MSL landing sites Options

[tuvas]

As there are some pictures being released from HiRISE of proposed MSL landing sites, I thought I'd give you what little I know about the process. As of the HiRISE team meeting a month ago or so, there were about 40 proposed sites to land MSL. These sites were prioritized, and are being photographed roughly in priority order. Each site requires a picture from each of the 3 main cameras (CTX, CRISM, and HiRISE) in their highest resolution in order to proceed. If it's determined that there can be a safe landing site, as well as interesting science targets, then they will advance to the next level, where I presume they will "wallpaper" the areas with HiRISE and CRISM (CTX, well, they get the whole landing ellipse in one shot, I think...). They likely will also photograph science areas near the proposed sites to look for interesting targets. After that, well, your guess is as good as mine. Note that none of this is official, but it's what I would expect. Also note that the landing site selection is still opened to new suggestions, the ones they have so far are not a complete list. The priority also doesn't mean anything right now other than they are the targets which will be photographed first, these priorities are still subject to change. But, well, I thought I'd send this out there for you all sink your teeth on, it really is quite interesting!

[monitorlizard]

Great to get the inside scoop on the MSL landing site process, tuvas. Do you know if all 40 sites will get high resolution stereo coverage by HiRISE, or is that being saved for the short list later?

The wonderful thing about covering so many sites at such high resolution is that many of the places not chosen for MSL will come up again as proposals for Exo-Mars, the astrobiology rover, etc. This data set will be valuable WAY into the future.

[nprev]

Tuvas, are you allowed to post the locations of any (or all! ) of the 40? Please don't do so if this would violate any of your organization's policies, but I'm sure we'd all be fascinated by this first cut...particularly since sifting through the torrent of MRO data alone is pretty much impossible unless you're rich enough to have a few score RAIDs & associated processing capability...

[mcaplinger]

Tuvas, are you allowed to post the locations of any (or all! ) of the 40?

http://themis.asu.edu/landingsites/

[Pavel]

I remember one of the requirement was that the landing site would be inhospitable to life, so that the lander doesn't introduce some microorganisms to a place where they could survive. Any astrobiological missions would probably go a place where some present microbial life is possible, e.g. next to volcanoes or to the bottom of Vallis Marineris.

[djellison]

The complete process is fully documented here
http://marsoweb.nas.nasa.gov/landingsites/...op/program.html

• Mission Overview (PDF)
• Engineering Constraints (PDF)
• Planetary Protection Constraints (PDF)

First Landing Site Workshop
May 31 through June 2, 2006, Pasadena, California

• Workshop Abstracts and Presentations
• Workshop Report (PDF)
• Workshop Summary Letter (PDF)
• Landing Site List from Workshop (PDF)
• Landing Site Voting Results (PDF)

Doug

[Phil Stooke]

33 sites were shortlisted from about 90 suggested at the first meeting. Three more were just added after being described in a poster at LPSC, and all can be seen illustrated at the THEMIS MSL landing site support page:

http://themis.asu.edu/landingsites/

Phil

[tuvas]

Great to get the inside scoop on the MSL landing site process, tuvas. Do you know if all 40 sites will get high resolution stereo coverage by HiRISE, or is that being saved for the short list later?

The wonderful thing about covering so many sites at such high resolution is that many of the places not chosen for MSL will come up again as proposals for Exo-Mars, the astrobiology rover, etc. This data set will be valuable WAY into the future.

I think HiRISE Stereo will be saved for the short list of targets. Most of the landings sites for MSL are chosen in relatively bland areas, for instance, the Marwth Vallis landing site is relatively close, but definitely not, the same as the first HiRISE transition phase image location. That area is absolutely amazing, but unfortunately not an area that one would try to land a rover... But it is a possibility to go after landing. I'm almost afraid some of the sites are going to have some bitter fights as to where to go first/next, due to the fact that MSL can actually land next to some very cool stuff, whereas the rovers had to land in relatively flat areas. MSL can actually move outside of it's projected landing ellipse, very much a plus!

[elakdawalla]

Since HiROC doesn't have a handy index to landing site imagery like ASU does for Odyssey, perhaps it'd be useful to post links here to the proposed MSL site images as they get released at HiROC.

From the 28 March release:
Proposed MSL Site in Becquerel Crater PSP_001480_2015
Proposed MSL Site in Margaritifer Basin PSP_002193_1670
Proposed MSL Site in Melas Chasma PSP_002551_1700
Proposed MSL Site in Nili Fossae Crater PSP_002743_1985
Proposed MSL Site in NE Syrtis Major PSP_002809_1965
Proposed MSL Site in Elysium/Avernus Colles PSP_002832_1770
Proposed MSL site in Xanthe/Hypanis Vallis PSP_002919_1915

From the 4 April release:
Proposed MSL Site in Southwest Arabia Terra PSP_002812_1855
Proposed MSL Site in Mawrth Vallis PSP_003063_2050
Proposed MSL Site in Nili Fossae Trough PSP_003086_2015

--Emily

[tuvas]

Since HiROC doesn't have a handy index to landing site imagery like ASU does for Odyssey

Just wait, it's coming... Sometime relatively soon, meaning the next two months, there's going to be a site redesign that'll make it easier to find images, along with reprocessing of the images to improve calibration, etc. But for now, it can be useful to have such a cheat sheet.

[lyford]

Wow - thanks Emily - this is incredibly helpful - YOU ROCK!*

Quite a bit of diversity in those pics, but I always have a soft spot for Melas Chasma. Now, whether Melas has a soft spot for MSL to land remains to be seen - Given a landing ellipse of 10km, are we confident with the skycrane steering clear to level terrain in that frame?


*Sorry, my 80's were showing.

[algorimancer]

I vote for the Hellas location. Lowest point on Mars, highest atmospheric pressure, layered deposits, channels, and generally unlike any other place visited thus far. Good stuff.

[nprev]

Me too; seems like that's where MSL might have the best chance of finding small, isolated patches of no-kidding mud at certain times of the year! Plus, I'd imagine that the denser air might reduce terminal EDL risks at least a bit.

[Greg Hullender]

Just as long as there's no actual risk of it getting stuck in the mud.

--Greg :-)

[SFJCody]

Surely one of the most important lessons from MER is that interesting chemical signatures seen from orbit (Meridiani) are more likely to result in interesting geology on the surface than interesting morphological features (Gusev). As they only have one MSL I hope they go for a phyllosilicate site.

[babakm]

Although the Meridiani sites will be a "safer" bet and would certainly help advance our knowledge of the processes that led to the hematite deposits, I can't help but think that there are a lot more new/interesting options out there. We can come back to Meridiani a few rovers from now.

[SFJCody]

Although the Meridiani sites will be a "safer" bet and would certainly help advance our knowledge of the processes that led to the hematite deposits, I can't help but think that there are a lot more new/interesting options out there. We can come back to Meridiani a few rovers from now.

Agreed, although I think that the best way of studying Meridiani as a whole would be with large static landers capable of drilling 100+m into the ground.

[centsworth_II]

...interesting chemical signatures seen from orbit (Meridiani) are more likely to result
in interesting geology on the surface than interesting morphological features (Gusev)....

It could be argued that the geology of the Columbia Hills is more interesting than
that of Meridiani.

"...composition as well as the variability along the traverse changed dramatically
once the rover reached the base of the Columbia Hills..."
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2176.pdf

In fact, it would be interesting to see, if the only choices were the Columbia Hills
or Victoria Crater, where most Mars geologists would prefer to send an MSL.

[nprev]

That's a really good argument re "follow the clays", SFJ. Targeting hematite with Oppy certainly yielded findings beyond all expectations almost from Sol 0; minerology does seem to trump morphology in all relevant particulars for a mission like MSL.

[Greg Hullender]

. . . I think that the best way of studying Meridiani as a whole would be with large static landers capable of drilling 100+m into the ground.

Strictly speaking, I think that's the best way of studying Meridianai as a hole.

--Greg :-)

[nprev]

Okay, that's the worst pun of the week...you get the virtual prize of 100 quatloos & a cookie...

[edstrick]

Considering that a mission requirement for MSL is kilometers, with ?tens? of km planned for post primary misison operations, the overriding secondary requirement for a site is accessible diversity. Yeah, that's a contradiction in terms. The overriding primary requirement is to target geology made of materials of biological and/or origins-of-life significance. There is a preliminary consensus that materials LIKE the phyllosilicate bearing terrains are top candidates.

To a certain extent, Meridiani sulfate dune deposits are "been there, done that", though we would learn much more from a revisit with new instrumentation. But there are other, vastly more complicated, exposures of Meridiani layered deposits, some in spectacular "etched" badlands in the central part and north-east parts of Meridiani Sinus (the old albedo feature.. the split in the Sinus: "Dawes Forked Bay" is actually an Earth-observable patch of high albedo badlands.

Oppy's Meridiani plains are geologically boring on the level of "if you've seen several stratigraphic sections, you've seen them all" Victoria will let us go deeper stratigraphically than Endurance, but all the evidence so far is that it's "more of the same with variations". The landing site was ideal for Opportunity, especially with it's extended treks to Endurance, the etched terrain, Erebus and Victoria, but the MSL rover would probably need to go 100 km or some large amount to get to dramatically different materials, if it was landed in Eagle crater.

Spirit was lucky. The basalt plain on the floor of Gusev was a near-disaster, though we would still have learned far more about martian surficial geology in lava plains than we learned from Vikings and Pathfinder. The pure luck in landing close enough to the uber-diverse geology of the Columbia hills made all the difference in the mission.

A "Best" landing site for MSL will be more like Gusev than Meridiani -- We will go to check out a primary mission objective set of geologic formations and materials, but we will want to have the maximum possible "go to" diversity of geologic materials of diverse geologic ages, once we've checked out and worked over the primary target. The more utterly distinct the accessible terrains, and the more different in ages the materials they can reach, the more transforming MSL will be to what we know of Mars, compared with what we will know from Viking/Pathfiner/MER/Phoenix. Spirit on Gusev lava plains, unable to reach older terrain, would have extended our knowledge. In the hills, it's transforming it.

[djellison]

MSL's a bit open ended really - some of the landing sites include a 10km 'drive to' from a safe landing site nearby.

Doug

[nprev]

Gotta love it...hopefully the 4th generation rovers will get hundreds of kms!

[elakdawalla]

An updated list of MSL sites as seen from MRO, including the May 2 releases:

From the 28 March release:
Proposed MSL Site in Becquerel Crater PSP_001480_2015
Proposed MSL Site in Margaritifer Basin PSP_002193_1670
Proposed MSL Site in Melas Chasma PSP_002551_1700
Proposed MSL Site in Nili Fossae Crater PSP_002743_1985
Proposed MSL Site in NE Syrtis Major PSP_002809_1965
Proposed MSL Site in Elysium/Avernus Colles PSP_002832_1770
Proposed MSL site in Xanthe/Hypanis Vallis PSP_002919_1915

From the 4 April release:
Proposed MSL Site in Southwest Arabia Terra PSP_002812_1855
Proposed MSL Site in Mawrth Vallis PSP_003063_2050
Proposed MSL Site in Nili Fossae Trough PSP_003086_2015

From the 2 May release:
Proposed MSL Site in Eberswalde Crater PSP_003222_1565
Proposed MSL Site in Nilo Syrtis PSP_003231_2095
Proposed MSL Site in Juventae Chasma PSP_003368_1755

--Emily

[Guest_AlexBlackwell_*]

For those playing along at home, the MSL Landing Site Selection User’s Guide to Engineering Constraints has been updated slightly (to Version 3). See http://webgis.wr.usgs.gov/msl/Engineering.htm to download.

[tuvas]

For those playing along at home, the MSL Landing Site Selection User’s Guide to Engineering Constraints has been updated slightly (to Version 3). See http://webgis.wr.usgs.gov/msl/Engineering.htm to download.

Wow, no big rocks, but not too much dust either... AFAIK, that's a pretty rare combination anywhere, I guess they want to land it in something akin to gravel... At least, that's what I'm gathering...

[elakdawalla]

I think something more like "indurated soil" would be best -- that is, something that doesn't move with the wind, but that won't be too hard to dig through.

Has anybody here thought through whether that recent Odyssey THEMIS release about ground ice being patchy has anything to do with MSL landing site selection?

--Emily

[Guest_AlexBlackwell_*]

Wow, no big rocks, but not too much dust either... AFAIK, that's a pretty rare combination anywhere...

Similar rock abundance and dustiness constraints were in place for MER. And with a much narrower latitude band, and larger landing ellipses, they still had 150+ candidate landing sites at the start of the process.

[stewjack]

The Riding with Robots Podcast has an interview with Ashwin Vasavada, Jpl's Deputy Project Scientist on MSL.

It's basically a 20 minute summary of MSL's planned capabilities. I learned a few things, but then - I haven't spent a lot of time learning about MSL.

Podcast Site
http://web.mac.com/bdunford/iWeb/Riding_wi...st/Podcast.html

Jack

[Oren Iishi]

I'm surprised that no one has talked about landing near the newly discovered Martian blackholes or possibly the guyser at the pole (although they may be too dangerous). At the very least, MSL should land somewhere that is not favorable to solar powered rovers.

[algorimancer]

Considering the moderately persuasive argument supporting the notion of a past ocean in the northern hemisphere, as reported in the current issue of Nature (http://www.nature.com.libux.utmb.edu/nature/journal/v447/n7146/full/nature05873.html - if you have access), I would be inclined to shift my preference to a landing site which would be near exposed sediments from the floor of that ocean, perhaps in delta deposits. To me, the odds are that if any macroscopic life ever evolved on Mars, it would have been in this ocean, and sedimentary deposits from the bottom of the ocean would be the best places to look for fossils, as well as a sedimentary sequence which tells an interesting story. I'm not sure whether there would be any benefit to traversing the remnant shoreline itself.

I'm having trouble matching landing site candidates with the map in the paper, but Nilo Syrtis and Marwth Vallis might be good.

[ngunn]

Agreed. In the absence of large scale drilling equipment it would be useful to visit a relatively fresh crater that has excavated through marine sediments.

[ynyralmaen]

... but Nilo Syrtis and Marwth Vallis might be good.

Mawrth, not Marwth. It's Welsh for, er, Mars.

I hope I'm not appearing to be super-pedantic here; it's just that this is a very common spelling mistake (looks like it derives from a MEX OMEGA Science paper, and some related press releases where they got it wrong.).

If you're wondering about the pronunciation, it's similar to "Martha" without the second "a"!

[algorimancer]

Mawrth, not Marwth. It's Welsh for, er, Mars.
...
If you're wondering about the pronunciation, it's similar to "Martha" without the second "a"!

Funny, I actually went to some effort to get the spelling right, and still missed it. Pronunciation sounds like "Mars" with a lisp . Perhaps all lispers are Welsh?

[ynyralmaen]

Perhaps all lispers are Welsh?

No, but having a lisp often helps!

Now that I've had longer to think about it, forget Martha... the pronunciation's exactly like "mouth", but with an "r" slipped in before the "th".

(Don't get me started on Pwyll crater on Europa!)

[Guest_AlexBlackwell_*]

Agreed. In the absence of large scale drilling equipment it would be useful to visit a relatively fresh crater that has excavated through marine sediments.

Hmm. Where have I heard that before? Someplace named Gusev or something.

[ngunn]

Aye, and the other one.

[Guest_Geographer_*]

Why does elevation matter in designing the rover? I can understand latitude mattering because of communications with an orbiter, but elevation?

[djellison]

The higher you go - the less air your parachute has to work with. 'lower' altitiudes make for an easier landing.

Doug

[Guest_AlexBlackwell_*]

You might want to take a look at the latest version of the MSL engineering constraints document, which discusses the elevation limitations.

[edstrick]

The more pounds per square foot (grams per square centimeter) of vehicle you have behind a heatshield (and a bigger vehicle is more or less inevitably deeper, front to back with more "column mass"), the less the atmosphere can slow you down before you do "ares-braking" instead of "aero-braking"...

zip..... CRUNCH!

I'm going to be off by a factor of a few times, but here's a zero'h order armwave...

Earth. 1 atmosphere surface pressure. 14 pounds (mass) of air per square inch.

Mars. 1/200'th atmosphere surface pressure. That's about 10 ounces / 30 grams per square inch. Double that (roughly) to compensate for gravity. How many ounces per square inch is the MSL in it's heat shield? There's only so many pounds of atmosphere in the way of a so many pound entry vehicle trying to slow it down.

When an entry vehicle masses more than a column of atmosphere of the same diameter between surface and space, it just can't slow down a vehicle before the vehicle hits. Would a column of atmosphere (along an entry trajectory) massing the same as an entry vehicle slow it down 50%... very very roughly, I think so (ignoring gravity).

[PDP8E]

After looking at all the MRO landing site images and counting rocks and such, it just makes sense to this complete amateur that the only place to set down MSL is on/near the famous ice packs of Elysium Planatia.

water? / ice? / extant life?

What would I add to the mission?
...bring an industrial sized RAT and BRUSH

for more info, Google: ice packs mars

[Phil Stooke]

Elysium Planitia (AKA ice pack) might look like a good landing site, but there are some problems with it. First, it might be classed as a "special region", which MSL will not be sufficiently sterilized to land in. In the event of a crash, the RTG could encounter ice and create a warm water oasis (not very big, certainly, but still viable). This is not allowed for MSL. (Phoenix should encounter ice, but it will remain very cold).

Second, MSL's instruments don't suit it. A drill might be needed to get to any ice. This could be an ideal spot for a thoroughly sterilized deep drill mission in the future.

Also, Elysium Planitia is really a one target site. Once you have looked at one location, what is there to do? It's quite uniform. MSL is designed to explore up and down a stack of sediments, or a similar multi-target site. For this reason, MSL would also be wasted on one of the 'windows' mentioned in a post above.

An ideal MSL site will have dozens of distinct targets within about 10 or 15 km of the landing site, plus a potential for a really good extended mission with many more targets over a much longer traverse.

Phil

[climber]

Elysium Planitia (AKA ice pack) might look like a good landing site, but there are some problems with it. First, it might be classed as a "special region", which MSL will not be sufficiently sterilized to land in.

Can somebody explain me why some part of Phoenix are sterilized at 300.000 spore/m² while the arm is at 1 spore/m² (source Phoenix-Launch-presskit)?
I mean, why can we sterilize MSL with the later value at least for the parts in contact with Mars ?

PS : not only there is a risk of crash for MSL RTG's but also the Crane (or whaterver you call it) will definitively crash anyway.

[James Sorenson]

Depending on what NASA's "Major" finding's that they plan to announce, and the final science results from the phoenix mission, Im wondering if Vastitas Borealis could be added to the allready 6 final landing sites for MSL?. Phoenix's landing site looks sofar VERY science rich, and worthy for exploration for another mission .

[vjkane]

Depending on what NASA's "Major" finding's that they plan to announce, and the final science results from the phoenix mission, Im wondering if Vastitas Borealis could be added to the allready 6 final landing sites for MSL?. Phoenix's landing site looks sofar VERY science rich, and worthy for exploration for another mission .

I believe that anything that far north would violate the minimum temperature limits.

[mcaplinger]

I believe that anything that far north would violate the minimum temperature limits.

True, though the limits are not entirely based on temperature. All sites must be within 45 degrees of the equator and meet other constraints. See http://webgis.wr.usgs.gov/msl/Engineering.htm

[nprev]

Mike, could you go into more detail about the lat limitations? Only thing I can think of besides temp is relay satellite availability, and that's far from guaranteed during the mission timeline; it's a somewhat puzzling constraint.

[mcaplinger]

Mike, could you go into more detail about the lat limitations?

It's mostly to do with total energy for heating of things that aren't warmed by the RTG waste heat. There are also DTE and relay geometry constraints. The site I linked to has details (in the PDF document http://webgis.wr.usgs.gov/msl/docs/MSL_Eng...uide_v4.5.1.pdf .)

[James Sorenson]

For DTE, how far above or below the horizon at the phoenix landing site would earth be?.

[djellison]

PHX doesn't do DTE But Earth on Sol 69 is moving from 4.7 degrees above the Northern horizon at 10pm local, to 47.8 degrees above the Southern Horizon at 10AM local

[James Sorenson]

I was saying DTE for MSL hypothetically if MSL were to land at the phoenix landing site .

[nprev]

It's mostly to do with total energy for heating of things that aren't warmed by the RTG waste heat...

Interesting, gotcha; thank you!

[peter59]

I wish nice reading !
Third MSL Landing Site Workshop

Cruise stage

Descent stage.


Images from Site Selection Process and Schedule by Mike Watkins

[djellison]

WOW - more funky flight hardware!!

I hope when it's all shipped to KSC, it's still in pieces. Watching that final ATLO stuff via KSC webcams was fantastic... Phoenix didn't really have much of that. Of course, what I hope more, is that it all comes together well, and on time

[ElkGroveDan]

That thing does NOT look stable.

[Guest_Bobby_*]

I found this article about The Potential MSL Site: Miyamoto Crater
It explains a lot about the geology of the site and the pluses and minuses of the site.

The article is dated September 16, 2008 and was put out by
The Martian Chronicles

http://martianchronicles.wordpress.com/200...iyamoto-crater/

[lyford]

C'mon Holden!!!!

[ustrax]

Looks like reactions weren't all the same...

"After the vote is revealed, there is some discussion of whether things were fair: (Diana Blaney: Is there a bimodal distribution related to who is in the room -- basically the 'spectroscopy' sites have sunk to the middle from comparatively favored position at early landing sites...Steve Ruff: Why did the vote go on the questions tailored in this way? A pure ranking would have been better)."

"A bunch of people are bummed out by the results (quite openly), but some are happy (less openly)."

Here.

[peter59]

Ranking

Eberswalde 44,53
Holden 43,20
Gale 41,95
Mawrth 37,92
Nili 37,08
S Meridiani 28,30
Miyamoto 23,84

Eberswalde on top ? Why not Gale or Holden?

[Tman]

They are still recommendations. But could it means the last three are droped out at least?

Go Gale! MSL will be a high mountain climber

[ustrax]

They are still recommendations. But could it means the last three are droped out at least?

Not definitely, but Miyamoto is in a really bad position...
The Nili Fossae site and South Meridiani still have a slight chance of making it since Holden and Eberswalde are locations quite close to each other, this will, probably, left one of these out of the final selection.

[djellison]

Damn you HRSC - two observations of it, and neither have colour....anyhooo

http://pds-geosciences.wustl.edu/mex/mex-m...27_0000_nd4.jpg

GO GALE. BEAT HOLDEN.

Doug

[ustrax]

Damn you HRSC - two observations of it, and neither have colour....anyhooo

Some nice anaglyphs here Doug...

[ngunn]

I've got a couple of simple (simplistic?) questions about the Gale crater central peak. Why is it so much higher than the crater rim, and why is it so neatly stratified? I've read about the supposed burial and exhumation, but if that mountain consists of sediments all the way down then surely it's not a central peak in the usual sense at all? Is it really a sort of residual mesa that is located in the middle of Gale purely by chance?

I thought central peaks in craters were normally chaotically jumbled piles of uplifted material, usually a bit lower than the crater rim. Can someone explain briefly what's hypothesised to be going on here or point me to a (not too technical) reference?

[djellison]

There's plenty of PDF's on the meeting website that talk about Gale and explain a possible history of it - most of which I don't understand ( my favoritism is purely down to aesthetics ) - but from what I do understand it's not a central peak in the way one thinks of a normal central peak ( being formed at impact ) - but has been built up since.

[climber]

MSL will be a high mountain climber

I'd love it

[peter59]

MSL landing site should be scientifically valuable, but should be spectacular also. Eberswalde is not very spectacular, Holden and Gale are spectacular. In case of similar scientific value, important PR aspect should be taken into consideration. Potential disappointment of simple US taxpayer can decrease support for next Mars missions.

[ngunn]

There's plenty of PDF's on the meeting website that talk about Gale

Thanks Doug. This 57 MB monster - http://marsoweb.nas.nasa.gov/landingsites/...Sumner_Gale.pdf
has a nice squence of diagrams. So there was no impact related central peak, the feature is all sediments, a remnant of layers that once buried Gale crater entirely. But what I still don't get is why or how a crater would empty of sediments except for one huge mound remaining right bang in the middle. Did something make the sediments there peculiarly resistant to erosion? Was there some residual volcanic or geothermal activity located near the centre of Gale that persisted for long aeons after the impact, subtly altering the sediments? My mind is wandering to the Columbia Hills . .

[djellison]

Did something make the sediments there peculiarly resistant to erosion? Was there some residual volcanic or geothermal activity located near the centre of Gale that persisted for long aeons after the impact, subtly altering the sediments?

Exactly. Let's send MSL and find out

[Tman]

MSL landing site should be scientifically valuable, but should be spectacular also. Eberswalde is not very spectacular, Holden and Gale are spectacular.

In terms of spectacular views may Eberswalde pale, but in terms of to be the most spectacular delta on Mars that probably grew in long-standing water does Eberswalde glint. To enthuse they have only to show similar delta pictures from Earth along with the explanation that large deltas are great places for life... ok probably better not, but that there is a high potential for preserved organic matter. And that crater is older than Holden.

[JRehling]

I've got a couple of simple (simplistic?) questions about the Gale crater central peak. Why is it so much higher than the crater rim

I don't know who else might believe this, but for a long time, I've thought that the story is that we have a surface that became moist (in certain seasons/epochs), leaving some salty water there for blowing dust to land on. When the water froze or evaporated, the dust grains were cemented in place. If this dynamic could be sustained, for some reason favoring this surface over other surface types, you could get runaway growth.

[monitorlizard]

I like the geology of Holden Crater and was glad to see it make the top three candidates list. However, there has been some talk in the past of the site being too cold for full operation at the time of landing. In the "Second MSL Landing Site Workshop" thread, tglotch said this in post #28:

"Holden and Terby came very close to not making the final list. They are both very interesting scientifically, but we were told by engineers that because of their high southern latitudes and cold temperatures that if MSL landed at one of those sites it would have to lie dormant for the first month or so and then operate at only a 30-50% duty cycle."

Was anything said of this at the Third Workshop? And just out of curiosity, is there some reason why RHUs (radioisotope heater units) couldn't be used instead of electrical heaters for areas not warmed by the RTG waste heat on MSL? Wouldn't that allow for less dormancy after landing?

[mcaplinger]

And just out of curiosity, is there some reason why RHUs (radioisotope heater units) couldn't be used instead of electrical heaters for areas not warmed by the RTG waste heat on MSL?

Those areas are outside the rover body and there's no obvious way that RHUs could heat them without lots of additional mass and volume for insulating enclosures of some sort.

[vjkane]

With the expectation that MSL will eventually fly, Science published an article on the down selection of MSL sites at the recent workshop. Excerpts follow:

Culture Wars Over How to Find an Ancient Niche for Life on Mars
Richard A. Kerr
In deciding how to do that [maximize science], most attendees aligned themselves with one of two parties. Spectroscopists, who find martian minerals from orbit by their distinctive spectral colors, tended to favor sites that beam strong spectral signatures of rock altered by water. Geologists, by contrast, preferred sites whose geological forms speak most eloquently of past water pooling on the surface.

Leading spectroscopists had proposed two of the seven landing sites still in the running (Science, 9 November 2007, p. 908) because the sites simply screamed "water!" to them... Bibring advocated landing on the highlands above Mawrth Vallis, a site blazing with the spectral colors of water-related minerals... For similar reasons, John Mustard of Brown University and colleagues argued for landing in Nili Fossae, a great crack in the martian crust from which MSL could drive into a side canyon where many of the half-dozen aqueous minerals of the region outcrop.

[Geologists, however, weren't convinced.] In the case of Mawrth, was the source of the clays sediment that washed into a lake? Was it volcanic ash that fell from the sky? Was it crustal rock altered by hot springs?

...many geologists favored landing in 67-kilometer-wide Eberswalde Crater. "It's the best delta on Mars," meaning a river must have flowed into a lake in Eberswalde, dropping its load of sediment on entering the still water... Other favorites of geologists were Holden Crater, another likely crater lake with layered, clay-bearing deposits but no true delta, and Gale Crater, whose 5-kilometer-high mound of layered deposits boasts a variety of water-related minerals, although the origin of the mound is uncertain.

[Del Palmer]

JPL announces final 4 candidates:

http://www.jpl.nasa.gov/news/news.cfm?release=2008-219

They are:

- Gale
- Eberswalde
- Holden
- Mawrth

[ElkGroveDan]

Is this really news? or did I miss something? I had a sense that those were the finalists anyway.

[mcaplinger]

Is this really news?

There were seven sites coming out of the third landing site workshop, and three of these were eliminated on 5 Nov, so I'd say that this counts as news.

http://marsoweb.nas.nasa.gov/landingsites/index.html

[BrianL]

JPL announces final 4 candidates:
- Gale
- Eberswalde
- Holden
- Mawrth

Apparently, final might be too strong a word. This from Ted Stryk's article in Emily's blog:

There will be a call for new sites utilizing new data; if any beat the four candidates significantly, they could be selected. Final site selection will be about six months before launch.

Boy, that would be like parachuting in a new contestant halfway through Survivor. Somebody has got to be bummed.

[Phil Stooke]

Not really! It only makes sense to take advantage of the deluge of new data, especially CRISM and HiRISE. Why stick to the old list if a really compelling new one turns up? It would have to be really good to get on the list.

Phil

[HughFromAlice]

Just a thought.....

In the light of the MSL mission statement 'Mars Science Laboratory is a rover that will assess whether Mars ever was, or is still today, an environment able to support microbial life. In other words, its mission is to determine the planet's "habitability." ' at http://mars.jpl.nasa.gov/msl/mission/overview/ and 'a growing awareness of potential, widespread mud volcanism in the lowlands of Mars' which has the potential to bring to the surface a lot of interesting chemicals - even that associated with microbial life forms if such life is/were to have existed http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1034.pdf and 'the features could be mud volcanoes but may also be sedimentary remnants from retreating glaciers. However, either way, the presence of fine grained clays in the deposits would be ideal locations to look for organic molecules, "like amonia and proteins." ' http://arizonageology.blogspot.com/2009/03...es-on-mars.html

And that a lot more could be discovered about this during the next few years before the final landing site decision will be taken...............

That a 'is still today' mud volcano type site could make an outside run in the final straight to challenge the late Amazonian phylosillicate sites. Worth watching!

[centsworth_II]

... a 'is still today' mud volcano type site could make an outside run in the final straight to challenge the late Amazonian phylosillicate sites. Worth watching!

It's a high stakes gamble: On one hand, investigating material ejected from below the surface may reveal evidence of current life. On the other hand, the amorphous dried mud ejecta may reveal no signs of current life and we would have lost the opportunity to investigate the rich history that would be revealed in layered phylosillicate sites. A history of an ancient, more Earth-like Mars.

[HughFromAlice]

It's a high stakes gamble:

You're right! It is and I respect your opinion! That's why it's an outside run and we'll need to know a lot more to tip the risk/reward balance in its favour before giving up on those millions and millions of years of layered history. But I think of the risk levels in the Apollo program - particularly Apollo 11 - and then also, what an utterly amazing prize if evidence of life were to be discovered!

If only HiRise could priority search and find a mud volcano or two near some significant phylosillicate deposits................unlikely, but...........

[Cruzeiro do Sul]

In 2000 Nasa choose to expand the envelop for MER 2003 Mission in 30% to have two roover before one previously decided.
Now the budget of MSL is over 2 Billions, so with maybe 700 millions more we could have second MSL to launch in 2013, so a back up MSL in case of failure of launch, or landing of the MSL 2011, or a second site to explore in Mars...so sad that nasa don't think about this possibility.
And now with the 2,5 billions that senate want to give to Nasa for have shuttle program continuing in 2011, we can have 3 more MSL, so the possibily to explore 4 sites with a launch in 2011, another in 2013 and two in 2016 (with planet Mars in a most favourable situation).
I know, i known... i'm dreaming .
PS: Sorry for my bad english.

[djellison]

I know, i known... i'm dreaming .

You are. There is simply not the money to do what you talk about. You also talk about the space shuttle - that is a banned subject on this forum.

[Cruzeiro do Sul]

You are. There is simply not the money to do what you talk about. You also talk about the space shuttle - that is a banned subject on this forum.

Sorry to citing the space shuttle, it was only to say how to landing in the 4 landing sites, where the money could came from.
More realisticly, i hope the other space agencies could launch their own mission to explore the other three sites that MSL will not go, begining by the Europoean Exo-Mars Mission.
One question: would it be possible for the Mid -Rover Mission, that it was one time estudied, be capable to go to theses sites?

[RonJones]

I know the sites of the potential mud volcano that were recently reported differ from the sites of the methane venting reported earlier, based on ground based observations by a team led by Michael Mumma of the Goddard Space Flight Center in Greenbelt, Maryland, and as reported in New Scientist (as quoted below):

“We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tonnes of methane,” team member Geronimo Villanueva of the Catholic University of America in Washington, DC, said in a statement.

“The plumes were emitted during the warmer seasons, spring and summer, perhaps because ice blocking cracks and fissures vaporised, allowing methane to seep into the Martian air,” he added.

One of the three regions is centred on a rift called Nili Fossae, which had until late last year been considered as a possible landing site for NASA’s one-tonne rover, the Mars Science Laboratory, which is set to launch in 2011.

The two other hotspots, each some 1000 kilometres away, have different geologies.

One centres on the southeastern region of the volcano Syrtis Major. The other is a flatter, cratered region called Terra Sabae.

However, a search for potential mud volcanos near the sites of the reported methane vents might produce interesting results and perhaps identify a potental landing site for a future mission (MSL or later).

[Nomadd22]

In 2000 Nasa choose to expand the envelop for MER 2003 Mission in 30% to have two roover before one previously decided.
Now the budget of MSL is over 2 Billions, so with maybe 700 millions more we could have second MSL to launch in 2013, so a back up MSL in case of failure of launch, or landing of the MSL 2011, or a second site to explore in Mars...so sad that nasa don't think about this possibility.
And now with the 2,5 billions that senate want to give to Nasa for have shuttle program continuing in 2011, we can have 3 more MSL, so the possibily to explore 4 sites with a launch in 2011, another in 2013 and two in 2016 (with planet Mars in a most favourable situation).
I know, i known... i'm dreaming .
PS: Sorry for my bad english.

Don't forget to budget for some really long extension cords. There's no more Plutonium 238 available for RTGs.

[gpurcell]

Don't forget to budget for some really long extension cords. There's no more Plutonium 238 available for RTGs.

They are restarting production, finally:
http://www.msnbc.msn.com/id/30621668/

[BrianL]

If MSL is now going to be partially dependent on solar power, does this not eliminate consideration of the landing sites well off the equator?

[mcaplinger]

If MSL is now going to be partially dependent on solar power, does this not eliminate consideration of the landing sites well off the equator?

The slides said only: "Rover power system design does not meet present mission requirements, requiring additional battery capacity, and possibly solar array".

I haven't heard any details about what solar options are under consideration and what constraints they might place on the mission. But it certainly hasn't been definitively decided to have solar arrays, and in my uninvolved engineering opinion, it seems pretty goofy to do so.

[nprev]

Skimmed the slides last night, and IIRC the main constraint driving the panel suggestion is the inability to operate a couple of the subsystems simultaneously? If that's correct, then an operational/procedural workaround would seem more practical (and less risky) than a major design change at this late stage.

[Phil Stooke]

Some news on the landing site front. A year ago a shortlist of four sites was chosen, but recognizing that newer data might identify better candidates the site selection team asked for new suggestions last summer. A new site would only be considered if it was at least as good as the four on the shortlist.

Seven new sites were suggested and two of them have been chosen for additional remote sensing to see how they stack up against the shortlist.

Details here:

http://marsoweb.nas.nasa.gov/landingsites/index.html

(PS look down that page - there's a section called 'from the public' hosting a few site visualizations... looks like an invitation to UMSF to add more!)

Phil

[PDP8E]

...more musings on a caffeine powered Sunday night (I should really do something about that)
I was over at the MSL Landing Site Workshop website for a few hours and ...boy.... PLEASE PICK GALE!

5km central mound that's traverse-able (that's Pikes Peak tall, 14,000 to 16,000 feet, depending where you are in the crater)
layers, sediments, most likely an ancient lake was there, and the mystery -- the mound itself. The top is higher than the crater walls. Good Luck MSL Steering Committee with your final choice next year!
Have there been any known recent active gullies spied at Gale?

[vjkane]

...more musings on a caffeine powered Sunday night (I should really do something about that)
I was over at the MSL Landing Site Workshop website for a few hours and ...boy.... PLEASE PICK GALE!

There, however, isn't a good model for how the clays and sulfides got into that peak. They could be thin layers that would be useless geologically.

Right now, the debate over the landing sites is between those where the geological story is clear and where the remote sensing says the interesting materials are.

Remember how we got skunked by Gusev Crater. Things turned out interesting, but what if the rover had landed to far away to reach those hills?

[tharrison]

...more musings on a caffeine powered Sunday night (I should really do something about that)
I was over at the MSL Landing Site Workshop website for a few hours and ...boy.... PLEASE PICK GALE!

5km central mound that's traverse-able (that's Pikes Peak tall, 14,000 to 16,000 feet, depending where you are in the crater)
layers, sediments, most likely an ancient lake was there, and the mystery -- the mound itself. The top is higher than the crater walls. Good Luck MSL Steering Committee with your final choice next year!
Have there been any known recent active gullies spied at Gale?

No, there are no active gullies in Gale—it's way outside the latitude range where gullies occur.

Any of the landing sites will tell us something interesting about Mars, but they are all very different and each have their different issues. Eberswalde is the easiest to sell to the general public because it's easy to understand—there's a delta there. Problem is the landing ellipse is very rugged, so the engineers aren't too keen on it. Mawrth has been built upon the mineralogy, but the geology of the area is incredibly complex and so it's hard to put the story together (I've been attending the MSL Landing Site Working Group telecons and Mawrth is so complex we needed more than one session to talk about it). It's the safest of the landing sites though, so it's high on the list. Holden is kind of one-note compared to the other sites, and it has some ruggedness issues like Eberswalde. Gale is definitely interesting, and even if MSL never made it to the mound, a panorama of the mound from the Mastcam would undoubtedly look amazing compared to the flat, bouldery landscapes we're used to seeing from other rover/lander missions. However, I don't think a beautiful panorama would be worth the >$2 billion price tag of MSL, so we have to take the fact that the landing ellipse is so far from the mound into account. The price tag should be (but won't, NASA HQ doesn't think like that) one of the big factors in picking a landing site—which site has enough to keep the rover occupied for 1 Mars year doing work worth the enormous price tag (which means no stopping to look at meteorites for weeks on end like Opportunity!).

[Stu]

(which means no stopping to look at meteorites for weeks on end like Opportunity!).

How VERY dare you!!!!

[Vultur]

Hoping for Holden or Eberswalde personally, for the fluvial features. But I'm sure they'd all be interesting.

[Phil Stooke]

Ok, this is off topic for MSL, though on topic for site selection... but it's not worth starting a new thread for. So I'll throw it in here.

This is a page of illustrations of potential landing sites for Mars Surveyor 2001, from the second landing site workshop just before it was cancelled. I'm posting it to celebrate (almost) finishing the first draft of my Mars atlas and my upcoming vacation.

The original plan for the mission was to carry a large rover similar to MER, and somewhere else I posted some proposed traverses for that. Then the rover was shrunk to Sojourner-class with a range of only about 1000 m, so most people didn't propose traverses. But there was one - from Nathan Bridges - which is included here. It's not a 'must-do' traverse, but a sample of what might be possible. Incidentally, trying to find that location was not simple. There are some serious flaws in the VIking image coordinates database, including its representation on the THEMIS Viking Image Map system. Sometimes the coordinates for late-mission high resolution frames are 2 or 3 degeees off.

And what about Tim Parker's 'Ibishead Peninsula'? That's no Ibis, that's a rabbit!

Phil