Here's hoping for a safe orbital entry...

Powerful Orbiting Camera Will Send Its First View of Mars to UA Soon
http://uanews.org/cgi-bin/WebObjects/UANew...ArticleID=12261

"HiRISE scientists will power the HiRISE camera the week of March 20. It will begin taking pictures 18 hours later, and it will take pictures during two orbits. NASA Jet Propulsion Laboratory mission specialists will decide exactly which orbits will be HiRISE imaging orbits after Mars orbit insertion on March 10.

These will be the camera's only photos for the next six months because it will be turned off while the spacecraft "aerobrakes." This involves dipping repeatedly into the upper atmosphere to scrub off speed and drop into successively more circular orbits.

The camera will take pictures of the middle latitudes of the southern hemisphere, a region where many geologically recent gullies have been seen, gullies possibly carved by water. Researchers won't know the exact area they'll photograph until the spacecraft is safely captured into orbit around Mars.

The camera's first images will be taken when the MRO is flying between about 2,500 miles and 600 miles (4,000 km and 1,000 km) above the planet. After aerobraking, the camera will fly just outside the planet's atmosphere at only 190 miles (about 300 km) above the surface."

March 20th? These plans are evidently in flux. The press release on the MRO website states:



I suppose the new plan was covered in the press conference yesterday?

There's a conf at 1800 UT tonight, I'll listen in and see if anything's mentioned.

Doug

Oh, I was thinking the conference was yesterday... thanks.

I've been watching the MOI from work today (and don't you know it, everything goes wrong here when the broadcast is in full swing ). Anyway, I suppose the next big thing to look for is this test of the three cameras, eh?

I didn't notice any more info about the exact date on the conference thread. Any news? I'm itching to see a HiRise image.

Joe, do you have a link to the press release that you quoted?

----crabbsaline

PS: This Arizona Republic article shows the date as post-19th:



edit: Never mind, Joe. I found the source. (page 28).

A pity JPL won't try and get a shot of opportinty of negected Deimos.

The current schedule shows the imaging happening on 3/22, but I'm not sure when the downlinking of the images will be finished, and there's still some schedule uncertainty depending on how the transition into orbital operations proceeds. It'll probably be better nailed down by the end of this week.

Steve G said "A pity JPL won't try and get a shot of opportinty of negected Deimos."

Good point. Many folks don't appreciate how neglected it is. Our imaging coverage is very limited. The best images, which are very few, are all of one side. Most of the trailing side is seen in only one (yes, one... so not even stereo) high phase image. Anything new would be great. The highest priority ought to be the trailing side under different illumination conditions, to show topography better. That would allow a study of the relationship between the largest array of bright streaks and the otherwise completely unknown topography.

MOC took nice images of Phobos early in the mission during several close passes. After that I assumed there would be no more, but I was pleased to see an image taken later when Phobos was just over the limb of Mars. If that feat could be duplicated for Deimos we could get significant new information, despite the low resolution. And certainly a glimpse from MRO would be a real treat.

Of course, JPL is not in charge of HIRISE. Our buddies in Tucson would have to take care of that.

Phil

We've thought about doing Deimos imaging with MOC, but the resolution possible from the mapping orbit is pretty bad; about 82 m/pxl at the closest approaches, and poorer that that for the ones where we wouldn't be shooting into the sun. But we can think about it again; if you can work out when and where we would improve the coverage over Viking that would help to sell it.

Do you mean with MRO? Not sure if the latest kernels are accurate, but using
spk_ab_ref060307_060310_060706_p-v1.bsp gives a closest approach to Deimos of 10,083 km on March 13 at 18:48 UTC. Something like 7/10000 = 700 uradians or 700 pixels across--10 m/pixel. How would that compare to Viking?

No. It's a lot easier for us to do this sort of stuff with MGS than it'll be with MRO; during aerobraking they're not going to perform imaging slews. (It was only the long suspension of aerobraking on MGS due to the SA damper problem that allowed the first MOC Phobos images to be done.) And I suspect it'll be a long time after MRO has gotten into mapping before they start doing stuff like slewing to image the moons.

Mariner 9 never saw the trailing side of Deimos. Viking saw it in only one single image (with a second over-exposed). Absolutely anything that shows the trailing side will give new information. If several views could be obtained at different Ls the varying terminator positions and relief seen with different lighting would really help enlarge our understanding of Deimos, especially the interaction between the relief and the bright streaks. There would be no value in seeing the leading side. Mars Express has a few lower resolution images of the leading side so far, but MOC should be better.

Phil

With MGS's orbit being so tight around Mars compared to Deimos' orbit, seems like MGS would see not much more than the Mars-facing side of Deimos, no? For the trailing side that would place 90E-180E out of sight. Or more accurately the MGS subpoint might get to 6E best case. Here's one view coming up in a few days (15MAR2006 15:00 UTC), with the subpoint at 5E, range 22863 km, using your cylindrical mosaic with the trailing side tinted red, modeled as a tri-axial ellipsoid:



At that range the narrow angle resolution would be 77 m/pixel.

Very nice! But the real 3-D shape would allow a better view than the ellipsoid suggests, as that side appears to be flattened more than this triaxial ellipsoid. And the true shape of the limb at right is unknown. That if nothing else would be a new input to the shape model. This image shows nicely where the cut-off of high resolution imaging falls, not far east of the prime meridian. Then we have a strip about 40 degrees wide of low quality imaging based on just two very early Viking images, and then the outer strip based on only one high phase view. With good lighting we would still learn something new about this region.

By a happy coincidence your simulation date of 15 March is my birthday. I'll take this as a birthday card!

Phil

Enceladus demonstrates that great things can come in little packages.

What can Mars Express do on Deimos in terms of coverage of the trailing hemisphere? Also, might Rosetta be able to help with this?

The only opportunity to image Deimos (or Phobus) would be during the initial orbit phase of the mission. Those long looping orbits, I'm sure, would have presented with a few chances for some good shots. However, it's not a priority, obviously, which is a shame.




Dawn is planning a Mars flyby, isn't it. Oh, that's right, it was cancelled. Apparently Ceres and Vesta, each completely unique in the Solar System, aren't important enough to keep the mission aflaot.

Sorry for the sarcasm, there should have been dedicated asteroid missions decades ago.

Alas, since a slew is involved it'll take a bit longer to get this planned, but it seems like a worthwhile image, so I'll see if we can get it taken.

To "Investigate the global chemical heterogeneity on Phobos and Deimos" is a stated goal of the flyby, and I saw on a sequencing document that coverage on approach should occur, so there may be at least low resolution coverage. However, the documents hadn't been updated for the new trajectory, so exactly how it will play out isn't answered.

Bless you, my child. (Has anyone come up with a theoretical explanation for why Deimos and Phobos have such radically different-looking surfaces?)

Bruce said "Bless you, my child" - is that another birthday greeting?

The best explanation for the difference between P and D would appear to be that of Peter Thomas and colleagues at Cornell: that Deimos is basically completely covered with a thick layer of ejecta from a very large impact. No large crater? Yes, there is. The entire south polar region is saddle-shaped, and is interpreted by Thomas et al. as a crater with a diameter about the same as the diameter of Deimos itself. I happen to agree with this. Phobos lacks anything of this magnitude.

This is a good time to demolish the old idea that such a large impact would destroy the target. Modelling of such impacts does not support this old idea. This also applies to Mimas, where in another thread Bob Shaw mentioned the Voyager-era idea that the Herschel impact 'nearly destroyed' Mimas. It was nowhere near doing that. To destroy a body, the shock front from the point of impact has to completely engulf the target body while still having enough energy to dissipate the fragments. Herschel stopped growing when its shock wave energy/unit area dropped below the point at which it could throw out fragments, obviously long before the wave passed through Mimas entirely. Ditto Stickney on Phobos.

mcaplinger - no, the birthday card was jmknapp's picture! I know the image would take much longer to acquire. Oh, and say Hi to Ken from me!

Ted Stryk asked about Mars Express. I've posted a couple of the SR images elsewhere here. The resolution is probably a bit worse than MOC, but with the proper lighting it could add to the stock of images of that side. So far, though, all MEX images that I've seen show mainly the leading side.

Phil

It's true that the idea that Herschel Crater was something outlandish now seems slightly quaint. There are relatively bigger impact basins on Iapetus, and megacraters on almost every moon of Saturn, including little Hyperion.

By the way, does anybody know if Herschel Crater is named after William (who discovered Mimas) or John (who named it)?

Am I right that you're referring to the planned Rosetta flyby? Google turned up that phrase on an ESA page describing the OSIRIS instrument flying on Rosetta. Orbiter Instruments: OSIRIS: Optical, Spectroscopic, and Infrared Remote Imaging System.

-- Easily Confused

Rosetta, though the Mars flyby is a lot closer than I would have guessed, doesn't get all that close to Deimos, nor does the geometry look very favorable. See http://www.space.irfu.se/rosetta/sci/mars/
MEx would be able to do better on the occasion of a close flyby -- you'd think there would be some. (Edit: oops, no, the MEx orbit only goes a bit outside that of Phobos.)

Also consider what Phil said about different sun angles. Looks like the subpoint of MGS on Deimos ranges +/- 5 degrees in latitude and longitude from 0,0. Also over the ~30 hour period there's an opportunity to get just about any phase angle. Here's an animation of one 30-hour period in May:

MGS Deimos animation, May 26-27, 2006 (7.5MB MPG)

The jumps occur when MGS goes behind Mars and no view of Deimos is available.

William, of course. I don't think naming moons is more important than discovering them.

This must be a tradition with JPL - they had no formal plans with Mariner 9 to
image Phobos and Deimos until the global dust storm of 1971 essentially forced
them to show the public something other than a bland ball.



MRO took a distant image of Deimos:

http://photojournal.jpl.nasa.gov/catalog/PIA02699

Original Caption Released with Image:

This image showing the position of the Martian moon Deimos against a background of stars is part of a successful technology demonstration completed by NASA's Mars Reconnaissance Orbiter before arrival at Mars.

The spacecraft's Optical Navigation Camera was used in February and March 2006 to demonstrate the use of pictures from a small camera for calculating precise location of a Mars-bound spacecraft by comparing the observed positions of Mars' two moons to their predicted positions relative to background stars. While this technique was not necessary for the Mars Reconnaissance Orbiter's own navigation, the demonstration prepares the way for relying on it for navigating precise arrivals for future missions that land on Mars.

This example image from the Optical Navigation Camera was taken on March 6, 2006, at a distance of 1.08 million kilometers (671,000 miles) from Deimos. That moon, the smaller of Mars' two, has a diameter of 15 kilometers (9 miles), and orbits 23,459 kilometers (14,577 miles) above the planet's surface.

There are a few operational constraints; we're not allowed to point within 30 degrees of the Sun. I've been assuming that the half-phase, trailing-illuminated case is of most interest. Phil, does that sound right? I don't think I can sell a survey of phase angles, at least initially.

Thanks for the animation; very useful.

If memory serves me, the original Deep Space 1 (DS1) mission profile, which involved a Mars flyby, would have also allowed an extremely close flyby of either Phobos and/or Deimos. I remember discussing this specifically with one of the mission designers at the 1997 International Astronautical Congress in Torino, Italy. Of course, with the launch delay DS1 lost the Mars flyby opportunity.

"I've been assuming that the half-phase, trailing-illuminated case is of most interest. Phil, does that sound right?"

Yes, perfect!

Basically, as I've said, anything which adds to our coverage in this area is great. Peter Thomas will have an extra bit of input for his shape model. If in the future an additional image or two should be possible, anything which gave different phases would help too. Sub-solar longitudes on Deimos of about 225 and 315 would help reveal topography in this area.

Phil

Happy Birthday, Phil But remember what the soothsayer said to Caesar: "Beware the Ides of March." Julius Caesar (Act I, Scene II).

Well, Alex, I bewore the Ides of March as instructed... but nothing happened.

Phil

I guess you didn't get the present labeled: "To Phil from your old pals Brutus and Cassius."

Alex:

Phil, liking British comedy as he does, probably took the Kenneth Williams option:

'Infamy! Infamy! They've all got it infamy!'

Ooh, er, Matron!

Bob Shaw

Actually Frankie Howerd is the person I think of in connection with such classical goings-on. My apologies to all the non-brits out there whose upbringing didn't include frequent exposure to the cream of British culture. It is - uh - cream that floats to the top, isn't it?

Phil

"test images to be taken week of March 20"
Are they just going to snap few images of anywhere on Mars or is there some specific target for those test images...
If they asked me I would take image of Opportunity’s way to Victoria...that could help a bit in navigating through those dunes...
Does anybody knows more?

You don't just "snap anywhere" with a multi million $ camera..................

True, but the uncertainties in MOI burn performance can lead to large differences in what part of Mars will be under you during, say, 10th periapsis passage. This limits and possibly prevents any extensive planning before MOI on what targets you'll get to see.
So in a sense, they might just be "snapping anywhere", pointing nadir and catching whatever is below. It's an engineering test anyway, not scientific observation.
Once they get into their science orbit they'll have much more accurate ephemeris and be able to actually target their observations.

It's going to be March 23! Images will be taken during 2 orbits. The camera will take pictures of the middle latitudes of the southern hemisphere. (From space.com)

Does anyone know where they'll be found? I can't find any obvious links at JPL, Ames, or the Univ. of Arizona.

They'll be unveiled at HiROC in a special event if you look at the hiroc website.

Doug

I hope they'll get some shots of those canals I keep hearing everyone
talk about. Maybe even some of those ancient Martian cities along the
planet's equator made of solid crystal, or even the giant cannon they
used to launch that Earth invasion back in 1897 - and 1953 - and 1988 -
and 2005.

Interestingly enough, per the latest SPICE prediction kernel MRO won't have a periapsis passage on March 23rd UTC. There will be a periapsis around ~5:00am UTC on the 24th, which would be the 23rd Mountain Time at least.

MRO will be over the night side at periapsis so I guess the HiRISE images will be taken some time before, at higher altitudes? Here's the nadir track showing MRO as a red dot at 04:50am March 24th UTC, just going into the night side:



Altitude at that point is about 1500km. Altitude when MRO is over the Valles Marineris region is about 4000km at 04:30.

Is that the prediction based on actual orbit elements reconstructed after MOI or an a priori best-guess value?

Since it came out on March 20th I would think the former. Here's a bit of the lbl file:



Obviously most of file is based on prediction, since it covers the entire aerobraking phase out to September 14.

Yes, and that was mentioned in the original article at the beginning of this thread also, re Toma's question. Except there it was just said to be the week of March 20, but not more specific than that. Not long now...

Now, the question, as we know that the qt.exploration.edu/mars is a image repository place of MER-x images, does anyone know where will go the future MRO's images. The mro webpage (http://marsprogram.jpl.nasa.gov/mro) looks like dead, the last update was of March 10. No recent updates about the MRO's orbit status and no any new news.

The University of Arizona’s super-powerful High Resolution Imaging Experiment (HiRISE) camera is scheduled to relay first test shots of Mars on March 23 to the HiRISE Operations Center at the University of Arizona in Tucson.

Rodolfo

Sorry, don't know - but if I hear info on the location of future pics I'll post here

Unlike MER, there isn't going to be a central repository for all MRO images, because each instrument team is doing its own thing so far as I know. You'll go to the HiRISE site for their images, you'll go to the MSSS site for MARCI and CTX, etc. I still don't know the details of anyone's release policy.

For these initial test images, I'd just keep an eye on the MRO website at JPL. I don't know what the release timetable for these images is either.

Speaking to JB - he doesnt know the image release policy for CTX and MARCI yet either.

He suggested that the intention is to wait till after the test images, and then make a decision during the 6 month hiatus.

History would suggest that CTX and MARCI probably wont get the same treatment that HiRISE will, and to be fair, the baseline now is 3 or 6 month batches, 6 months after aquisition, which MER, MGS and Odyssey are doing. Wr.t. real time raw JPG's - anything in the MER or Cassini style has to be considered a major bonus ( and at no small cost w.r.t. processing and hosting ) - it's all too easy to get complacent and assume that that's the sort of thing we can come to expect - but realistically, it isnt.

Doug