HiRISE and Mars Polar Lander Options

[Guest_Sunspot_*]

Looking at the images of the Spirit/Opportunity landing site, it seems many of the features such as tracks and rocket blast markings have faded considerably often to the point of being invisible in the nearly three years since landing.

This had me thinking about the MGS images taken in the hope of finding MPL. Initially it was reported that MGS had spotted the lander, one image had a white spot/streak interpreted as the parachute and a dark patch with a spot in the centre not too far off, taken to be the blast zone of the rockets with the lander in the centre.

However another image taken 5 years later seemed to discount this theory - the features had faded or changed significantly. BUT, seeing how much the rover sites have changed in an even shorter time, wouldn't the same happen to the MPL site in 5 years - perhaps to an even greater degree with the more extreme seasonal changes at that location. Also, the latest HiRISE images show just how difficult it has been to spot the landers on the surface with MGS, the Viking sites in particular.

I hope HiRISE takes another look at this spot.

Mars Polar Lander NOT Found, MSSS article:
http://www.msss.com/mars_images/moc/2005/10/17/

[Guest_Sunspot_*]

Having looked at parts of the landing site with HiRISE images, some of it looks treacherous.... I wonder, had the MPL team had images with that resolution available to them when planning the landing, would they have chosen a different area?

Also, illustrations of what MPL would look like from orbit show it with the solar arrays deployed, if it did fail during the entry phase, deployment is unlikely to have happened ? - making it even harder to see.

[ugordan]

I've now gone through all the images, all of them at half resolution except two ones (on of them being PSP_005536_1030), concentrating on rougher and brighter terrains where it would be easier to miss something. I operated under the assumption that given the jumbled look of some of the terrain with large albedo variations, my best bet would just be looking for a backshell and/or parachute. If the EDL sequnce didn't get as far as parachute deployment, finding the crash site is going to be tough to say the least. If there is a parachute and backshell somewhere, it would be readily apparent even at 50 cm/pix and this speeds up the search significantly. There was (to my eye) not a single candidate for the backshell in any of the images. Given the roughness of some of this terrain, I'd say the lander tipping over at touchdown is a pretty plausible failure scenario as well. I'm left to conclude that it either isn't located in these images (or, by some sick chance, it's in one of the data dropout gaps) or there is no backshell.

How high was MGS coverage of the landing ellipse and at what resolution? MGS later resolved the MER chutes, but that was using cPROTO.

[tim53]

How high was MGS coverage of the landing ellipse and at what resolution? MGS later resolved the MER chutes, but that was using cPROTO.

ugordon:

Indeed this is a difficult search! The MOC coverage is pretty good over the terrain where MPL was expected to have touched down if all went according to plan. I can't remember the number of images that overlapped at the "candidate object" I talk about above, but it was probably at least 2 or 3. The earliest of these was taken within 2 or 3 weeks of landing, and since it doesn't show anything unusual at that location, I have to believe that the candidate is most likely a frustratingly-lander-looking natural feature. Or (and this isn't very likely), dust accumulation was so fast as to mask the brightness of the parachute that soon after landing. And even in that overly-optimistic scenario, if the lander made it to the ground and deployed its solar panels, why didn't we hear from it? At least briefly?

The MOC coverage of the MPF landing site is particularly interesting in regards to searching for MPL, because imaging the landing site began within a year of the landing. So it's possible to look at changes in the visibility of things like the parachute over time. Because the backshell and parachute weren't visible from the ground, I didn't think the bright splotch at that location taken by MOC (http://www.msss.com/moc_gallery/ab1_m04/images/SP125603.html) was anything unusual (you can't really identify the backshell as obvious "hardware" in any of the MOC images for this reason). But since there are multiple images here, taken over many years, you can see how these objects "fade" with time.

Again, the best chance of finding MPL is if the parachute did in fact deploy, as it's potentially the most expansive piece of spacecraft hardware and ought to be verifiable in MOC images taken shortly after the landing. Since nothing unusual was identified during that search, it seem more likely that the lander crashed, or it landed outside the MOC search images - which would require it to have not landed where it was supposed to. Or the chute did deply, but may not be spread out on the surface, but clumped into a small area.

-Tim.