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Unmanned Spaceflight.com > Inner Solar System and the Sun > Mercury > Messenger
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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
QUOTE
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"
QUOTE
@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. smile.gif
Julius
huh.gif 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!! smile.gif
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
QUOTE (tanjent @ Mar 20 2011, 08:09 AM) *
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
QUOTE (Drkskywxlt @ Mar 18 2011, 02:10 PM) *
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? smile.gif ), so if it made it to 2014, it would make operating spacecraft around 10 solar system objects!
tedstryk
QUOTE (hendric @ Mar 21 2011, 06:41 PM) *
(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 smile.gif 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. laugh.gif
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 Two Leashes
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 smile.gif
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
QUOTE (elakdawalla @ Mar 29 2011, 06:35 AM) *
If anybody thinks of a great question to ask, post here or Tweet me smile.gif

I am curious about the orbital period of the MESSENGER spacecraft. Is it exactly 12 hours? If so, how was it chosen?
MahFL
QUOTE (Anders @ Mar 29 2011, 10:42 AM) *
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 Two Leashes
"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
QUOTE (Holder of the Two Leashes @ Mar 29 2011, 03:59 PM) *
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
QUOTE (Holder of the Two Leashes @ Mar 29 2011, 03:59 PM) *
"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

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 15E and 55S. 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. smile.gif
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.
Anders
QUOTE (Phil Stooke @ Mar 29 2011, 06:41 PM) *
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

Click to view attachment
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! sad.gif
eoincampbell
It really is astounding science, all hail MESSENGER team,
cue: heavy orchestral sounds for MESSENGER images smile.gif
Hungry4info
QUOTE (brellis @ Mar 29 2011, 09:56 PM) *
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

Click to view attachment
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! smile.gif
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?
Click to view attachment
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
QUOTE (nprev @ Mar 31 2011, 01:05 AM) *
Hopefully this is an approximation of 'natural'; if so, we're in for a real treat! smile.gif


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. smile.gif
Phil Stooke
New pic!

Phil

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