MESSENGER News Thread, news, updates and discussion Options

[paxdan]

Launched on August 3rd 2004, NASA's MESSENGER will become the first spacecraft to orbit Mercury.

News and updates are availbale via Johns Hopkins University MESSENGER website and the Kennedy Space Center's MESSENGER website.

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 status report from JHU. Extensive JHU FAQs page here.

[Buck Galaxy]

Launched on August 3rd 2004, NASA's MESSENGER will become the first spacecraft to orbit Mercury.

News and updates are availbale via Johns Hopkins University MESSENGER website and the Kennedy Space Center's MESSENGER website.

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 status report from JHU. Extensive JHU FAQs page here.

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.

[Jeff7]

Launched on August 3rd 2004, NASA's MESSENGER will become the first spacecraft to orbit Mercury.

News and updates are availbale via Johns Hopkins University MESSENGER website and the Kennedy Space Center's MESSENGER website.

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 status report from JHU. Extensive JHU FAQs page here.

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. 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.


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

Oh, seems NASA anticipated this question. Link. 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.

[tedstryk]

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.

[MiniTES]

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

[JRehling]

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.

[tedstryk]

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.

[edstrick]

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...

[Bob Shaw]

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).

[JRehling]

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.

[JRehling]

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.)

[Bob Shaw]

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...

[Chmee]

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!

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

[RNeuhaus]

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?

[paxdan]

Earth from MESSENGER at 29.6 million km

[Guest_Sunspot_*]

http://messenger.jhuapl.edu/news_room/pres...se_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."

[um3k]

No focusing problems on this baby!

[lyford]

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?

[paxdan]

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

[Guest_BruceMoomaw_*]

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.

[Bob Shaw]

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

[JRehling]

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.

[Buck Galaxy]

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?

[Phil Stooke]

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

[Guest_BruceMoomaw_*]

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).

[Bob Shaw]

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!).

[Toma B]

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

[Guest_BruceMoomaw_*]

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.)

[Guest_BruceMoomaw_*]

"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".

[gpurcell]

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?

[Guest_BruceMoomaw_*]

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.

[JRehling]

"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.

[djellison]

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

Doug

[Toma B]

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

[djellison]

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

[Bjorn Jonsson]

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

[JRehling]

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).

[Guest_Sunspot_*]

http://messenger.jhuapl.edu/news_room/pres...se_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.

[dilo]

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?

[Guest_Myran_*]

Either reorientation or its in a constant slow rotation.

[djf]

Just noticed this: http://planetary.org/news/2005/messenger_f...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.

[deglr6328]

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

[hendric]

We do have one hell of a beautiful planet.

Anyone know of rotation movies of other planets?

[JRehling]

We do have one hell of a beautiful planet.

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.

[tedstryk]

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.

[hendric]

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

[djellison]

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


Doug

[Stephen]

The MESSENGER team has posted a quite amazing "movie" 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

[MizarKey]

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

[Guest_BruceMoomaw_*]

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

[dvandorn]

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

[djellison]

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

[tedstryk]

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.

[Guest_BruceMoomaw_*]

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

[tedstryk]

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.

[Guest_BruceMoomaw_*]

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.

[um3k]

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!)

[JRehling]

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..._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

[um3k]

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

[JRehling]

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

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.

[The Messenger]

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

[um3k]

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).

[odave]

From the Messenger Website FAQ:

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...

[Guest_BruceMoomaw_*]

"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.

[dvandorn]

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

[Guest_BruceMoomaw_*]

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.

[edstrick]

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.

[Bob Shaw]

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

[Guest_BruceMoomaw_*]

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.

[Rakhir]

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/stat...t_11_11_05.html

Rakhir

[antoniseb]

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.

[tedstryk]

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/stat...t_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.

[Guest_BruceMoomaw_*]

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.)

[tedstryk]

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?

[JRehling]

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" 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.

[tasp]

The main thruster is apparently "this". It will be fired for the first time in this manuever. If "this"    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?

[JRehling]

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!

[dvandorn]

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

[tasp]

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.

[Guest_BruceMoomaw_*]

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.

[Guest_BruceMoomaw_*]

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...

[ljk4-1]

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?

[Guest_AlexBlackwell_*]

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.

[Guest_AlexBlackwell_*]

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

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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.


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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/.

[dilo]

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...

[angel1801]

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.

[Guest_AlexBlackwell_*]

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.

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..."

[ugordan]

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?

[Guest_Sunspot_*]

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......

[Guest_AlexBlackwell_*]

I'm lost.

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

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.

This post has been edited by AlexBlackwell: Mar 23 2006, 05:17 PM

[dilo]

A flyby mosaic (only 7 images)

Attached thumbnail(s)

 

[Guest_AlexBlackwell_*]

MESSENGER Passes the Billion-Mile Mark!
MESSENGER Status Report
March 24, 2006

[antoniseb]

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.

[abalone]

MESSENGER Passes the Billion-Mile Mark!
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!!

[RNeuhaus]

A new update news from Messenger status:

Mercury Messenger Probe Flips Sunshade Towards The Sun

http://www.spacedaily.com/reports/Mercury_...ds_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

[Guest_AlexBlackwell_*]

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 MESSENGER Publications page now has links to several of the references.

[Guest_AlexBlackwell_*]

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/ME...enusFlyby1.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/pressrele...006/060623b.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.

[Guest_AlexBlackwell_*]

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.

[Guest_AlexBlackwell_*]

MESSENGER Tweaks Its Route to Mercury
MESSENGER Mission News
September 15, 2006

[climber]

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