting for the orbital mission in 2011.

Following planetary science takes great patience but the payoff is out of this world. biggrin.gif

Craig

Posted by: Greg Hullender Sep 1 2007, 06:31 PM

New Messenger update, marking the first perihelion at Mercury-distance.

http://messenger.jhuapl.edu/news_room/status_report_08_31_07.html

--Greg

Posted by: Greg Hullender Sep 1 2007, 08:49 PM

The more I look at the data, the more I think the January flyby will show us about 1/3 of the "missing" hemisphere of Mercury, then the October one will show another 1/3. The third flyby won't show us anything new, but (of course) once in orbit, we'll finally see the remaining piece.

Assuming I've got the links right this time :-) here's the trajectory of the first flyby:

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby1Files/Mercury1AboveNorthPoleFull.jpg

Sweeping across the unexplored terrain -- in the dark. Half a day later, here's the view from Messenger:

http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=1&day=15&year=2008&hour=6&minute=00&fovmul=1&rfov=2&bfov=30

Just eyeballing it, then, that's roughly 1/3 of the "blank" space.

For the October flyby, Mercury has rotated 180 degrees, so the night flight is over known terrain, but, unfortunately, so is much of the day flight.

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby2Files/Mercury2AboveNorthPoleFull.jpg

About half a day past the encounter, about 1/3 of the blank space has peeked into view, but that's about it.

http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=10&day=6&year=2008&hour=23&minute=00&fovmul=1&rfov=2&bfov=30

The third flyby, in September 2009, has about the same geometry as the second one:

http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/MercuryFlyby3Files/Mercury3AboveNorthPoleFull.jpg

But it's not identical. Looking at Mercury from Messenger about half a day later, we actually see a bit LESS of the blank area than we did on flyby #2.

http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=199&vbody=-236&month=9&day=30&year=2009&hour=17&minute=00&fovmul=1&rfov=2&bfov=30

So it looks like the first two flybys will be pretty cool, but then we'll have a 2-1/2-year wait before there's much more new info.

Still not as bad as the 34-year wait BEFORE flyby #1!

--Greg

Posted by: edstrick Sep 2 2007, 07:15 AM

it looks like flyby's 2 and 3 will provide excellent quality stereo data, as the illumination (except pretty near the terminator) looks like it should be pretty similar. Baseline between the views isn't large, but probably decent.

Posted by: AlexBlackwell Sep 12 2007, 07:32 PM

http://messenger.jhuapl.edu/news_room/status_report_09_12_07.html
MESSENGER Mission News
September 12, 2007

Posted by: cndwrld Oct 1 2007, 01:50 PM

I saw one of the principle scientists from Messenger the other day. Knowing the desires of people here, I noted the level of interest and asked how soon after the January 14 flyby some images might be released. He said that they are planning on getting the data down in two days, and should have images out shortly after that on the web site. So, expect the first public data on 16 or 17 January.

They have a big conference planned in Spring 2008. After that, more data should get released to the public.

Posted by: nprev Oct 2 2007, 04:12 AM

Nice! smile.gif Thanks, CND; definitely something to look forward to!

Posted by: NMRguy Oct 18 2007, 09:48 AM

One step closer. MESSENGER sets itself up for the January flyby (in 88 days).

http://messenger.jhuapl.edu/news_room/status_report_10_17_07.html
MESSENGER Mission News
October 17, 2007

Posted by: MahFL Oct 18 2007, 01:51 PM

Great news.

pancam.gif

Posted by: NMRguy Nov 21 2007, 11:07 PM

I still find myself forgetting how long MESSENGER must travel in order to get to orbit insertion, especially given that the first flyby is only 53 days away. (That's less than two months for those of you keeping track.) Closest approach should be within 200 km. For comparison, Mariner 10 had three flybys with closest approaches of 703 km, 48069 km, and 327 km. Fortunately, MESSENGER's three planned flybys should keep us satiated, especially given how long we have waited to get to this point.

http://messenger.jhuapl.edu/news_room/status_report_11_19_07.html
MESSENGER Mission News
November 19, 2007

Posted by: mchan Dec 5 2007, 05:53 AM

Contact made to Messenger after solar conjunction:

http://messenger.jhuapl.edu/news_room/status_report_12_03_07.html

The countdown clock to first flyby is now 40 days (and nights).

There's already enought recent posts in this thread to start a separate first flyby thread. (Hint, hint.)

Posted by: Greg Hullender Jan 2 2008, 04:30 PM

Not related to this month's flyby (not to say completely arbitrary) but according to the website, Messenger completed orbit #5 last night.

http://messenger.jhuapl.edu/whereis/index.php

In particular, we can see that the new aphelion is inside Venus' orbit. After the big changes we saw from the Earth and Venus flybys, it's surprising just how much smaller the changes from the Mercury flybys are. Even knowing how small Mercury is.

--Greg

Posted by: nprev Jan 2 2008, 06:05 PM

Noticed something else new on the "Where is MESSENGER?" page:

"Beginning in January 2008 additional Mercury surface features are displayed. These radar images, which came from the 1000-foot-diameter radar antenna at Arecibo, Puerto Rico, were provided by Professor Phillip Stooke of the University of Western Ontario."

If you look at the Mercury closeup view, you can see the mosaics (which, unfortunately, are dark right now since MESSENGER's approaching almost directly on the night side). Way to go, Phil!!!!!! smile.gif smile.gif smile.gif

Posted by: peter59 Jan 6 2008, 08:48 AM

Pleiades star cluster.


Messenger's MDIM wide angle camera - 28 September 2006.

Posted by: peter59 Jan 6 2008, 10:27 AM

.. and more


Messenger's MDIM narrow angle camera - 07 June 2007.
Image EN0089626603M

Posted by: Phil Stooke Jan 6 2008, 02:19 PM

You saw it here first, nprev!

Phil

Posted by: ugordan Jan 6 2008, 02:25 PM

QUOTE (peter59 @ Jan 6 2008, 09:48 AM) *
Pleiades star cluster.

Where did you get these images, Peter? Are they raw (as that dust ring on Venus suggests)?

P.S. The instrument's MDIS not MDIM.

Posted by: djellison Jan 6 2008, 05:28 PM

http://pds-imaging.jpl.nasa.gov/data/messenger/MDIS


 

Posted by: nprev Jan 6 2008, 05:48 PM

ohmy.gif ...<clink>...LAND HO!!!

Look at those beautiful albedo features already, esp. at the North Pole....wowowow!!!

I knew this was gonna be a good year... smile.gif

Posted by: Phil Stooke Jan 6 2008, 05:58 PM

April fool! That was the moon. Here it is modified a bit. (oh wait, it's not April)

Phil


Posted by: Paolo Jan 6 2008, 05:59 PM

unnecessary quoting removed

I fear that is ye olde Moone

Posted by: nprev Jan 6 2008, 06:09 PM

You guys sure? I was thinking that too (farside view), but when I looked it over it didn't seem right...that dark polar hood didn't look right at all.

Oh, well; if it is the Moon, then I'm Ye Olde Foole...(yeah, that's unusual for me...) rolleyes.gif

Posted by: Phil Stooke Jan 6 2008, 06:13 PM

That's no dark polar hood, that's Oceanus Procellarum. Besides, the approach view of Mercury is a narrow crescent.

Phil

Posted by: djellison Jan 6 2008, 06:14 PM

It IS the Moon - hence why I cited the PDS where the early MDIS stuff is.

Posted by: nprev Jan 6 2008, 06:22 PM

Sigh...too much anticipation...

 

Posted by: ugordan Jan 6 2008, 06:25 PM

QUOTE (djellison @ Jan 6 2008, 06:28 PM) *
http://pds-imaging.jpl.nasa.gov/data/messenger/MDIS

Wow, how long has that been lying around there???

The calibration procedure appears to be well documented (at least less messy than Cassini stuff), it'd be interesting to try and make a tool to calibrate these images. Even without calibration the images turn out nice, the MDIS WAC has a very tight PSF too. A simple filter combo with a color tweak gives this:
http://i108.photobucket.com/albums/n15/ugordan/earth.jpg

Posted by: Phil Stooke Jan 6 2008, 06:52 PM

I don't have time to search at the moment - is this the best moon view from this set?

Phil

Posted by: ugordan Jan 6 2008, 07:04 PM

I think images EN0031264914M.IMG and EN0031264925M.IMG are the best Moon images, the latter was taken almost at the same time as the first but is slightly blurrier for some reason.

Here's EN0031264914M.IMG cropped and sharpened:


Posted by: JRehling Jan 6 2008, 11:17 PM

Yep, Mare Orientale is near center, Procellarum is at top, the dark-but-not-maria patch at bottom is the Aiken-South Pole basin, and the south pole is near the middle of the terminator.

Mercury is much less contrasty than the Moon. Although it's a little more segregated than Mariner 10 images suggest simply because the border between the inbound view and the outbound view happened to fall roughly on the border between an area with smooth plains and an area of cratered highlands. Either Mariner 10 image individually shows less diversity than other hemispheric views of Mercury are likely to.

Posted by: tedstryk Jan 6 2008, 11:54 PM

Here is my take on the image.


Posted by: tedstryk Jan 7 2008, 03:53 AM

Wow, it really is a good camera. Here is the distant view taken before the first Venus flyby.


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