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Unmanned Spaceflight.com _ MSL _ MSL landing sites

Posted by: tuvas Apr 5 2007, 11:27 PM

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!

Posted by: monitorlizard Apr 6 2007, 12:33 AM

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.

Posted by: nprev Apr 6 2007, 04:02 AM

Tuvas, are you allowed to post the locations of any (or all! smile.gif ) 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...

Posted by: mcaplinger Apr 6 2007, 04:08 AM

QUOTE (nprev @ Apr 5 2007, 09:02 PM) *
Tuvas, are you allowed to post the locations of any (or all! smile.gif ) of the 40?

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

Posted by: Pavel Apr 6 2007, 04:08 AM

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.

Posted by: djellison Apr 6 2007, 08:29 AM

The complete process is fully documented here
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/1st_workshop/program.html



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

Posted by: Phil Stooke Apr 6 2007, 11:38 AM

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

Posted by: tuvas Apr 6 2007, 05:07 PM

QUOTE (monitorlizard @ Apr 5 2007, 05:33 PM) *
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!

Posted by: elakdawalla Apr 6 2007, 05:19 PM

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 http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_001480_2015
Proposed MSL Site in Margaritifer Basin http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002193_1670
Proposed MSL Site in Melas Chasma http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002551_1700
Proposed MSL Site in Nili Fossae Crater http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002743_1985
Proposed MSL Site in NE Syrtis Major http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002809_1965
Proposed MSL Site in Elysium/Avernus Colles http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002832_1770
Proposed MSL site in Xanthe/Hypanis Vallis http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002919_1915

From the 4 April release:
Proposed MSL Site in Southwest Arabia Terra http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002812_1855
Proposed MSL Site in Mawrth Vallis http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003063_2050
Proposed MSL Site in Nili Fossae Trough http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003086_2015

--Emily

Posted by: tuvas Apr 6 2007, 05:37 PM

QUOTE (elakdawalla @ Apr 6 2007, 10:19 AM) *
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.

Posted by: lyford Apr 6 2007, 05:50 PM

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 - unsure.gif 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.

Posted by: algorimancer Apr 6 2007, 06:54 PM

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.

Posted by: nprev Apr 6 2007, 10:45 PM

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.

Posted by: Greg Hullender Apr 7 2007, 03:50 AM

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

--Greg :-)

Posted by: SFJCody Apr 7 2007, 10:16 AM

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.

Posted by: babakm Apr 7 2007, 01:34 PM

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.

Posted by: SFJCody Apr 7 2007, 01:45 PM

QUOTE (babakm @ Apr 7 2007, 02:34 PM) *
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.

Posted by: centsworth_II Apr 7 2007, 03:09 PM

QUOTE (SFJCody @ Apr 7 2007, 06:16 AM) *
...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.

Posted by: nprev Apr 7 2007, 03:36 PM

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.

Posted by: Greg Hullender Apr 7 2007, 04:30 PM

QUOTE (SFJCody @ Apr 7 2007, 06:45 AM) *
. . . 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 :-)

Posted by: nprev Apr 7 2007, 08:05 PM

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

Posted by: edstrick Apr 8 2007, 07:54 AM

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.

Posted by: djellison Apr 8 2007, 08:46 AM

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

Doug

Posted by: nprev Apr 8 2007, 03:14 PM

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

Posted by: elakdawalla May 2 2007, 11:20 PM

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 http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_001480_2015
Proposed MSL Site in Margaritifer Basin http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002193_1670
Proposed MSL Site in Melas Chasma http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002551_1700
Proposed MSL Site in Nili Fossae Crater http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002743_1985
Proposed MSL Site in NE Syrtis Major http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002809_1965
Proposed MSL Site in Elysium/Avernus Colles http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002832_1770
Proposed MSL site in Xanthe/Hypanis Vallis http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002919_1915

From the 4 April release:
Proposed MSL Site in Southwest Arabia Terra http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_002812_1855
Proposed MSL Site in Mawrth Vallis http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003063_2050
Proposed MSL Site in Nili Fossae Trough http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003086_2015

From the 2 May release:
Proposed MSL Site in Eberswalde Crater http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003222_1565
Proposed MSL Site in Nilo Syrtis http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003231_2095
Proposed MSL Site in Juventae Chasma http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_003368_1755

--Emily

Posted by: AlexBlackwell May 3 2007, 10:04 PM

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.

Posted by: tuvas May 3 2007, 10:35 PM

QUOTE (AlexBlackwell @ May 3 2007, 03:04 PM) *
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...

Posted by: elakdawalla May 3 2007, 10:47 PM

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

Posted by: AlexBlackwell May 3 2007, 11:30 PM

QUOTE (tuvas @ May 3 2007, 12:35 PM) *
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.

Posted by: stewjack May 4 2007, 05:08 PM

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. wink.gif

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

Jack

Posted by: Oren Iishi Jun 12 2007, 09:43 PM

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.

Posted by: algorimancer Jun 17 2007, 03:51 PM

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.

Posted by: ngunn Jun 18 2007, 09:35 AM

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.

Posted by: ynyralmaen Jun 18 2007, 10:39 AM

QUOTE (algorimancer @ Jun 17 2007, 04:51 PM) *
... but Nilo Syrtis and Marwth Vallis might be good.


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

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.). rolleyes.gif

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

Posted by: algorimancer Jun 18 2007, 01:12 PM

QUOTE (ynyralmaen @ Jun 18 2007, 05:39 AM) *
Mawrth, not Marwth. It's Welsh for, er, Mars. mars.gif
...
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 smile.gif. Perhaps all lispers are Welsh? wink.gif

Posted by: ynyralmaen Jun 18 2007, 02:53 PM

QUOTE (algorimancer @ Jun 18 2007, 02:12 PM) *
Perhaps all lispers are Welsh? wink.gif


No, but having a lisp often helps! wink.gif

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!)

Posted by: AlexBlackwell Jun 18 2007, 06:06 PM

QUOTE (ngunn @ Jun 17 2007, 11:35 PM) *
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.

Posted by: ngunn Jun 18 2007, 07:59 PM

Aye, and the other one. wink.gif

Posted by: Geographer Jun 22 2007, 07:15 PM

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

Posted by: djellison Jun 22 2007, 07:17 PM

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

Doug

Posted by: AlexBlackwell Jun 22 2007, 07:18 PM

You might want to take a look at the latest version of the http://marsoweb.nas.nasa.gov/landingsites/msl/memoranda/MSL_Eng_User_Guide_v3.pdf, which discusses the elevation limitations.

Posted by: edstrick Jun 23 2007, 05:01 AM

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).

Posted by: PDP8E Jul 13 2007, 03:25 PM

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




Posted by: Phil Stooke Jul 13 2007, 03:53 PM

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

Posted by: climber Jul 13 2007, 04:06 PM

QUOTE (Phil Stooke @ Jul 13 2007, 05:53 PM) *
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.

Posted by: James Sorenson Aug 3 2008, 09:38 PM

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 pancam.gif wheel.gif wheel.gif wheel.gif .

Posted by: vjkane Aug 3 2008, 11:10 PM

QUOTE (James Sorenson @ Aug 3 2008, 10:38 PM) *
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 pancam.gif wheel.gif wheel.gif wheel.gif .

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

Posted by: mcaplinger Aug 3 2008, 11:30 PM

QUOTE (vjkane @ Aug 3 2008, 03:10 PM) *
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

Posted by: nprev Aug 4 2008, 12:24 AM

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.

Posted by: mcaplinger Aug 4 2008, 02:13 AM

QUOTE (nprev @ Aug 3 2008, 04:24 PM) *
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_User_Guide_v4.5.1.pdf .)

Posted by: James Sorenson Aug 4 2008, 08:49 PM

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

Posted by: djellison Aug 4 2008, 09:27 PM

PHX doesn't do DTE smile.gif 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

Posted by: James Sorenson Aug 4 2008, 09:39 PM

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

Posted by: nprev Aug 4 2008, 09:41 PM

QUOTE (mcaplinger @ Aug 3 2008, 06:13 PM) *
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! smile.gif

Posted by: peter59 Sep 17 2008, 08:30 PM

I wish nice reading !
http://marsoweb.nas.nasa.gov/landingsites/msl2009/workshops/3rd_workshop/program.html

Cruise stage


Descent stage.


Images from http://marsoweb.nas.nasa.gov/landingsites/msl2009/workshops/3rd_workshop/talks/Watkins_opt.pdf by Mike Watkins


Posted by: djellison Sep 17 2008, 09:03 PM

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 biggrin.gif

Posted by: ElkGroveDan Sep 17 2008, 09:07 PM

That thing does NOT look stable.

Posted by: Bobby Sep 18 2008, 04:56 AM

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/2008/09/16/potential-msl-site-miyamoto-crater/

Posted by: lyford Sep 18 2008, 06:43 AM

http://marsoweb.nas.nasa.gov/landingsites/msl2009/workshops/3rd_workshop/talks/Irwin_Holden_opt.pdf http://martianchronicles.wordpress.com/2008/09/17/potential-msl-site-holden-crate/!!!! biggrin.gif

Posted by: ustrax Sep 18 2008, 07:07 AM

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

"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)."

http://spaceurope.blogspot.com/2008/09/msl-3rd-landing-site-selection-meeting_3482.html.

Posted by: peter59 Sep 18 2008, 08:00 AM

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 ? mad.gif Why not Gale or Holden?

Posted by: Tman Sep 18 2008, 08:56 AM

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 smile.gif

Posted by: ustrax Sep 18 2008, 09:30 AM

QUOTE (Tman @ Sep 18 2008, 09:56 AM) *
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.

Posted by: djellison Sep 18 2008, 10:20 AM

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

http://pds-geosciences.wustl.edu/mex/mex-m-hrsc-5-refdr-dtm-v1/mexhrs_2001/browse/1927/h1927_0000_nd4.jpg

GO GALE. BEAT HOLDEN.

Doug

Posted by: ustrax Sep 18 2008, 10:41 AM

QUOTE (djellison @ Sep 18 2008, 11:20 AM) *
Damn you HRSC - two observations of it, and neither have colour....anyhooo


Some nice anaglyphs http://hirise.lpl.arizona.edu/anaglyph/msl.php Doug... smile.gif

Posted by: ngunn Sep 18 2008, 10:48 AM

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?

Posted by: djellison Sep 18 2008, 11:03 AM

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.

Posted by: climber Sep 18 2008, 11:08 AM

QUOTE (Tman @ Sep 18 2008, 10:56 AM) *
MSL will be a high mountain climber smile.gif

I'd love it smile.gif

Posted by: peter59 Sep 18 2008, 11:30 AM

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.

Posted by: ngunn Sep 18 2008, 12:04 PM

QUOTE (djellison @ Sep 18 2008, 12:03 PM) *
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/msl2009/workshops/3rd_workshop/talks/Edgett_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 . .

Posted by: djellison Sep 18 2008, 12:12 PM

QUOTE (ngunn @ Sep 18 2008, 01:04 PM) *
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 wink.gif

Posted by: Tman Sep 19 2008, 04:57 PM

QUOTE (peter59 @ Sep 18 2008, 01:30 PM) *
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.

Posted by: JRehling Sep 19 2008, 11:43 PM

QUOTE (ngunn @ Sep 18 2008, 03:48 AM) *
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.

Posted by: monitorlizard Sep 20 2008, 12:09 PM

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?

Posted by: mcaplinger Sep 20 2008, 07:33 PM

QUOTE (monitorlizard @ Sep 20 2008, 04:09 AM) *
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.

Posted by: vjkane Oct 5 2008, 12:27 AM

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.



Posted by: Del Palmer Nov 20 2008, 01:13 AM

JPL announces final 4 candidates:

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

They are:

- Gale
- Eberswalde
- Holden
- Mawrth

Posted by: ElkGroveDan Nov 20 2008, 01:24 AM

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

Posted by: mcaplinger Nov 20 2008, 01:39 AM

QUOTE (ElkGroveDan @ Nov 19 2008, 05:24 PM) *
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

Posted by: BrianL Mar 28 2009, 02:40 PM

QUOTE (Del Palmer @ Nov 19 2008, 07:13 PM) *
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. biggrin.gif

Posted by: Phil Stooke Mar 29 2009, 12:57 AM

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

Posted by: HughFromAlice Mar 29 2009, 02:06 PM

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/mud-volcanoes-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!



Posted by: centsworth_II Mar 30 2009, 07:44 AM

QUOTE (HughFromAlice @ Mar 29 2009, 09:06 AM) *
... 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.

Posted by: HughFromAlice Mar 30 2009, 11:17 AM

QUOTE (centsworth_II @ Mar 30 2009, 05:14 PM) *
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...........



Posted by: Cruzeiro do Sul Apr 2 2009, 11:08 AM

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. unsure.gif
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 rolleyes.gif .
PS: Sorry for my bad english. blink.gif

Posted by: djellison Apr 2 2009, 11:20 AM

QUOTE (Cruzeiro do Sul @ Apr 2 2009, 12:08 PM) *
I know, i known... i'm dreaming rolleyes.gif .


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.

Posted by: Cruzeiro do Sul Apr 3 2009, 02:03 PM

QUOTE (djellison @ Apr 2 2009, 11:20 AM) *
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?

Posted by: RonJones Apr 10 2009, 03:48 PM

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).

Posted by: Nomadd22 Jun 4 2009, 02:24 AM

QUOTE (Cruzeiro do Sul @ Apr 2 2009, 07:08 AM) *
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. unsure.gif
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 rolleyes.gif .
PS: Sorry for my bad english. blink.gif


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

Posted by: gpurcell Jun 4 2009, 05:19 PM

QUOTE (Nomadd22 @ Jun 3 2009, 08:24 PM) *
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/


Posted by: BrianL Jul 11 2009, 03:28 PM

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?

Posted by: mcaplinger Jul 11 2009, 04:00 PM

QUOTE (BrianL @ Jul 11 2009, 08:28 AM) *
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.

Posted by: nprev Jul 11 2009, 05:28 PM

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.

Posted by: Phil Stooke Jan 8 2010, 02:58 PM

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

Posted by: PDP8E Jul 26 2010, 01:56 AM

...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?

Posted by: vjkane Jul 26 2010, 04:15 AM

QUOTE (PDP8E @ Jul 26 2010, 01:56 AM) *
...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?

Posted by: tharrison Aug 3 2010, 12:03 AM

QUOTE (PDP8E @ Jul 25 2010, 05:56 PM) *
...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. smile.gif 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!).

Posted by: Stu Aug 3 2010, 05:25 AM

QUOTE (tharrison @ Aug 3 2010, 01:03 AM) *
(which means no stopping to look at meteorites for weeks on end like Opportunity!).


ohmy.gif

How VERY dare you!!!!

laugh.gif

Posted by: Vultur Aug 3 2010, 08:45 PM

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

Posted by: Phil Stooke Aug 11 2010, 02:52 PM

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


Posted by: PDP8E Aug 13 2010, 03:21 AM

QUOTE (tharrison @ Aug 2 2010, 08:03 PM) *
No, there are no active gullies in Gale—it's way outside the latitude range where gullies occur.
.....

Thank you Tanya for your professional perspective. It must be a excruciating decision as to where to plunk down a one-of-a-kind, $2 billion laboratory on Mars. The MSL EDL sequence is so bold, the instrument suite is fantastic, and the ground operations will test the limits of the teams. The careful deliberations of the steering committee will only increase that one small common thread with exploration, and that is serendipity ... the luck, the discovery, that seems to come out of nowhere. I wish the team all the best in deciding on a landing spot for MSL and to get those wheels down in one piece. We look forward to your insights during the whole MSL adventure.

Posted by: MahFL Aug 13 2010, 01:59 PM

The trick of course is to have the intact wheels still attatched to a 100 % functioning rover smile.gif .

Posted by: tharrison Aug 14 2010, 03:12 AM

QUOTE (PDP8E @ Aug 12 2010, 07:21 PM) *
Thank you Tanya for your professional perspective. It must be a excruciating decision as to where to plunk down a one-of-a-kind, $2 billion laboratory on Mars. The MSL EDL sequence is so bold, the instrument suite is fantastic, and the ground operations will test the limits of the teams. The careful deliberations of the steering committee will only increase that one small common thread with exploration, and that is serendipity ... the luck, the discovery, that seems to come out of nowhere. I wish the team all the best in deciding on a landing spot for MSL and to get those wheels down in one piece. We look forward to your insights during the whole MSL adventure.


The problem is that NASA does things backwards—they design a rover, put out a call for instruments, and THEN select a landing site and figure out what to do there, whereas the landing site selection should come first and then a rover should be designed to fit the goals and needs of that particular site. Gale, Holden, and Eberswalde are hugely important locations on Mars, but the MSL EDL technology is such that it is going to require a lot of luck (and again I say, not stopping to look at meteorites tongue.gif) to get to the areas of interest during the primary mission phase. Mawrth is the most likely candidate because it is not a go-to site and it's the least rugged of them all, so the engineers favor it. Even if the Landing Site Working Group were to tell NASA that a certain site was the best scientifically, HQ will still pick whatever they want. NASA doesn't always act in the best interest of science. Ultimately, Gale would be the ideal site because you've got a 5 km stack of sediments to explore, which would keep MSL busy for multiple extended missions. It would also tell us a lot about the greater history of Mars because it's only one of MANY examples of filled, buried, and partially exhumed craters on Mars (i.e. see all of Arabia Terra and northern Noachis).

Posted by: Oersted Aug 19 2010, 09:26 PM

Thx so much Tanya for joining this community: great outreach! - Those considerations of yours are VERY interesting reading.

For the moment my ambitions are to get Curiosity down safe and sound, even if it were on the most boring parking lot of Mars!

Posted by: eoincampbell Aug 31 2010, 12:12 AM

Will the landing site meeting on Sept 27-29, produce the final destination?

Posted by: djellison Aug 31 2010, 12:41 AM

No.

Posted by: nprev Aug 31 2010, 01:00 AM

Hmm. You know, final targeting doesn't really have to happen very long before launch (maybe even for a substantial period afterward?), so I don't see any urgency about selecting a site right now.

Heck, who knows; with MSL's precision landing capability, MRO might spot a really choice location that blows the others away literally any time between now & then.

Posted by: elakdawalla Aug 31 2010, 02:29 AM

Although the final choice doesn't need to be made before launch, if MER is any guide, then a latitude band will need to be chosen at launch, so a downselection will need to be made.

Anyway, the upcoming meeting is one for the Mars science community to make input. There'll be a straw poll held at the end of it I'm sure. But the final decision won't even be made by the mission. It'll be made by HQ, based on presentations on both engineering and science constraints made by the mission.

Nick, I doubt they'll be looking at any new sites. They have brought so many assets to bear on the current list of options, from HiRISE to CRISM to CTX stereo to THEMIS to god knows how many atmospheric models, that it's probably too late in the game for something new to come to the fore. Which isn't to say that there aren't any scientists who won't TRY to make a new suggestion. That'll be sort of fun to watch, but mostly just a waste of everyone's time.

I'll be going to at least some of this meeting, yay.

Posted by: nprev Aug 31 2010, 02:33 AM

Looking forward to your dispatch from the front, Emily! smile.gif I imagine that these can be quite contentious.

Posted by: brellis Aug 31 2010, 05:56 AM

Think of Emily doing a live play-by-play ustream of the event, a la http://www.youtube.com/watch?v=92vV3QGagck laugh.gif

Posted by: monty python Sep 1 2010, 06:08 AM

For some reason the Python link didn't work for me so I did a

http://www.youtube.com/results?search_query=philosophers+world+cup+monty+python=1

and chose the second option.

I hope it works or I shall taunt you a second time you son of a window dresser!


Posted by: Eluchil Sep 29 2010, 03:19 AM

The 4th MSL landing site workshop is ongoing and Emily has a thorough and insightful write-up on her blog at http://planetary.org/blog/article/00002685/

Eluchil

Posted by: tharrison Sep 29 2010, 02:11 PM

QUOTE (nprev @ Aug 30 2010, 06:00 PM) *
Hmm. You know, final targeting doesn't really have to happen very long before launch (maybe even for a substantial period afterward?), so I don't see any urgency about selecting a site right now.


Most of the urgency comes from a need to focus the efforts of the scientific community. Right now there's so much that still needs to be done pertaining to all four landing sites. If the list were shortened to two sites, it would bring more focus to those two and hopefully encourage more people to work on them and tackle the outstanding questions. For example, most of what's been done at Mawrth has focused on the mineralogy of the area, leaving the geology and geomorphology side of things a bit neglected (and it's a complicated place!).

Posted by: Gsnorgathon Sep 29 2010, 07:26 PM

And for those of us who can't get enough MSL landing site workshop news, Ryan Anderson's also blogging it at http://martianchronicles.wordpress.com.

Posted by: RonJones Jan 28 2011, 03:24 AM

Are additional MSL landing site workshops (i.e, 5th, 6th) already scheduled for 2011?

Posted by: elakdawalla Jan 28 2011, 05:40 AM

The next (and final) one is in mid-May.

Posted by: RonJones Jan 29 2011, 05:51 PM

QUOTE (elakdawalla @ Jan 28 2011, 12:40 AM) *
The next (and final) one is in mid-May.


Emily - Thanks for the update. Do you think the location of the methane "hot spots" or any other recent science findings will play a strong role in the final site selection, or will the safety of MSL be the overriding factor in picking among the remaining candidates?

By the way, why no daughter + daughter photo, or do you think the forum members would just go cross-eyed trying to view it as a stereoscopic pic?

Posted by: Phil Stooke Jan 29 2011, 10:07 PM

Methane won't figure into it. The selection is mostly based on looking at ancient clays and other water-altered or -deposited materials, plus (of course) site safety and accessibility of the outcrops. The new landing site workshop will be about identifying specific outcrops for study at each site, traverses which give access to them, and maybe potential for extended missions. Methane needs to be much better characterized by future orbiters before it can be a factor in site selection. It might just possibly affect selection for the 2018 rovers.

Phil

Posted by: tharrison Feb 3 2011, 02:42 PM

QUOTE (RonJones @ Jan 29 2011, 09:51 AM) *
Do you think the location of the methane "hot spots" or any other recent science findings will play a strong role in the final site selection, or will the safety of MSL be the overriding factor in picking among the remaining candidates?


The methane story (which may not even be real rolleyes.gif ) has nothing to do with any of the 4 candidate landing sites, and they aren't going to add any more to the list at this point.

With the extreme cost of the rover, I have a feeling that we'll end up going to a "safe" site rather than which of the 4 may be the most scientifically interesting/important site. Many folks are convinced we're going to Mawrth for this very reason (Mawrth also seems to have the most vocal advocates).

Posted by: ZLD Feb 3 2011, 02:47 PM

Just curious, which landing site do you see as the most scientificly rich?

Posted by: djellison Feb 3 2011, 03:42 PM

They're all scientifically rich, they're all safe for landing.

You should start by reading the presentations to the 4th MSL Landing Site Workshop
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/4th_workshop/program.html

Posted by: centsworth_II Feb 4 2011, 01:06 AM

But would you say they're all equally rich, all equally safe?

Posted by: djellison Feb 4 2011, 01:33 AM

Go and read the meeting presentations and find out for yourself.

All four are safe enough, that is for sure.

As for which is most scientifically interesting....ask four scientists and you'll get four totally different answers. There is no 'right' landing site.

Posted by: tharrison Feb 7 2011, 05:23 PM

QUOTE (djellison @ Feb 3 2011, 05:33 PM) *
All four are safe enough, that is for sure.


To answer centsworth_II's question though, they are not all equally safe. They have been ranked in terms of ruggedness, as well as the risk to EDL (i.e. weather conditions during the EDL timeframe). Mawrth is considered to be the "safest" site. Holden and Eberswalde are very rugged, which makes the engineers leery. Gale has some EDL concerns, plus the landing ellipse is relatively far from the mound, and so there is a concern that the rover would never make it to the mound during the primary mission (this is also a bit of a concern for Eberswalde due to the location of the landing ellipse relative to the delta).


QUOTE (djellison @ Feb 3 2011, 05:33 PM) *
As for which is most scientifically interesting....ask four scientists and you'll get four totally different answers. There is no 'right' landing site.


They may all be interesting and for different reasons, but the question is which site will you gain the most from in terms of what the rover is actually capable of doing, as well as in terms of what you will learn about the history of Mars. That's the purpose of the landing site workshops.

Posted by: elakdawalla Feb 7 2011, 05:36 PM

QUOTE (tharrison @ Feb 7 2011, 09:23 AM) *
Holden and Eberswalde are very rugged, which makes the engineers leery.

Really? That's not what they said at the most recent landing site selection meeting. From http://www.planetary.org/blog/article/00002695/:
QUOTE
We can now see just about every hazard that could possibly cause Curiosity to fail during landing using actual data, not models.

There are no hazards that we can see at any of the four landing sites that make the engineers nervous. Any one of the four sites would produce the represent the safest landing site (in terms of predicted hazards) that we have ever had on Mars.

Posted by: Julius Feb 7 2011, 06:47 PM

From what I've seen from the presentations I am inclined to favour Mawrth Vallis as my first choice for Curiosity!Eberswalde would be my second choice ..wish we had a twin rover that we could target this site as well!Mawrth being the oldest location out of the 4 landing sites makes it top choice.We should start reading a history book from the first chapter ..later chapters will make more sense if we get the the first chapter right.

Posted by: Phil Stooke Feb 7 2011, 08:01 PM

We can only go to one of the four sites... on this mission. But don't despair if your favorite site isn't picked. The other three remain as fantastic sites, extraordinarily well documented, and it's quite possible that they will be considered again in future. Just as Meridiani was the front-runner for Mars Surveyor 2001, and Gale was a MER candidate.

My preference is for... basically any site except Mawrth. Nothing wrong with Mawrth for the primary mission, but after that I'm not sure that there is an exciting extended mission. The other sites seem to offer extensive opportunities for extended traverses. But any site will be great when we're on the ground.

Phil

Posted by: djellison Feb 7 2011, 08:16 PM

QUOTE (elakdawalla @ Feb 7 2011, 09:36 AM) *
Really? That's not what they said at the most recent landing site selection meeting. From http://www.planetary.org/blog/article/00002695/:


Seconded. I saw the presentations as well and none of the sites were marked out as making the engineers 'leery' - indeed they were described as the four safest landing sites in the history of Mars exploration.

Posted by: Holder of the Two Leashes Feb 7 2011, 11:45 PM

QUOTE (Phil Stooke @ Feb 7 2011, 02:01 PM) *
We can only go to one of the four sites... on this mission.


Looking at the scientific targets for Eberswalde, you find good ones all over the landing ellipse. The biggest ones outside the landing area all seem to be to the west and south, toward the delta. So no matter where it lands, the goal will be to head this way. Ten, fifteen, twenty km or so.

Once you're at the delta, you are that much closer to Holden. About 150 to 180 km further down the road (as the proverbial crow flies).

Two for the price of one?

Posted by: brellis Feb 8 2011, 05:34 AM

After spending some great quality time rereading this thread, I have a few queries:

Do weather patterns, i.e. seasonal dust storms, play into the process for choosing a location?

Has our experience landing previous rovers improved our accuracy in predicting the degree of atmospheric drag?
(As mentioned earlier in this thread, Opportunity experienced a G-force on impact on the low end of the predicted range)

Do random gusts of wind affect the incoming G-force more than general measurements of atmospheric effects?

Elevation plays a role; does the weather change falling into a large basin?

In summary, how's the weather up there? Does it matter?

Does MSL have a dust mop??

Thanks, and this is such a wonderful site! Long live UMSF!

Posted by: centsworth_II Feb 8 2011, 06:15 AM

QUOTE (brellis @ Feb 8 2011, 12:34 AM) *
Does MSL have a dust mop??
Of course MSL does not have solar arrays to be concerned about dust buildup on. But I wonder if some other components on the deck, or the heat-radiator, might be affected by dust buildup.

Posted by: nprev Feb 8 2011, 06:48 AM

To be honest, I've had concerns in that vein regarding the steering differential lever (?) on the top deck; seems like a prime region for foreign material intrusion, and I wouldn't be too surprised if martian dust has abrasive properties.

Posted by: djellison Feb 8 2011, 06:58 AM

No more worrying than, say, the rocker bogie of MER. Passive mechanical linkages are probably not at significant risk. Motors / Flex-Cables etc...those are the troublesome parts.

Posted by: helvick Feb 8 2011, 04:08 PM

QUOTE
Do weather patterns, i.e. seasonal dust storms, play into the process for choosing a location?

Yes they do but the current sites in the selection list have been chosen, in part, because the probability of large scale storms affecting the atmospheric region important for EDL is low. If you dig into the documentation I'm sure you'll find a lot about this. Global and large scale weather is most important but some locations will have been excluded purely because the local weather has a high probability of causing unpredictable wind conditions at precisely the wrong time (just before landing).

There's a nice summary of some of the modelling work http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/4th_workshop/talks/2_Vasavada_Atmosphere.pdf.

QUOTE
Has our experience landing previous rovers improved our accuracy in predicting the degree of atmospheric drag?
(As mentioned earlier in this thread, Opportunity experienced a G-force on impact on the low end of the predicted range)

A lot of work has gone into improving the atmospheric models but most of that has come from ongoing atmospheric science activities than the relatively small sample size that has come from previous landers' EDL experiences. The important point you made there is that Opportunity was still within the predicted range at the time so it's experience can't really be used to dramatically refine those models. 7 (earth) years of coordinated atmospheric science data from the ground and the various orbiters provides a lot of really useful data for modelling. That's not to say that nothing was learned from the MER EDL data but I think it's less useful than the ongoing science.

QUOTE
Do random gusts of wind affect the incoming G-force more than general measurements of atmospheric effects?
No. The most important factor will be the broader effects that result in the raising (or lowering) of the atmosphere, changing the density profile and high altitude winds (in the 30km to 2km altitude range) during the descent. A bad atmospheric model would have the descent stage hitting critical points at velocities that were a couple of orders of magnitude out of line with reality or many km's off track, a bad wind gust\downdraft at lower altitudes would have effects that are serious but a lot less dramatic. That still has to be considered and dealt with but it's not the same magnitude of problem.
Edited to add some facts to my speculation smile.gif
Apparently the EDL data from the six successful landers is critical because it provides higher resolution data than any other mechanisms for critical parts of the modelling problem so I'm wrong there - http://www.lpi.usra.edu/meetings/modeling2008/pdf/9025.pdf.
End Edit.

QUOTE
Elevation plays a role; does the weather change falling into a large basin?

Yes it does, just as it does here on earth but again it's the broad characteristics (bulk density\temperature) rather than small scale effects like wind gusts and direction that are most important. It's a lot easier to land at very low elevations because there is a lot more atmosphere to make use of on the way down both in terms of simple distance and atmospheric mass that can be used for braking.

QUOTE
Does MSL have a dust mop??

I'm not even going to go there, we've thrashed that to death far to often in the past.

Posted by: tharrison Feb 8 2011, 08:35 PM

QUOTE (djellison @ Feb 7 2011, 12:16 PM) *
Seconded. I saw the presentations as well and none of the sites were marked out as making the engineers 'leery' - indeed they were described as the four safest landing sites in the history of Mars exploration.


I was at the landing site workshop as well, but that statement doesn't match what I'm hearing behind the scenes as a member of the operations team. Yes, they have all been dubbed as "safe" for landing, but they've still been ranked in terms of relative safeness. Eberswalde was very near the cutoff for being dubbed "safe" (there is basically a percentage of risk assigned to any landing site and to make the cut the risk has to be below a certain percentage), and Mawrth is considered to be the safest. The rover *should* be fine at any of the four sites, but with the cost being as high as it is, I can see them wanting to take as few risks as possible to make sure the mission lands successfully. Again, it's all relative.

QUOTE (helvick @ Feb 8 2011, 08:08 AM) *
7 (earth) years of coordinated atmospheric science data from the ground and the various orbiters provides a lot of really useful data for modelling.


We actually have nearly 12 Earth years of continuous weather data from Mars between the MGS MOC (wide angle) and the MRO MARCI. Daily color global mosaics of the entire planet were started in mid-March of 1999 by the MGS MOC. Pretty darn cool. smile.gif

Posted by: Drkskywxlt Feb 9 2011, 12:52 AM

QUOTE (nprev @ Feb 8 2011, 01:48 AM) *
I wouldn't be too surprised if martian dust has abrasive properties.


So much of the pitting we see on rocks lying on the surface are inferred to be due to abrasion by airborne dust over long periods of time, no? So it surely is abrasive. I wouldn't think it would be quite as abrasive as lunar dust (with the very high surface area to mass ratio) given that martian dust gets lifted into the air and knocked around quite a bit more than lunar dust, which should smooth it down somewhat.

Posted by: Oersted Feb 10 2011, 12:04 AM

QUOTE (helvick @ Feb 8 2011, 05:08 PM) *
Edited to add some facts to my speculation smile.gif
Apparently the EDL data from the six successful landers is critical because it provides higher resolution data than any other mechanisms for critical parts of the modelling problem so I'm wrong there - http://www.lpi.usra.edu/meetings/modeling2008/pdf/9025.pdf.
End Edit.


Big credit to you for this display of a self-effacing, scientific attitude. Data rocks and so do you! smile.gif

Posted by: Oersted Feb 10 2011, 12:07 AM

I much prefer Eberswalde, just avoid the built-up area:

http://www.google.be/maps?ll=52.833106,13.819599&spn=0.023179,0.066047&t=h&z=15&iwloc=lyrftr:com.panoramio.all,pp:13104377,52.833119,13.81961&lci=com.panoramio.all

laugh.gif

Jokes aside: a river delta fed by MEANDERING rivers! - What is there not to like?

http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/4th_workshop/talks/6_Dietrich_Eberswalde_opt.pdf

- Great read.

Posted by: KrisK May 16 2011, 10:05 PM

So we've got the Fifth MSL Landing Site Workshop (May 16 - May 18, 2011) smile.gif
http://marsoweb.nas.nasa.gov/landingsites/index.html

Here is a nice quick characteristics of the landing sites (pros, cons, unknowns)
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/5th_workshop/First_Draft_Quad_Charts_for_5th_Workshop.ppt

Posted by: KrisK May 18 2011, 10:10 PM

Fifth MSL Landing Site Workshop presentations smile.gif
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/5th_workshop/program.html

Can't wait to see MSL wheel.gif wheel.gif wheel.gif on Mars...

Posted by: sgendreau May 18 2011, 10:36 PM

QUOTE (KrisK @ May 18 2011, 03:10 PM) *
Fifth MSL Landing Site Workshop presentations smile.gif


I'm sitting in the audience at the workshop, watching the final discussion on site pros and cons. Very smart people in ferocious debate. Most of the audience is fiercely in one of the four camps. Matt Golombek and John Grant are trying (some but limited success) to extract consensus on each site's points. Since I have no horse in the race, watching the race is fascinating.

EDL is very very sure of themselves at all four sites. Science-wise, no site seems to have an edge. Anyone have a specific interest or question? No promises but I'll try.

Posted by: dmg May 18 2011, 10:51 PM

The workshop is available for viewing/listening via a Webex feed (https://jpl.webex.com) and anyone can sign up to see/hear. I've been listening and watching out of the corner of my ears/eyes for the last couple of days and it is fascinating to watch the process take place. For each site they are fighting over a "quad chart" that delineates the Overarching Hypothesis; the Possible Pros; Possible Cons; and Remaining Uncertainties. These have been developed over the prior MSL Landing Site Workshops and are being modified as they speak. There were a couple of days of presentations and now an open discussion, site by site, of the Pros, Cons, and Uncertainties. Very interesting (even though most of it is a bit above my head -- I get the gist of the discussion).

Posted by: centsworth_II May 18 2011, 11:42 PM

QUOTE (sgendreau @ May 18 2011, 06:36 PM) *
...Science-wise, no site seems to have an edge....
What stirs my imagination is this from the Mawrth Vallis quad chart: "Exposes the oldest preserved layered stratigraphic section of the four candidate sites... may be among the oldest preserved on Mars and may be from a period not recorded in the rock record on Earth." Just as Studying Titan may give insight to early Earth atmosphere, studying Mawrth may give the best insight to early Earth geology -- and definitely give the best insight to early Mars geology. I like the idea of studying layers formed at the time when early life may have been getting its start on Mars. We don't have this opportunity on Earth.

I also agree with this: "Steve Ruff making a forceful point if all 4 sites OK, why pick 1 of 3 Go-To sites rather than Mawrth where landing site has science?" And don't agree with Jim Bell Response as reported on Twitter (below). The keys are not being thrown away. They are being used to go yet further after landing site science is done. To me, if the quality at all four sites is equal, then the site where substantial science can be started sooner has the advantage of quantity in addition to quality.

Posted by: elakdawalla May 19 2011, 01:12 AM

It's not that simple, though. Paolo showed a chart today that made it clear that of the four sites, Mawrth makes for the slowest and most challenging driving. (Eberswalde is also on the difficult side, compared to Gale and Holden.) Why would we go to a place where we had to fight our way across ripples and around undriveable slopes if we could go to a place with clear driving between science sites, where blind driving plus autonav can take us far, far away from our landing site into a new geologic context? Field geology is all about traverses -- going as far as you can, sampling along the way, to see how things change, look for geologic contacts, and always keep moving.

I'm not actually saying I prefer other sites over Mawrth. People keep asking me which one I prefer, and I just don't have a favorite, because to have a favorite I would need to understand all the arguments better, and I just haven't been paying good enough attention. The one I am most concerned about is Eberswalde, because there is a distinct possibility that that incredible delta system all formed in a very short period of time, so I think it would be less valuable than the longer geologic histories represented at the other sites.

Posted by: nprev May 19 2011, 02:59 AM

I think Emily has an excellent point. One thing to remember is that MSL is likely to be quite long-lived, even by MER standards (yeah, that was a shout-out! wink.gif ) Inherently sudden/catastrophic events are interesting in their own right, but they have more of a gee-whiz factor than a root science potential.

Maybe the debate should refocus on the science objectives in this context. My understanding, though it might be wrong, is that one of MSL's core goals is to ascertain not only whether Mars once possessed a habitable environment but also (crucial point) how long it may have persisted. Eberswalde does not seem to offer as much potential to address that question as some of the others.

Posted by: elakdawalla May 19 2011, 03:44 AM

John Grant and Matt Golombek kept coming back to the tired metaphor of apples and oranges. Mawrth is apples; the other three are oranges. In the room there are people who prefer one or the other, have spent their careers studying one or the other, and really, no amount of argument is going to change their minds. Changing their minds wasn't really the point, which is why no vote was taken. The minds that matter are the ones who were sitting in the front row -- John and Matt, John Grotzinger, the engineers, the HQ folks. They will make the decision between apples and oranges.

Posted by: PDP8E May 19 2011, 05:02 AM

MSL Landing Site team:

Holden seems like Gusev... to this armchair martian explorer, do we really want to look at another volcanic littered and billion year wind-swept and dust covered crater? Is there a Home Plate fumarole there to study... or mud volcanoes?

The delta of Eberswalde may not be easy to maneuver around; and its a negative delta, the braids, are now raised very high.

Mawrth... what a place. An extensive valley with everything at your landing spot.

And then the 150 mile Gale Crater. It has a Pike's Peak sized mountain in the middle. The experts don't know what it is or how it got there. Within the crater is a crazy deep and layered valley that we can cozy up to and study (albeit, from afar). The traverse up Pike should reveal many surprises.

What is the purpose of MSL? looking for water? looking for geographic layers? looking for life? or just maybe exploring the unknown and unknowable? If we lived on Mars and tried to pick a landing spot on Earth a half a million years ago, would we choose the Sahara or the Grand Canyon?

Pick one.

Explore, seek, and learn. The landing attempt via the sky crane is very bold engineering. Landing Site Pickers: be bold.

Pick one.

With the history of exploration as our guide, this is a just the beginning of exploration. You really can't pick wrong.

Pick one.

< i now step off my soapbox ... thank you >

Posted by: jasedm May 19 2011, 05:21 AM

QUOTE (PDP8E @ May 19 2011, 06:02 AM) *
If we lived on Mars and tried to pick a landing spot on Earth a half a million years ago, would we choose the Sahara or the Grand Canyon?


Neat analogy.

If that were the case though, we'd probably be designing a craft along the lines of WISE, and be aiming to drop it into the Pacific....

Posted by: Eluchil May 19 2011, 05:30 AM

They are all excellent sites. I must say, though, that unlike MER where I become a convert to Gusev after reading a presentation about how the Athena science payload could be used to directly test hypotheses there, I already had my mind basically made up. When I first saw the meanders of Eberswalde (back when it had no name and was called Holden NE for reference) I knew that was where I wanted a lander to go.

In reality, there are real concerns about the site and one of the others may be just as good or better, but emotionally it would be a literal dream come true to have a lander at Eberswalde.

More generally, I think that morphology provides more concrete hypotheses to test than mineralogy does. And a clear result, even a negative result like that ultimately derived at Gusev, is very valuable.

Posted by: elakdawalla May 19 2011, 05:51 AM

This decision is the battle of mineralogists vs. geomorphologists all over again, and we know who "won" the fight, at least initially, on MER: Meridiani (the mineralogists' choice) provided almost instantly the results that the mission was searching for, while Spirit wound up in the infamous "basalt prison," not finding evidence for past water until Pot o'gold. So it would seem obvious to pick Mawrth. But there is a HUUUUGE difference this time around: MRO. Between HiRISE and CRISM the amount we know about what's there to see at outcrop scale has increased by orders of magnitude. Remember it's CRISM data that's drawing Opportunity all the way to Endeavour. CRISM certainly points to Mawrth as a very interesting spot. But HiRISE has equivocal stuff to say about Mawrth. And if you can't understand the local geologic context, no matter what you learn at the landing site you won't be able to understand its implications for other places on Mars, which would represent a failure of at least one mission goal (though if Curiosity sees dinosaur bones at Mawrth, no one will care about that particular failure).

Another point is that the mission people, Grotzinger especially, keeps hammering on, is this preservation issue. We'd like to know if there were organics present at a time where there was water and energy, because these are the ingredients for life (we think). But organics get destroyed so easily by water. Mawrth is so ancient, and appears to have had so much water (relative to other places) that you have to question whether any organics that may have been present would have been preserved. I wasn't there, but I suspect that it was concerns like this that led Bibring to comment "I am amazed that now we are saying there's too much water on Mars!" (a quote reported via Twitter). I was talking with Jeff Kargel afterward and he said that his impression was that the best hope for preservation would be in stacks of rocks that contained both phyllosilicates and evaporitic stuff, implying occasional total drying out of the landscape. Mawrth does have the evaporitic stuff in the form of sulfates. So does Gale. Mawrth has higher abundance of these interesting minerals (though it's really incredibly difficult to get abundances out of spectra, so that statement could be false). Gale has a thicker section.

Back and forth. If forced to bet, I'd hedge by laying money on both Mawrth and Gale. I'm told it's entirely possible that the mission will narrow the choices down to two and punt to HQ for the final decision. But I hope they don't -- that seems like a kind of cowardly way out.

Posted by: SFJCody May 19 2011, 08:08 AM

QUOTE (KrisK @ May 19 2011, 08:10 AM) *
Fifth MSL Landing Site Workshop presentations smile.gif
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/5th_workshop/program.html



Found UMSFer Edwin Kite's presentation to be very interesting. He's performing a valuable service- forcing people to question romantic assumptions about Martian sedimentary rocks. Is he the new Nick Hoffman?

Posted by: Deimos May 20 2011, 03:16 PM

QUOTE (PDP8E @ May 19 2011, 06:02 AM) *
Holden seems like Gusev... to this armchair martian explorer, do we really want to look at another volcanic littered and billion year wind-swept and dust covered crater? Is there a Home Plate fumarole there to study... or mud volcanoes?


I truly do not see where this comes from. Light-toned layered deposits. Phyllosilicates. Fluvial channels within the driving range. And the complicating factor in the ellipse is alluvium (with ripples), not basalt. This is not one of my favorite sites .. but "like Gusev" misses the mark.

QUOTE (PDP8E @ May 19 2011, 06:02 AM) *
The delta of Eberswalde may not be easy to maneuver around; and its a negative delta, the braids, are now raised very high.

It would be great to get to the top. But you're right, MSL likely won't. But the science targets are reachable, and the driving to get there is easier than at Mawrth.

QUOTE (PDP8E @ May 19 2011, 06:02 AM) *
Mawrth... what a place. An extensive valley with everything at your landing spot.


Hmm. Everything in the ellipse. Well, mostly--the sulfates are outside the ellipse. But that's very different from everything at your landing spot. Especially with slow traverses. If Go-to capability is somehow limited, it hurts a Mawrth investigation less then the other sites--it does not let Mawrth off the hook.

QUOTE (PDP8E @ May 19 2011, 06:02 AM) *
And then the 150 mile Gale Crater. It has a Pike's Peak sized mountain in the middle. The experts don't know what it is or how it got there. Within the crater is a crazy deep and layered valley that we can cozy up to and study (albeit, from afar). The traverse up Pike should reveal many surprises.


Don't sell the mound short. It looks down on Pike's Peak. By a factor of 3. Peak altitude with respect to the mean datum is irrelevant--by that standard, Gale's mound is a bump; PP much taller. Stand at the base and look up. The mound is Mt. Logan; or Mt. Rainier on steroids (in size, and a little bit in shape--of course it is layered sediments). From the base, it is 5 km of exposed sediments, not a paltry 1.6 km ;^) . That said, of course MSL's investigation will be vastly less than 5 km; but there would be some pretty pictures.

Separately, I agree with Jim Bell. We have the capability to drive, to "go to" a site out of the ellipse. We should use it IF it gets us what we want, and that should be decided on the merits. The rallying cry should not become, "Why settle for the best when you can hold out for good enough." Many think Mawrth is best, and they certainly don't want to settle. But the Ruff-ian argument that those who favor other sites should forsake go-to as soon as Mawrth gets over some "good enough" bar -- well, that should waste the patience of explorers.

Posted by: Julius May 20 2011, 03:30 PM

I'm still GO for Mawrth!! Lets get down to business straight away and not waste time driving .....we'll have time to study ancient martian history which we havent done yet from the ground..done with that, we can then drive to other sites provided the goals are met early in the mission.. all extra will be bonus!! Besides we dont have any guarantees the mission will last as long as MERs

Posted by: djellison May 21 2011, 05:05 AM

QUOTE (Julius @ May 20 2011, 08:30 AM) *
Lets get down to business straight away and not waste time driving


If that were the case, we would be sending a lander. Mawrth, as with all the others, has specific targets that require driving. Moreover, all the sites have good science within their landing ellipses. Mawrth is not special in this regard.

QUOTE
Besides we dont have any guarantees the mission will last as long as MERs


We DO have a requirement for 2 years on the ground. All of the sites driving requirements and science requirements can fit within that time span.

They are essentially indistinguishable in terms of scientific merit and EDL safety.



Posted by: nprev May 21 2011, 06:42 AM

Well said, Doug.

To me, it all comes back to a careful read of the stated science goals. Somewhat unfortunately, this isn't much of a discriminator; Mars has a very rich history as is increasingly revealed by MRO & other orbiters, reinforced by the ground truth of the MERs. On top of it all, the EDL system is purportedly robust enough to handle any of the four finalists

I can well understand the indecision. If we were to land on Earth, where would we go to achieve maximum science return? I don't even have a clue. Mars is not as environmentally diverse as Earth, but it's a hell of a lot more diverse than we originally thought not too long ago.

There's probably not a right answer. All remaining candidate sites have something to offer. Therefore, to be utterly pragmatic & honest, it's time to ask the engineers. They apparently are saying that they can set MSL down anywhere the scientists want it to be, but surely one of these sites is easier than the other three iin some respect. I suggest that they should be consulted for a high-res look at exactly which site offers the least landing risk if there are no other compelling discriminatory factors.

Bottom line is that there's gotta be a choice made soon. MSL has the potential to conduct a regional survey of its landing site. Which area would provide the maximum information with respect to the major questions about Mars and its history given that capability?


Posted by: Julius May 21 2011, 01:14 PM

Of course I expect some driving to get to targeted sites but driving 1 km to get science is certainly preferable than having to drive 30km!! Requirement for mission success is 2 years for MSL which is more robust than MER... yes I see your point Doug but it doesnt mean that it will last that long.....dont get me wrong, I wish MSL all the success and better science returns than MER but you never know what MARS may hold for MSL!!??

Posted by: djellison May 21 2011, 01:58 PM

QUOTE (Julius @ May 21 2011, 05:14 AM) *
but driving 1 km to get science is certainly preferable than having to drive 30km!!


I'll repeat myself : The sites all have interesting science within their ellipse, and, repeating myself again, Mawrth involves driving to science targets as well. Your entire premise is flawed. You clearly have not read the presentations that the landing site meeting put online.

QUOTE
t it doesnt mean that it will last that long


So how long do YOU think it will last. What assumption are you going to make about its lifespan that drives your preference to Mawrth. What drives your decision to think you know how long the vehicle will last better than the engineers responsible for designing, building, testing...and driving...the vehicle? The level 1 requirement is 2 years. To make ANY assumption regarding longevity other than that is folly.

QUOTE
but you never know what MARS may hold for MSL!!??


Yet you're making assumptions about Mawrth, and indeed the other sites, that the data simple doesn't support. If you wish to make a case for Mawrth, then you need to demonstrate that it is scientifically more attractive or safer to land on or drive around.

The project scientists and engineers were basically unable to do that.

Posted by: ngunn May 21 2011, 03:44 PM

This is a beginner's question, quite possibly asked and answered before. Suppose Curiosity were heading with few distractions toward a distant target much as Opportunity is now, what distance is it expected to cover in one good day?

Posted by: Julius May 21 2011, 04:45 PM

I'm hoping MSL will last a lifetime! I'm not in a postion to judge on the eventual site selected and I trust that the engineers and scientists will make the best choice at the end. All I am saying is that I prefer Mawrth for the simple reason that it represents the earliest Martian history compared to the other sites. Its like reading a book..u want to read from the start rather than start from the middle section for it to make more sense. This is my judgement. Whether I am right or wrong I'll leave it to the people directly involved in this decision.I'll be happy with whatever they decide. At the end of the day what counts is that we'll have another Mars mission to follow for years to come and that makes me excited wherever it happens on Mars!

Posted by: charborob May 21 2011, 05:11 PM

QUOTE (djellison @ May 21 2011, 01:05 AM) *
They are essentially indistinguishable in terms of scientific merit and EDL safety.

I've been loosely following this discussion and the debate around the choice of the MSL landing site, so maybe my comment is ridiculous, but anyway...
If all the sites are equally rich scientifically, I suppose that means the interesting stuff at each site is accessible within the 2-year mission requirement. Of course, we don't know in advance if there will be any mission extensions. We can only hope. Or if MSL will die before 2 years on Mars (heaven forbid!). In any case, would it not be a good idea to plan a little bit in advance? We could take as a hypothesis that MSL will last longer than 2 years and ask ourselves: once we have studied the landing zone thoroughly, where do we send the rover? Suppose at one site the next interesting geology is (say) 50 km away, and at another site 20 km away (just throwing numbers around), then if all 4 sites have equal scientific merit, why not send MSL to a site having a higher "concentration" of various interesting geologic features?

Posted by: ilbasso May 21 2011, 09:18 PM

To say that "To make any assumption other than [the design requirements] is folly" is not entirely accurate. If I may reference a manned program, remember that the first task that Neil Armstrong had upon getting onto the Moon's surface was to scoop up a contingency sample in case something unforeseen went wrong and he had to get out of there quickly. The design requirement for the LM was to stay on the Moon for 24 hours, but prudence dictated preparing for the unexpected.

Given the investment in the MSL platform and that there's just one shot at getting the science from her, prudence would seem to dictate putting her as close as possible to the priority targets of interest within the constraints of EDL etc. and not assuming that just because she's designed to last 2 years, she will necessarily have that long.

Posted by: ngunn May 21 2011, 09:51 PM

Just one person's view, but I think it would be be good to lay off the landing site discussion. I live in Wales, FWIW.

Posted by: centsworth_II May 21 2011, 09:53 PM

QUOTE (ngunn @ May 21 2011, 11:44 AM) *
...what distance is it expected to cover in one good day?

A quote from The http://www.planetary.org/blog/article/00002675/ (and a comment to that blog):

"Sean Haggart, the mobility engineer doing the narration, mentioned in the video that Curiosity's top speed is 4 centimeters per second, which is actually slower than what I've heard quoted for Spirit and Opportunity's top speed (5 cm/sec)."

"I remember a JPL lecture in which it was stated that the maximum blind-drive distance per hour for MSL is 210-m, versus 180-m for MER.
#3 - Bob Ames - 09/21/2010 - 04:55"


So Curiosity really doesn't travel any faster than Opportunity.

The remaining factor is how long Curiosity can drive. She has more power than Opportunity, but it takes more power just to move that hulk. It may end up being a wash, with Curiosity not consistently outdoing Opportunity's best pace. It will be interesting to see how long Opportunity holds on to her Mars distance record.

Posted by: Explorer1 May 21 2011, 10:42 PM

How long do they have to decide on the final site? Could it even be left for after launch, or do course corrections and such have to be planned out way ahead?

Posted by: nprev May 21 2011, 10:55 PM

I believe that it does have to be decided before launch, since MSL will be on a direct trajectory to Mars just like the MERs, Phoenix, and Pathfinder. (The Vikings were in Mars orbit first, so they at least could select from sites achievable from their orbital planes.) Don't think that the cruise stage will be capable of doing anything but minor course corrections & attitude adjustments.

Posted by: ElkGroveDan May 22 2011, 12:09 AM

QUOTE (nprev @ May 21 2011, 02:55 PM) *
I believe that it does have to be decided before launch, since MSL will be on a direct trajectory to Mars just like the MERs, Phoenix, and Pathfinder.

My understanding is that it WILL be decided before launch but that there is also an ability to re-target the landing site in-flight, though it does start to affect the size and shape of the ellipse as time goes by.

Posted by: nprev May 22 2011, 12:55 AM

Dig it. I suspect that retargeting is far from the most desired course of action, though; not only would it cost considerable enroute consumables, it would also decrease landing precision as you described, Dan.

Posted by: Greg Hullender May 22 2011, 01:31 AM

QUOTE (centsworth_II @ May 21 2011, 01:53 PM) *
The remaining factor is how long Curiosity can drive. She has more power than Opportunity, but it takes more power just to move that hulk. It may end up being a wash, with Curiosity not consistently outdoing Opportunity's best pace. It will be interesting to see how long Opportunity holds on to her Mars distance record.

Curiosity will be active at night (and in the shade too). Of course they might not want to drive at night :-) but does Opportunity really manage to drive from dawn to dusk or is it only some fraction of daylight? Also, I'd expect Curiosity can do at least some science at night that Opportunity is forced to stop for during daylight hours.

Add all these factors together, and I expect either a) Curiosity manages maybe 2x the speed of Opportunity or cool.gif Curiosity goes places Opportunity couldn't attempt.

Posted by: infocat13 May 22 2011, 01:34 AM

one of the presenters with, I believe a Gale crater paper,presented a proposed route along with the geology to be found at each elevation.
http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/5th_workshop/talks/Tuesday_AM/Anderson_Gale_Traverse_compressed_final_opt.pdf
if indeed all of these sites have compelling scientific merit, then there is one more factor to be considered,
The impact of images returned to the public imagination!
I remember watching on TV the Apollo 8 mission, and the earth rise photographs.The Gale creator presenter promised a compelling scenery, perhaps it is this consideration that should be added to the final decision.
the public so engaged might very well influence future decisions on planetary exploration.if all 4 candidates are scientificly compelling and are equaly safe for landing, http://marsoweb.nas.nasa.gov/landingsites/msl/workshops/5th_workshop/talks/Wednesday_AM/Golombek_5th_Work_Char_v2.pdf then pick one that holds promise to excite the public imagination to ask for more funding smile.gifsmile.gif for future exploration.
Hubble is an example of such a machine that excites the public imagination.

Posted by: djellison May 22 2011, 03:51 AM

QUOTE (Greg Hullender @ May 21 2011, 05:31 PM) *
Curiosity will be active at night (and in the shade too).


Oh, the oft repeated and oft corrected myth. Curiosity will have a power budget just like MER. Just because it's got an RTG doesn't mean it's awake 24/7. It'll be asleep at night, just like MER. What MSL will be doing at night is recharging its batteries. Moreover, in shade - it'll be colder than average and thus require even more actuator heating (already a significant power budget burden)

The RTG renders the power supply more reliable. It doesn't render it infinite.

Posted by: djellison May 22 2011, 04:02 AM

QUOTE (ilbasso @ May 21 2011, 02:18 PM) *
Given the investment in the MSL platform and that there's just one shot at getting the science from her, prudence would seem to dictate putting her as close as possible to the priority targets of interest within the constraints of EDL etc. and not assuming that just because she's designed to last 2 years, she will necessarily have that long.


Again - if that's the case, send a lander. We've spent a fortune making a mobile vehicle...yet you're advocating not using it. It's like dangling keys infront of the science team, but not letting them use them. Moreover, again, all the landing sites have good stuff within their ellipses, and Mawrth would require driving just like the wrongly titled 'go to' landing sites.

Posted by: Greg Hullender May 23 2011, 01:27 AM

QUOTE (djellison @ May 21 2011, 08:51 PM) *
Moreover, in shade - it'll be colder than average and thus require even more actuator heating (already a significant power budget burden)

Except that the RTG is generating much more heat than power. Even if it's charging its batteries, it ought to have a lot more heat available than the other rovers ever did. I'd expect getting rid of that heat would be a big problem. I'm surprised if it'd need to actually use electric power to heat anything.

Of course, I've been surprised before . . .


--Greg

Posted by: djellison May 23 2011, 01:42 AM

QUOTE (Greg Hullender @ May 22 2011, 06:27 PM) *
I'm surprised if it'd need to actually use electric power to heat anything.


Then be surprised. Mobility heating represents a significant portion of the daily power budget. Indeed some previously considered landing sites were expected to be so cold that there would be significant no-drive periods as the mobility heating requirements would be so bad, they were unsustainable. This is covered in earlier landing site selection meeting documentation.

Posted by: djellison May 23 2011, 02:08 AM

QUOTE (ElkGroveDan @ May 21 2011, 05:09 PM) *
My understanding is that it WILL be decided before launch but that there is also an ability to re-target the landing site in-flight


Yup - by the 3rd landing site meeting, they had established that they could target any site between 30N and 30S by targeting at TCM1.

Posted by: Eluchil May 23 2011, 04:31 AM

Come to think of it it really is TCM1 not launch that is the drop dead date. Though the decision will be made and announced before then I am sure. At launch the space-craft is targeted slightly away from Mars so that the third stage of the rocket doesn't hit the planet. It's too big to sterilize and everything that hits Mars has to be relatively clean of bacteria according to the http://planetaryprotection.nasa.gov/. Thus it's only with TCM1 that the spacecraft is aimed directly at Mars at all giving a fairly wide choice of landing sites from any single launch profile.

Posted by: centsworth_II May 23 2011, 04:48 AM

"http://www1.nasa.gov/mission_pages/mars/images/20081209_msl.htmlThe pump circulates temperature-regulating fluid through the rover's body with 200 feet of tubes.
.... On Mars, the pump must run constantly, and if it failed, the rover would die." ohmy.gif

Oh, great. One more failure mode to worry about.

Posted by: centsworth_II May 23 2011, 05:20 AM

I get the impression that following the MSL's progress through it's mission will have the same temporal feeling as following the MER missions. The MSL will not move from spot to spot any faster. And there will always be energy restraints placed on how fast science can be done at any one spot. Of course MSL can move into much more challenging terrain than MER and do a lot more science, but I think we will experience the same level of "are we there yet" and "when will we be moving on" feelings as we do with MER.

MSL produces about four times as much energy as the MERs, but it weighs over four times as much. The science payload, I'm sure, uses at least four times as much energy as the MER payload on average. So the energy budget restrictions for roving and science should be about the same for MSL as for MER.


http://www.usatoday.com/tech/science/space/2008-04-13-mars_N.htm

Posted by: elakdawalla Jul 22 2011, 08:09 PM

This topic has been split at the point that the downselection to Gale was made. http://www.unmannedspaceflight.com/index.php?showtopic=7020

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