MESSENGER ARRIVES, Mercury Orbit Insertion Options

[Astro0]

Less than 20 hours now until the MESSENGER spacecraft fires its engine to enter orbit at Mercury.

Live Webcast March 17th – broadcast starts at 0030 UTC.

Follow the progress: http://messenger.jhuapl.edu/mer_orbit.html.
There will be commentary on the mission, real-time coverage of the maneuver, animation of what the spacecraft is doing, a view of the carrier’s Doppler as they receive it, and live video from MESSENGER Mission Operations.

Remember that the Canberra DSN is providing two-way communication with MESSENGER
We'll be using both DSS43 (70-metre) and DSS34 (34-metre) antennas.

Good luck to the team at Johns Hopkins University Applied Physics Laboratory (APL).

[nprev]

Aim your dishes well, Astro0, and may no passing birds cause the loss of a single bit!

Very exciting time. "Firsts" just never get old. Best of luck to the entire Messenger team, including of course the FAR too-often unappreciated people who keep the DSN up & running!

[Explorer1]

Mercury is a disk already in the 'where is MESSENGER now' view. It's getting exciting already...

[dmuller]

7.9 billion kilometers just to get there. That makes it one of the longest distances flown by a spacecraft:
(http://www.dmuller.net/spaceflight/realstats.php?stats=flown).

Anyway, my standard realtime simulation is now updated for MOI:
http://www.dmuller.net/messenger

[Guest_Sunspot_*]

I can't get "Mars" Orbit Insertion (MOI) out of my head, rather than Mercury Orbit Insertion (MOI) !!!!

[Decepticon]

Is there a way to listen to MOI via my cell phone?

I would love to watch but I'm working at that time.

Audio would be great!

Any help?

[akuo]

Is it so that there is no following of the MOI on any Nasa-TV channels?

Answering my own post: looks like that the Nasa-TV schedule has been updated and Messenger will be followed on Nasa-TV from 19:55 ESST onwards:
7:55 p.m. - MESSENGER: Mercury Orbit Insertion Coverage from APL - APL/HQ (ALL Channels)

[Gsnorgathon]

Since this mission's run by JHUAPL and not JPL, do we still need to get our dry-roasted peanuts for MOI?

[B Bernatchez]

7.9 billion kilometers just to get there. That makes it one of the longest distances flown by a spacecraft:
(http://www.dmuller.net/spaceflight/realstats.php?stats=flown).

Anyway, my standard realtime simulation is now updated for MOI:
http://www.dmuller.net/messenger

Shouldn't the last item on that list read "Start of first mission extension"?

[djellison]

It's in Eyes on the Solar System as well - complete with the change of attitude, and the engine burn http://go.usa.gov/4u1

(shortcut works great in Firefox/Safari/IE - but there's a bug that we need to sort out about Chrome)

[volcanopele]

Good to know! I tried getting MESSENGER to work in Celestia with the spice kernels available from the PDS, but it keeps balking

[MahFL]

Hello everyone.
Pretty exciting !

[ZLD]

It's in Eyes on the Solar System as well

Yes and Mercury is getting quite large on the screen. Eyes On The Solar System is definitely a great tool!

[MarkG]

I like the Irish music in the background of some of the on-line presentations. Nice!

Being part of this exploration history never gets old...

[Explorer1]

Start of burn confirmed, looking at Doppler.

[Bjorn Jonsson]

"Thruster firing, everything looking just perfect"

[Astro0]

Gotta say that I'm enjoying the JHU/APL broadcast. Very slick. Live audience adds a nice element.

[DFinfrock]

Emily has a great Twitter feed going, if you can't view the Webcast. Follow her at @elakdalla.

ADMIN: http://twitter.com/elakdawalla

[Hungry4info]

MESSENGER is in orbit of Mercury now.

[Hungry4info]

End of main burn, tweaking now.

Edit: Lots of clapping, handshakes, looks like everything went just perfectly! Waiting on data from spacecraft to confirm.

Edit2: High rate telemetry is being received. We know now the burn did last as long as expected.

Edit3: Official confirmation of successful MOI burn. Made the target to within 0.5-sigma.

[belleraphon1]

unmanned spacecraft in orbit.. firsts..

1966 Luna 10 Moon

1971 Mariner 9 Mars

1975 Venera 8 Venus Venera 9 was the first Venus orbiter. Venera 8 was a lander with a flyby bus.

1995 Galileo Jupiter

2004 Cassini Saturn

2011 Messenger Mercury

Lived through all of them.... HOW SWEET IT IS!

i ate peanuts

Congrats team!

[pjam]

Messenger is confirmed to be in orbit around Mercury -Hooray!!
...Now the serious visit begins!
-pjam

[belleraphon1]

And... of course...

Sputnik 1957 Earth... the shot that started it all... yeah Earth is a planet.

Glorious 54 years... I was 4 that year.

Craig

[tasp]

Was super busy all day today, and just now came to this thread, and with a rising sense of anticipation, read all the posts.

Whew! And attaboys and 'ham sammiches' to everyone!


I did go out the other night to see Mercury and Jupiter after sunset, and was hoping all was well.

[NMRguy]

At long last, MESSENGER enters orbit! Congrats to the team and let the science begin (following check out, of course)!

[Paolo]

unmanned spacecraft in orbit.. firsts..

you forgot poor Eros...

[Explorer1]

And Itokawa! (if it counts as 'orbiting' at all....)

[Paolo]

Itokawa was too small. Hayabusa didn't do much orbiting, only station keeping in solar orbit

[CAP-Team]

Congrats! Great to hear that it worked!

@Volcanopele you can find good spice kernels on the NAIF FTP site in the PDS folder for use in Celestia, including the main mission period.

[Stu]

Fantastic news! And if you haven't seen it already, Emily has made an absolutely gorgeous pic for her blog, showing Mercury's size compared to other familiar bodies in the solar system...

http://www.planetary.org/blog/article/00002965

[craigmcg]

Nice article in the NY Times

http://www.nytimes.com/aponline/2011/03/17...rss&emc=rss

[ngunn]

Emily has made an absolutely gorgeous pic for her blog, showing Mercury's size compared to other familiar bodies in the solar system...

Indeed, a very nice comparison. But we already know of two other bodies in that size range, namely Pluto and Eris, making a total of 10.

[Stu]

True, but we haven't got very good images of those to use, tho.

[belleraphon1]

unmanned spacecraft in orbit...

how did I miss the worldlets????? Eros and possibly Itokawa.... must be my age... and the beer.
Thanks for the corrections folks.

The Eyes on the Solar System site had a terrific simulation.... really felt like I was riding along as I listened to the webcast.
Terrific experience...

Kudos all .....

Craig

[brellis]

Emily's survey is great! I felt proud to recognize each orb, like a bunch of old friends.

[ElkGroveDan]

like a bunch of old friends.

I used to have friends like that; remote, lonely, frigid, two-faced, endlessly going in circles, still showing the obvious scars that impacted them long ago. Sure there was always at least one hot one, but she'd usually be prone to eruptions. Since then I found UMSF and a whole new universe of friends.

[Stu]

[machi]

Congratulation to the MESSENGER team!

I used to have friends like that; remote, lonely, frigid, two-faced, endlessly going in circles, still showing the obvious scars that impacted them long ago. Sure there was always at least one hot one, but she'd usually be prone to eruptions. Since then I found UMSF and a whole new universe of friends.

[Stu]

VERY proud that the MESSENGER team used a new poem I wrote for them, marking MOI...

http://messenger.jhuapl.edu/mer_orbit.html

(bottom right)

[gndonald]

Congratulations to NASA!

I'm eagerly awaiting the first light photo from orbit...

[elakdawalla]

Fantastic news! And if you haven't seen it already, Emily has made an absolutely gorgeous pic for her blog, showing Mercury's size compared to other familiar bodies in the solar system...
http://www.planetary.org/blog/article/00002965

I'm glad you liked that; I'm pleased with how it turned out, though of course it looks good mostly because of Ted's excellent processing work. It's wonderful what matching phase angles and lighting directions will do to improve the feel of a montage. I spent half an hour discussing that image with my girls' babysitter last night -- a fun conversation

Indeed, a very nice comparison. But we already know of two other bodies in that size range, namely Pluto and Eris, making a total of 10.

As Stu said, we don't have images of those! --but in the text and caption I did make an error about how these were all the things in the solar system between 2000 and 6000 km across -- should've stuck with 2500-6000 and I'd've been correct; or just left Triton off and left it at 3000-6000. I have a massive cheat sheet above my desk that I use to do quick size comparisons, but I don't have the KBOs on there yet because I'm still working on hunting down the best estimates of their sizes. I have got to finish that project.

Emily's survey is great! I felt proud to recognize each orb, like a bunch of old friends.

Me too The challenge for us uber-geeks is to know just from looking at them which spacecraft was responsible for each image.

[tedstryk]

-but in the text and caption I did make an error about how these were all the things in the solar system between 2000 and 6000 km across -- should've stuck with 2500-6000 and I'd've been correct; or just left Triton off and left it at 3000-6000.

It isn't an error - all are in that range.

[nprev]

Belated congrats after a long night of work to the MESSENGER team for their own many, many long nights of work that resulted in not only a spectacular success but a truly historical achievement.

[Drkskywxlt]

I was in the studio audience last night and I want to give kudos to APL for putting on a very entertaining and informative show. Pretty amazing that by July we'll have spacecraft orbiting 8 solar system bodies (Sun, Mercury, Venus, Earth, Moon, Mars, Vesta and Saturn). Too bad MESSENGER probably won't be around in 2016 when Juno arrives at Jupiter to make it 9!

[nprev]

Me too The challenge for us uber-geeks is to know just from looking at them which spacecraft was responsible for each image.

A challenge indeed, considering Ted's great skill at reprocessing data from older missions!

Okay, I'll take a shot, from left to right (the last one is a gimmie, though):

Messenger, Clementine, Cassini, Galileo, Galileo, Voyager 1, Cassini, Voyager 2.

<braces for humiliation>...

(And congratulations to Stu for his terrific poem posted on Messenger's most special day.... )

[elakdawalla]

You got half right, Nick!

[tedstryk]

The moon looks like an oddly colored earth-based view, Titan is clearly from Cassini. I will ignore the others, since that really wouldn't be fair.

[SFJCody]

The Mercury view is Mariner 10 - you can see the Caloris basin on the terminator.

[Guest_Oersted_*]

Congrats to the Messenger team and their new in-house poet, Stu!

[brellis]

"The challenge for us uber-geeks is to know just from looking at them which spacecraft was responsible for each image. "

share?!

[elakdawalla]

Mercury: Mariner 10; Moon, an Earth-based photographer (sorry, that was a trick one); the Galileans all from Galileo; Titan from Cassini; Triton from Voyager 2.

See http://planetimages.blogspot.com/2009/09/f...om-galileo.html
and
http://www.lpod.org/coppermine/displayimag...m=37&pos=97

[eoincampbell]

Successfully named orbs, but camera names - not...hopefully,a few more years of UMSF, PS and AmateurSpaceImages etc., should take good care of that!
Congrats to the MESSENGER team, looking forward to the images.

[JohnVV]

a few days old
I have been ill

Good to know! I tried getting MESSENGER to work in Celestia with the spice kernels available from the PDS, but it keeps balking

same here there is some "odd" thing going on
i has been a few months but right now celestia thinks it is out by mars

right now i am thinkint to just skip the first 3 trips around and use only the CURRENT and forward
then fix it .
- quote from "CAP-Team"

@Volcanopele you can find good spice kernels on the NAIF FTP site in the PDS folder for use in Celestia, including the main mission period.

for those here that do not know that address
ftp://naif.jpl.nasa.gov/pub/naif/pds/data/

[Greg Hullender]

The Messenger site has updated the "Where is Messenger" page with seven new views, including the Messenger ground track. Check it out.

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

--Greg

[J.J.]

Though I'm a little late to the thread, I'd like to congratulate everyone involved on a job well-done.

[Julius]

congrats to the messenger team..a job well done!

[tanjent]

I can't load Greg's "where is Messenger" link. Maybe the site is taking a well-deserved weekend's rest along with the personnel?
In the temporary absence of photographic evidence of Messenger's arrival, we'll have to stave off our hunger by consuming a week's worth of sims.
Will try again Monday.

[brellis]

My eyes are getting thirsty for pics!!

[Explorer1]

The link is fine on my end.

[tedstryk]

It isn't going to take pictures until March 29, so don't hold your breath.

[Greg Hullender]

I can't load Greg's "where is Messenger" link.

Seems to be working now: http://messenger.jhuapl.edu/whereis/index.php

Perhaps they do site maintenance on Sundays.


--Greg

[hendric]

Too bad MESSENGER probably won't be around in 2016 when Juno arrives at Jupiter to make it 9!

Ah, but May 2014 will have Rosetta orbiting Comet 67P/Churyumov-Gerasimenko (can we start calling it C-G now? ), so if it made it to 2014, it would make operating spacecraft around 10 solar system objects!

[tedstryk]

(can we start calling it C-G now?

Nope, and you have to say it fast five times every time you mention it.

[Stu]

Really wanted to get this pic to mark MESSENGER's arrival, so tonight I hiked up to the castle even with my knackered knee...!

Four days before MESSENGER starts photographing Mercury - Mercury seen from Kendal:

http://twitpic.com/4d8896

[bkellysky]

Nice shot!
It's good to get a wide-angle view (like yours) before getting the close-up (MESSENGER's).
P.S., if anyone hasn't seen Mercury in the evening sky - low in the west 30 minutes after sunset - do it now as Mercury is fading fast (from Earth's point of view).
bob
http://bkellysky.wordpress.com/

[Stu]

Thanks Even wider angle shot...

http://twitpic.com/4d88na

(Mercury's a bit hard to see - you need to enlarge the image by putting your cursor at the pic's top right to bring up an "enlarge" optionm then you'll see Mercury between the tower and tree. You might need to squint, but it's there.

Honest.

[bkellysky]

*Sigh*
That's wonderful!
My photos were taken from a high school football field's bleachers.
Your shot was worth the climb!

[Holder of the Tw...]

Everything seems to be going okay so far.

Spaceflight Now Link

"Engineers switched on six of MESSENGER's seven science instruments Wednesday to start commissioning and calibrations ..."

[Greg Hullender]

First pics tomorrow. Will anyone attend the press conference?

http://messenger.jhuapl.edu/news_room/details.php?id=164

[Astro0]

It's a 'teleconference' so any media only need to phone-in.

Plus anyone can listen in via the News Audio Stream.

[nprev]

IIRC, some of the first images will be of a previously unobserved region near the North Pole?

[elakdawalla]

I *think* Louise said south pole. It's gonna be one of the poles though. I'll be phoning in for the telecon. If anybody thinks of a great question to ask, post here or Tweet me

[nprev]

Well, not a 'great' question, but what is the expected resolution of the first images, and what other instruments will be acquiring data?

[ugordan]

South pole it is.
http://messenger.jhuapl.edu/gallery/scienc...mp;image_id=429

[Anders]

If anybody thinks of a great question to ask, post here or Tweet me

I am curious about the orbital period of the MESSENGER spacecraft. Is it exactly 12 hours? If so, how was it chosen?

[MahFL]

I am curious about the orbital period of the MESSENGER spacecraft. Is it exactly 12 hours? If so, how was it chosen?

"The MESSENGER team designed the orbit to optimize the scientific yield of the mission and data transfer to Earth, while addressing thermal environment concerns.".

MESSENGER spends most of the time away from the surface to transmit data back to earth, and not to overheat due to reflected heat.

[Holder of the Tw...]

"Finnegan told Spaceflight Now the spacecraft is in an orbit with a closest approach 128.5 miles above Mercury's surface and a high point of 9,482.7 miles. The orbit is inclined 82.5 degrees to Mercury's equator and it takes MESSENGER more than 12 hours to complete one circuit of the planet, according to Doppler tracking data."

So it's more than twelve hours, but they don't say how much more.

[Anders]

So it's more than twelve hours, but they don't say how much more.

Thank You,
I got the impression that it was exactly 12 hours. That would have been an interesting trade-off.

[Phil Stooke]

Twelve hours period, with a major data downlink every other orbit, would simplify operations by having the same DSN coverage each day.

From the mission design page:

"After MESSENGER arrives in the primary science orbit, small forces, such solar radiation pressure – the force exerted by sunlight - slowly change the spacecraft's orbit. Although these small forces have little effect on MESSENGER's 12-hour orbit period, they can increase the spacecraft's minimum altitude, orbit inclination, and latitude of the surface point below MESSENGER's minimum altitude. Left uncorrected, the increase in the spacecraft's minimum altitude would prevent satisfactory completion of certain science goals.

To keep this minimum altitude below 500 kilometers (310 miles), propulsive maneuvers must occur in pairs once every Mercury year - every 88 days. The first maneuver in each pair increases the orbit period to 12 hours, 15 minutes by speeding up the spacecraft at its closest distance from Mercury. Two-and-a-half orbits later a maneuver at the farthest distance from Mercury slows the spacecraft just enough to adjust the orbit period back to 12 hours and return the minimum altitude to 200 kilometers (124 miles). Because the sunshade must protect the main part of the spacecraft from direct sunlight during propulsive maneuvers, the timing of these maneuvers is limited to a few days when Mercury is near the same point in its orbit as it was at Mercury orbit insertion."

So the current period might not be exactly 12 hours but that's immaterial, the intention is to keep adjusting it to stay around 12 hours all the time (and the correct altitude etc.).

Phil

[ugordan]

"Finnegan told Spaceflight Now the spacecraft is in an orbit with a closest approach 128.5 miles above Mercury's surface and a high point of 9,482.7 miles.

Those orbital parameters translate to 12 hours 4 minutes period if I got it right. You can never tell with "miles"...

[Hungry4info]

From here

Attached thumbnail(s)

 

[charborob]

Messenger took 363 images after that first one. More images to be posted tomorrow at 2 pm EDT.

[Bjorn Jonsson]

The image is centered at approximately 15°E and 55°S. This is a major improvement over earlier imaging coverage in this area and of course there are going to be narrow angle images as well. At a quick glance nothing that looks especially interesting. There are fairly strong contrast/brightness variations associated with some of the craters. Many scarps. And there is an interesting looking crater plus some associated features at (280,255).

[ugordan]

Looks good, nice to see the WAC behaving as if nothing happened.

[volcanopele]

Here is the image laid on top of the released footprint map. The blue outline is the area that was blank on the map to this point. The blue dot is the south pole.

Attached thumbnail(s)

 

[Anders]

Twelve hours period, with a major data downlink every other orbit, would simplify operations by having the same DSN coverage each day.

Interesting point about DSN, I didn't thought about that.

[Phil Stooke]

Very rough fit of the image to a colorized version of the pre-orbit mosaic, south polar view. (only adding the bit which improves on the previous coverage)

Phil

[brellis]

I read an article saying thrusters have to be fired every few months to keep MESSENGER from floating into a higher orbit by the Sun's gravity. I don't get that, since it's in a polar orbit.

Oh, wait -- the Sun is ALWAYS tugging on things, and at the proximity of Mercury, it gets taken into account throughout the orbit, on a scale similar to instances where the ISS fires thrusters to stay at altitude versus miniscule atmospheric drag. Okay, I get that.

When it doesn't have any fuel left, will it get sucked into the Sun?

LOL! The mission science is just beginning, I'm already wondering what's going to happen to our intrepid spacecraft when it runs out of fuel!

[eoincampbell]

It really is astounding science, all hail MESSENGER team,
cue: heavy orchestral sounds for MESSENGER images

[Hungry4info]

When it doesn't have any fuel left, will it get sucked into the Sun?

The plan is for an impact on Mercury. But hypothetically, if they were to refrain from adjusting the orbit, and if MESSENGER left Mercury's hill sphere, it would orbit the sun.

[HughFromAlice]

What a great achievement!!!

First historic pic from orbit - and since I always love to experiment and bring out as much detail as possible in photos just for my own interest - I did a false colour (+ a few other things) version during lunch which seemed worth posting. So here it is!! Haven't been here for a while but good to see everyone's passion and skills again :-)

Hi res 6 mb!! version at https://picasaweb.google.com/10220631534056...730326334840018

[Explorer1]

There's a link to the teleconference on this page now:
http://www.nasa.gov/news/media/newsaudio/index.html

[Hungry4info]

Several new images have appeared here.


As for questions: where are the raw images posted?

[elakdawalla]

No raw images for this mission, but their first delivery to the PDS will be just 6 months after orbit insertion, probably including 2 months worth of data.

[nprev]

First color image released:

http://messenger.jhuapl.edu/gallery/scienc...r.coreg.rgb.png


Hopefully this is an approximation of 'natural'; if so, we're in for a real treat!

[ZLD]

I've actually been wondering, are the filters on the WAC as narrow as the graph below portrays? If so, how close to 'natural' is actually possible for the images?

[djellison]

I see no reason why the chart would be wrong. The aim is not to take 'natural' color photographs. The aim is to do science. Much like with MER and other spacecraft, you take those science filters and approximate a true color view using algorithms.

[Drkskywxlt]

Hopefully this is an approximation of 'natural'; if so, we're in for a real treat!

I believe it's enhanced with the IR filters to bring out the blue/yellow shades. So, I don't believe it's what your eye would see if you were in MESSENGER's position.

Still a nice pic though!

[tedstryk]

It is what you might see if your eyes were properly designed to study the surface composition of Mercury.

[Phil Stooke]

New pic!

Phil

http://messenger.jhuapl.edu/gallery/scienc...mp;image_id=442