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#1220 by hop on 14 Sep, 2014 23:15
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Bu the wheel situation is still very dire. Remember they have to go another 8 km compared to the 10 they have done already, over much rockier ground.
Rockier ground by itself is not the problem, it specifically has to be strong, immobile, pointy rocks. Stuff like Yellowknife bay is much less of a concern, and much of the upcoming terrain should be more like that. Parhump Hills certainly looks that way http://mars.jpl.nasa.gov/msl-raw-images/msss/00748/mcam/0748ML0032240050206004E01_DXXX.jpg
Emily Lakdawalla's post one the wheel wear issue (http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html) quotes an estimated 30-40 km on flagstone-ish terrain. Since they have tested multiple wheels to destruction, they should have a pretty good handle on the rate in various kinds of terrain. -
#1221 by meekGee on 14 Sep, 2014 23:16
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Thanks Dalhousie.
It still sounds like they are bemoaning the unchangeable.
The rover is headed uphill, and is drilling where there is an interesting spot.
Can't drive any faster...
"Lack of focus" suggests that the reviewer thinks there's something else that can be done. As in "stop getting distracted by taking pictures of Phobos"... But since this is not the case, and the reviewer does not have a better drive plan, I don't see his point.
If anything, they are being disciplined, not taking samples just in order to generate vanity data, and keeping their eye on the goal.
Suppose you sent a probe to a comet, and due to a thruster problem, the trip took 2x as long... Would you bemoan the lack of data while enroute?
I think the review panel were very careful not to bemoan the unchangeable. They very carefully (IMHO) did not mention the past. The criticisms are all on the future plans. E.g. once they get to the lower part Mt Sharp they are only going to do eight analyses in the next two years? Really? In the most interesting part of the succession? With CheMin and SAM still capable of 60 or more analyses after than?
Keep in mind that the wheel situation is probably much worse than the brave words from JPL. A contradiction in the press conference shows it up. While talking about the eight km drive over the next two years climbing through much rockier terrain than hitherto, they said that they had shortened the next segment by 100 m to save wear on the wheels. If the wheel situation is so bad that a 100 m shortening of the route is significant, planning on another 8 km seems rather optimistic.
My question was - what are the alternatives?
The distance they can cover in the next two years is fixed. The route is pretty much agreed on.
Should they drill and take more samples just because if the wheels die early, at least the magazine would be spent, so to speak?
What they are saying is - they'll drill and sample according to the scientific worth of the terrain, and that's the best they can do. If they wheels last long enough, then at least they'll have more samples to take.
But wasting them early actually sounds a bit panicky to me. Imagine the red faces if the wheels do hold, but they're out of ammo since they wanted to look good? -
#1222 by IslandPlaya on 14 Sep, 2014 23:44
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The wheels wont die early, especially now JPL are aware of the concern.
They are saving the sample wheel because they know that once they reach Mt. Sharp they can get samples from obviously different eras on Mars.
In Grotzinger we trust!
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#1223 by Dalhousie on 15 Sep, 2014 08:17
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Thanks Dalhousie.
It still sounds like they are bemoaning the unchangeable.
The rover is headed uphill, and is drilling where there is an interesting spot.
Can't drive any faster...
"Lack of focus" suggests that the reviewer thinks there's something else that can be done. As in "stop getting distracted by taking pictures of Phobos"... But since this is not the case, and the reviewer does not have a better drive plan, I don't see his point.
If anything, they are being disciplined, not taking samples just in order to generate vanity data, and keeping their eye on the goal.
Suppose you sent a probe to a comet, and due to a thruster problem, the trip took 2x as long... Would you bemoan the lack of data while enroute?
I think the review panel were very careful not to bemoan the unchangeable. They very carefully (IMHO) did not mention the past. The criticisms are all on the future plans. E.g. once they get to the lower part Mt Sharp they are only going to do eight analyses in the next two years? Really? In the most interesting part of the succession? With CheMin and SAM still capable of 60 or more analyses after than?
Keep in mind that the wheel situation is probably much worse than the brave words from JPL. A contradiction in the press conference shows it up. While talking about the eight km drive over the next two years climbing through much rockier terrain than hitherto, they said that they had shortened the next segment by 100 m to save wear on the wheels. If the wheel situation is so bad that a 100 m shortening of the route is significant, planning on another 8 km seems rather optimistic.
My question was - what are the alternatives?
The distance they can cover in the next two years is fixed. The route is pretty much agreed on.
Should they drill and take more samples just because if the wheels die early, at least the magazine would be spent, so to speak?
What they are saying is - they'll drill and sample according to the scientific worth of the terrain, and that's the best they can do. If they wheels last long enough, then at least they'll have more samples to take.
But wasting them early actually sounds a bit panicky to me. Imagine the red faces if the wheels do hold, but they're out of ammo since they wanted to look good?
That’s a good comment. It is important not to panic, but at the same time be aware that the mission could end any time. Especially given the state of the wheels.
Curiosity’s instruments are of two types, those that are capable of effectively indefinite use (MastCam, MAHLI, DAN, RAD, ChemCam, REMS, APXS) and those with a limited number of runs (CheMin, SAM).
SAM has 74 sample cups for surface samples. These are composed of three main kinds: 59 quartz cups, 9 wet chemistry cups, and 6 calibration cups. http://www.planetary.org/blogs/emily-lakdawalla/2012/curiosity-instrument-sam.html CheMin carries 27 reusable sample cells and 5 permanent reference standards, the cells can be reused two to three times, for a nominal 74 analyses (presumably to match SAM) http://msl-scicorner.jpl.nasa.gov/Instruments/CheMin/.
While all the instruments are useful, in some ways SAM and CheMin are the key to the mission. SAM is the only instrument that can tell us about organics and also the isotope composition of oxygen, hydrogen, carbon, and nitrogen in carbonated and hydrated rocks. Stable isotope take is very important for environment reconstruction. CheMin supplies the only good mineralogy data for the mission via XRD (and also incidentally the best mineralogy information we have from the surface of Mars) and the best geochemistry (although ChemCam and the APXS do as well).
To date three geological samples have been analysed and published by SAM and CheMin. A fourth is onboard, and may have been analysed already, but results are not yet been published. That is a very poor productivity for the two year primary mission. A fifth sample is supposed to be collected in a few weeks”. That leaves 54 unused SAM sample cups and 22 unused CheMin sample cells.
The wet chemistry SAM cells are being saved for organic rich samples, should these be found. Assuming of course they are still operation given leaks, but that’s another story.
The first mission extension (EM1 proposes to sample another three or four sites from the three major units in the lower part of the Mt Sharp succession – Paintbrush (the oldest unit seen, possibly representing the pre-Gale bedrock, although this has to be tested), then Hematite (full of iron oxides), a clay unit and then a sulphate unit. Two samples are proposed from each of Paintbrush, Hematite, and sulphate units, one two or three from the clays, for a total of nine. There for at the end of the proposed two year extended mission there will still be 43 unused SAM and 13 unused CheMin samples containers. More left over than have been used to date.
I think there are three factors to consider when looking ahead at future usage of CheMin and SAM. 1) geological units are often heterogeneous, so it makes sense to get multiple samples from the same lithology, at least three. It's not a question of panicing but getting representative data. 2) The most interesting targets are the lower part of the Mt Sharp succession. They are the reason Gale Crater was chosen for the landing site. There it makes sense to collect the most detailed sample data from it. 3) We don’t know how long the wheels will hold out, lasting to the end of EM1 may be optimistic, given the rougher, steeper and rockier terrain. So it makes sense to maximise use of the tools with the most limited future opportunities.
So the number of analyses could be doubled, for a total of 18, and still leave 34 SAM and four CheMin sample containers unused for EM2, if the rover is still mobile. Also of course the CheMin sample containers can be reused 2-3 times, with minimal degradation of analytical quality, so that CheMin can still effectively match SAM sample for sample. So that we could even triple the number of samples to 27 and still have some in reserve
So yes, sampling can be doubled or tripled without panicing and leaving none for the next extension. Even when all onboard processing capability is gone there would still be Mastcam, MAHLI, APXS, Chemcam and DAN to continue to shed light on the geology
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#1224 by Dalhousie on 15 Sep, 2014 08:32
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The wheels wont die early, especially now JPL are aware of the concern.
They are saving the sample wheel because they know that once they reach Mt. Sharp they can get samples from obviously different eras on Mars.
In Grotzinger we trust!
But there is the rub.
The JPL response has basically gone from "It's not a problem, why is everyone making a fuss?" to It's a problem, but we are managing it by driving backwards and selecing the route carefully" to We are managing it by shortening the route by a kilometre"
So despite their best efforts the wheels are getting worse and, while they will probably hold for a bit longer it is very questionable whether they will make another 8 km. Remember the terrain is steeper and rockier than anything seen to date.
Of course the planners are it a cleft stick here. they have had to drive all this way for the landing site, despite the wheel damage, because lower Mt Sharp is where the good science is. They have to drive 8 km to go through the entire lower stratigraphy - the clays, sulphates, haematite etc. There isn't much choice for them.
The problem is they are not maximising science in the process. They missed some interesting targets on the way here, and in the next two years they are looking at only another eight or nine samples under current plans. That leaves 78% of their analytical capability unused at a point when there is a real risk that the rover won't be drivable on the slopes of Mt Sharp.
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#1225 by meekGee on 15 Sep, 2014 10:28
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Yup, but given all of the above, we're now talking about risk management under very uncertain conditions.
That's not quite "lack of scientific focus", is it?
The PI decided that on the terrain reachable in the next two years, doing more than 8 drills will not add much science value. (Unless they find something new of course)
Meandering on the way up and stopping at extra points would have been "erring on the side of lack of focus".
Honestly, the right thing to do would have been to point out constructive alternatives, not just count samples.
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#1226 by Dalhousie on 15 Sep, 2014 11:39
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Yup, but given all of the above, we're now talking about risk management under very uncertain conditions.
That's not quite "lack of scientific focus", is it?
The PI decided that on the terrain reachable in the next two years, doing more than 8 drills will not add much science value. (Unless they find something new of course)
Meandering on the way up and stopping at extra points would have been "erring on the side of lack of focus".
Honestly, the right thing to do would have been to point out constructive alternatives, not just count samples.
It's not merely my opinion, it's the opinion of the review. They considered only eight more measurements to be a poor return. Covering great distances is meaningless unless you do the science.
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#1227 by veblen on 15 Sep, 2014 13:43
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Okay the science team knows from a couple of the instruments like ChemCam and APXS that the rocks are the same composition for the last several kms driven. Sampling the same stuff over and over, what is to be gained from that when they know the really interesting formation is at least as far as Pahrump Hills/base of Mt. Sharp?
I am not impressed with the review, just sounded like they can't handle the damage to the wheels and used at as a platform to bellyache about "flagship" this and that and Grotzinger was absent from multiple meetings. Shouldn't one meeting suffice?
Plus the review panel does not look back - because that would mean discussing the inconvenient truth that the primary science goals for MSL were attained at Yellowknife Bay. Hard to kvetch about that. -
#1228 by hop on 15 Sep, 2014 21:10
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The JPL response has basically gone from "It's not a problem, why is everyone making a fuss?" to It's a problem, but we are managing it by driving backwards and selecing the route carefully" to We are managing it by shortening the route by a kilometre"
This does not appear to be an accurate summary of the actual situation. From everything I've heard, once they dug into the problem the wheel damage has followed their predictions pretty well. They are obviously taking every opportunity they can to maximize the life, including route changes and driving strategies.
So despite their best efforts the wheels are getting worse and, while they will probably hold for a bit longer it is very questionable whether they will make another 8 km.
This is pretty typical JPL... no one catches every problem in advance, but once they do find one, they analyze the heck out of it.QuoteRemember the terrain is steeper and rockier than anything seen to date.
As noted in my earlier post, rockier alone doesn't necessarily mean worse. They have the ability to identify bad terrain from orbital data, and this has proven pretty reliable so far. -
#1229 by Dalhousie on 15 Sep, 2014 22:22
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Okay the science team knows from a couple of the instruments like ChemCam and APXS that the rocks are the same composition for the last several kms driven. Sampling the same stuff over and over, what is to be gained from that when they know the really interesting formation is at least as far as Pahrump Hills/base of Mt. Sharp?
What's past is history, but since you raise it, there have been a number of very interesting rocks that could have done with more analysis, for example Turkey screatch rock, which didn't even get the AXPS or Chemcam treament, desite being the only porphyritic rock we have seen anywhere on Mars. Because it was loose it could not have been drilled and thus not able to be analysed by CheMin.
There have been a few texturally different sedimentary rocks that would have been worth looking at in more detail at the other waypoints. Remember that Chcham and APXS both give only chemistry. One of the weaknesses of the Curiosity design is that it has no equivalent drive by or contact instrument for minerally (unlike the MERs which have the MiniTES spectrometer). Rocks can have similar chemistries but different mineralogy.
And of course the only way that organic compounds can be detected is with SAM. Having come up with a hypothesis for the preservation of organics in the regolith back at Glenelg, they have driven past several opportunities to test that hypothesis. This would be useful to know prior to the lower succession of Mt Sharp. It would be a shame with only eight samples planned that they ended up taking the wrong places on the basis of an untested hypothesis.QuoteI am not impressed with the review, just sounded like they can't handle the damage to the wheels and used at as a platform to bellyache about "flagship" this and that and Grotzinger was absent from multiple meetings. Shouldn't one meeting suffice?
The review is biggest criticism was about the lack of science, not the wheel damage. Wheel damage wasn't mentioned.
And yes, this is the senior review, which is about the amount of funding the mission should get over the next two years. The PI should have it as a priority. Not turning up is rude, arrogant and demonstrates, as the senior reviewer said, a "too big to fail" mentality.QuotePlus the review panel does not look back - because that would mean discussing the inconvenient truth that the primary science goals for MSL were attained at Yellowknife Bay. Hard to kvetch about that.
The review panel was for the extended mission, not to reflect on past glories. It's poor return for the EM1 phase that concerned them.
But since you raise it, what's inconvenient about the success at Yellowknife Bay? It was pure luck. However it is questionable whether the science goals were fully meant there. From the launch media kit the science goals were:
1) Assess the biological potential of at least one target environment by determining the nature and inventory
of organic carbon compounds, searching for the chemical building blocks of life and identifying features that may record the actions of biologically relevant processes.
At best only partially achieved at Yellowknife Bay given the problematic of organic detection with SAM at the site due to contamination and the interaction with soil perchlorate.
2) Characterize the geology of the rover’s field site at all appropriate spatial scales by investigating the chemical, isotopic and mineralogical composition of surface and near-surface materials and interpreting the processes that have formed rocks and soils.
Achieved
3) Investigate planetary processes of relevance to past habitability (including the role of water) by assessing
the long timescale atmospheric evolution and determining the present state, distribution and cycling
of water and carbon dioxide.
Achieved in part.
4) Characterize the broad spectrum of surface radiation, including galactic cosmic radiation, solar proton events and secondary neutrons.
Achieved.
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#1230 by Dalhousie on 15 Sep, 2014 22:35
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The JPL response has basically gone from "It's not a problem, why is everyone making a fuss?" to It's a problem, but we are managing it by driving backwards and selecing the route carefully" to We are managing it by shortening the route by a kilometre"
So despite their best efforts the wheels are getting worse and, while they will probably hold for a bit longer it is very questionable whether they will make another 8 km.
This does not appear to be an accurate summary of the actual situation. From everything I've heard, once they dug into the problem the wheel damage has followed their predictions pretty well. They are obviously taking every opportunity they can to maximize the life, including route changes and driving strategies.
That's the story they are putting about, but I don't believe it for one moment. Prior to launch the notion was to drive 30 km or more in the primary mission. I find it hard to believe that would have been considered had the sort of damage seen been expected.QuoteThis is pretty typical JPL... no one catches every problem in advance, but once they do find one, they analyze the heck out of it.
It's typical of everyone doing a planetary mission, not a unique property of JPL.QuoteRemember the terrain is steeper and rockier than anything seen to date.
QuoteAs noted in
my earlier post, rockier alone doesn't necessarily mean worse. They have the ability to identify bad terrain from orbital data, and this has proven pretty reliable so far.
As a general rule, rockier is worse for wheel damage. So are slopes. Rocky slopes are worse. Rocky rough slopes, where the roughness limits the choices as to which route can be taken, are the worst of all. Curiosity has all three ahead of it.
There is some ability to identify surface roughness from orbit, especially when the terrain ahead is similar to what has been traversed. But the terrain ahead of Curiosity is nothing like what has been traversed so far. However the surface roughness and rockiness predictive ability of HiRISE with it's 30 cm resolution is very limited, as the problem appears to be small sharp rocks in the cm to 10 cm range. -
#1231 by IslandPlaya on 15 Sep, 2014 23:03
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Your quoting is broken, please fix it.
Curiosity has no problem with rocky terrain. It does however have a problem with a particular terrain which has many sharp edges.
The terrain is changing, maybe this will be more/less of a problem.
Exciting, init?
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#1232 by veblen on 15 Sep, 2014 23:59
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Okay the science team knows from a couple of the instruments like ChemCam and APXS that the rocks are the same composition for the last several kms driven. Sampling the same stuff over and over, what is to be gained from that when they know the really interesting formation is at least as far as Pahrump Hills/base of Mt. Sharp?
What's past is history, but since you raise it, there have been a number of very interesting rocks that could have done with more analysis, for example Turkey screatch rock, which didn't even get the AXPS or Chemcam treament, desite being the only porphyritic rock we have seen anywhere on Mars. Because it was loose it could not have been drilled and thus not able to be analysed by CheMin.
There have been a few texturally different sedimentary rocks that would have been worth looking at in more detail at the other waypoints. Remember that Chcham and APXS both give only chemistry. One of the weaknesses of the Curiosity design is that it has no equivalent drive by or contact instrument for minerally (unlike the MERs which have the MiniTES spectrometer). Rocks can have similar chemistries but different mineralogy.
And of course the only way that organic compounds can be detected is with SAM. Having come up with a hypothesis for the preservation of organics in the regolith back at Glenelg, they have driven past several opportunities to test that hypothesis. This would be useful to know prior to the lower succession of Mt Sharp. It would be a shame with only eight samples planned that they ended up taking the wrong places on the basis of an untested hypothesis.QuoteI am not impressed with the review, just sounded like they can't handle the damage to the wheels and used at as a platform to bellyache about "flagship" this and that and Grotzinger was absent from multiple meetings. Shouldn't one meeting suffice?
The review is biggest criticism was about the lack of science, not the wheel damage. Wheel damage wasn't mentioned.
And yes, this is the senior review, which is about the amount of funding the mission should get over the next two years. The PI should have it as a priority. Not turning up is rude, arrogant and demonstrates, as the senior reviewer said, a "too big to fail" mentality.QuotePlus the review panel does not look back - because that would mean discussing the inconvenient truth that the primary science goals for MSL were attained at Yellowknife Bay. Hard to kvetch about that.
The review panel was for the extended mission, not to reflect on past glories. It's poor return for the EM1 phase that concerned them.
But since you raise it, what's inconvenient about the success at Yellowknife Bay? It was pure luck. However it is questionable whether the science goals were fully meant there. From the launch media kit the science goals were:
1) Assess the biological potential of at least one target environment by determining the nature and inventory
of organic carbon compounds, searching for the chemical building blocks of life and identifying features that may record the actions of biologically relevant processes.
At best only partially achieved at Yellowknife Bay given the problematic of organic detection with SAM at the site due to contamination and the interaction with soil perchlorate.
2) Characterize the geology of the rover’s field site at all appropriate spatial scales by investigating the chemical, isotopic and mineralogical composition of surface and near-surface materials and interpreting the processes that have formed rocks and soils.
Achieved
3) Investigate planetary processes of relevance to past habitability (including the role of water) by assessing
the long timescale atmospheric evolution and determining the present state, distribution and cycling
of water and carbon dioxide.
Achieved in part.
4) Characterize the broad spectrum of surface radiation, including galactic cosmic radiation, solar proton events and secondary neutrons.
Achieved.
Yellowknife Bay was not pure luck (MRO images/data to work from prior to landing) and inconvenient for the review panel in that the mission science goals achieved at that location, well it's hard to complain about that, right? Anyway, most important thing MSL received funding for extended mission. -
#1233 by Dalhousie on 16 Sep, 2014 00:39
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Curiosity has no problem with rocky terrain. It does however have a problem with a particular terrain which has many sharp edges.
Rocky terrain generally comes with sharp edges, especially on Mars. Plenty of sharp edges in Gusev crater for example with ventefacts cut into basalt. Likewise Ares Vallis, Chryse and Utopia.QuoteThe terrain is changing, maybe this will be more/less of a problem.
Almost certainly more of a problem. the only way it would be rest of a rpblem is if the rocks are unsually soft and/or friable.QuoteExciting, init?
Sure is
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#1234 by Dalhousie on 16 Sep, 2014 00:51
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Yellowknife Bay was not pure luck (MRO images/data to work from prior to landing)...
It was most certainly pure luck that it was done at Yellowknife it because Curiosity could have landed anywhere in the landing ellipse.Quoteand inconvenient for the review panel in that the mission science goals achieved at that location, well it's hard to complain about that, right?
Not even wrong. 1) The review panel was not there to review past achievements, 2) did not dispute past achievements beyond noting that they were rather rubbery and generic (which is fairly obvious), 3) past achievements are no assurance of future performance (in this case uninspiring), and 4) it was there to review future plansQuoteAnyway, most important thing MSL received funding for extended mission.
Indeed, but the proposed work program is rather disapointing given the capabilities, as the review panel rightly pointed out, and has also rightly recommended that this be reconsidered. -
#1235 by hop on 16 Sep, 2014 03:20
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That's the story they are putting about, but I don't believe it for one moment.
You are certainly entitled to your opinion, but it appears to be contradicted by the people who spent a whole lot of time actually working on the problem.QuotePrior to launch the notion was to drive 30 km or more in the primary mission. I find it hard to believe that would have been considered had the sort of damage seen been expected.
I'm not sure why you are bringing up pre-launch estimates. There is no question that this kind of damage was not expected pre-launch. I'm talking about the testing and analysis done after the problem was recognized. The statements I've seen are that the ongoing damage has been consistent with those results.QuoteAs a general rule, rockier is worse for wheel damage. So are slopes. Rocky slopes are worse. Rocky rough slopes, where the roughness limits the choices as to which route can be taken, are the worst of all. Curiosity has all three ahead of it.
Your "general rule" appears to conflict with statements of the people who actually operate the vehicle. Specific types of rocky terrain are worse.QuoteThere is some ability to identify surface roughness from orbit, especially when the terrain ahead is similar to what has been traversed. But the terrain ahead of Curiosity is nothing like what has been traversed so far. However the surface roughness and rockiness predictive ability of HiRISE with it's 30 cm resolution is very limited, as the problem appears to be small sharp rocks in the cm to 10 cm range.
You are making a lot of assumptions. -
#1236 by Dalhousie on 16 Sep, 2014 03:57
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That's the story they are putting about, but I don't believe it for one moment.
You are certainly entitled to your opinion, but it appears to be contradicted by the people who spent a whole lot of time actually working on the problem.
It goes against the pangloss media coverage, but a lot of people behind the scenes are concerned.QuoteQuotePrior to launch the notion was to drive 30 km or more in the primary mission. I find it hard to believe that would have been considered had the sort of damage seen been expected.
I'm not sure why you are bringing up pre-launch estimates. There is no question that this kind of damage was not expected pre-launch. I'm talking about the testing and analysis done after the problem was recognized. The statements I've seen are that the ongoing damage has been consistent with those results.
I brought up prelaunch expectations to show the scale of the problem. We agree there is a problem, and people are doing their best to work with itQuoteQuoteAs a general rule, rockier is worse for wheel damage. So are slopes. Rocky slopes are worse. Rocky rough slopes, where the roughness limits the choices as to which route can be taken, are the worst of all. Curiosity has all three ahead of it.
Your "general rule" appears to conflict with statements of the people who actually operate the vehicle. Specific types of rocky terrain are worse.
Of course some terrains are worse than others. Angularity, rock hardness, rock size, roughess and slope are all factors. Which is why picking routes as helped. This will continue. But if you think that things will get better the closer they get to Mt Sharp and start moving up the slope you may be surprised. I would be amazed if anyone in the Curiosity team thinks this. I certainly have seen not statements that indicates that they do.QuoteQuoteThere is some ability to identify surface roughness from orbit, especially when the terrain ahead is similar to what has been traversed. But the terrain ahead of Curiosity is nothing like what has been traversed so far. However the surface roughness and rockiness predictive ability of HiRISE with it's 30 cm resolution is very limited, as the problem appears to be small sharp rocks in the cm to 10 cm range.
You are making a lot of assumptions.
Not assumptions, a knowledge of how the process works and the capabilities and limitations of interpreting remotely sensed data.
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#1237 by JohnFornaro on 24 Sep, 2014 01:14
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September 11, 2014
RELEASE 14-245
NASA’s Mars Curiosity Rover Arrives at Martian Mountain
NASA's Mars Curiosity rover has reached the Red Planet's Mount Sharp...
You know how real estate agents use some pretty broad descriptions to describe desireable neighborhoods? That's how I read the headline above.
Even to claim that they have reached the first outcrop of the Mt Sharp succession is questionable.
But still, they've been driving around for two years, and that in and of itself is pretty cool. True, they've taken only a few samples, and for some reason they are slow on publishing the info on the samples they have taken.
The thing that most struck me, in a positive way, was the image of how they are assessing their future path. If you're playing with your remote controlled rover in the back yard, or at the beach, it's really easy to walk over and get it unstuck. On Mars, not so much.
So I have an intuitive and honest appreciation for the work that goes on in analyzing the terrain, and plotting the next traverse, particularly since since the wheels turned out to be so fragile.
Still, ya gotta wonder at the decision making proces:The first leg of the Curiosity traverse was away from Mt Sharp to a location called Glenelg...
I'm not the author of this comment:
It was unclear from both the proposal and presentation that the Prime Mission science goals had been met.
I thought that the mission had already been deemed a succes? Somebody needs to make up their minds.
On the plus side, the rate of wheel deterioration and the number of samples which can yet be taken needs to be analyzed so as to come up with a rate of sampling which agrees with the expected decay. Which is a shorter way of saying what MeekGee said:My question was - what are the alternatives?
The distance they can cover in the next two years is fixed. The route is pretty much agreed on.
Should they drill and take more samples just because if the wheels die early, at least the magazine would be spent, so to speak?
What they are saying is - they'll drill and sample according to the scientific worth of the terrain, and that's the best they can do. If they wheels last long enough, then at least they'll have more samples to take.
But wasting them early actually sounds a bit panicky to me. Imagine the red faces if the wheels do hold, but they're out of ammo since they wanted to look good?
The truth of the matter is that there's criticism and praise, and that's just the way it goes. -
#1238 by robertross on 25 Sep, 2014 23:58
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09.25.2014
Source: Jet Propulsion Laboratory
NASA Rover Drill Pulls First Taste From Mars Mountain
NASA's Curiosity Mars rover has collected its first taste of the layered mountain whose scientific allure drew the mission to choose this part of Mars as a landing site.
Late Wednesday, Sept. 24, the rover's hammering drill chewed about 2.6 inches (6.7 centimeters) deep into a basal-layer outcrop on Mount Sharp and collected a powdered-rock sample. Data and images received early Thursday at NASA's Jet Propulsion Laboratory, Pasadena, California, confirmed success of this operation. The powder collected by the drilling is temporarily held within the sample-handling mechanism on the rover's arm.
"This drilling target is at the lowest part of the base layer of the mountain, and from here we plan to examine the higher, younger layers exposed in the nearby hills," said Curiosity Deputy Project Scientist Ashwin Vasavada of JPL. "This first look at rocks we believe to underlie Mount Sharp is exciting because it will begin to form a picture of the environment at the time the mountain formed, and what led to its growth."
After landing on Mars in August 2012 but before beginning the drive toward Mount Sharp, Curiosity spent much of the mission's first year productively studying an area much closer to the landing site, but in the opposite direction. The mission accomplished its science goals in that Yellowknife Bay area. Analysis of drilled rocks there disclosed an ancient lakebed environment that, more than three billion years ago, offered ingredients and a chemical energy gradient favorable for microbes, if any existed there.
From Yellowknife Bay to the base of Mount Sharp, Curiosity drove more than 5 miles (8 kilometers) in about 15 months, with pauses at a few science waypoints. The emphasis in mission operations has now changed from drive, drive, drive to systematic layer-by-layer investigation.
"We're putting on the brakes to study this amazing mountain," said Curiosity Deputy Project Manager Jennifer Trosper of JPL. "Curiosity flew hundreds of millions of miles to do this."
Curiosity arrived Sept. 19 at an outcrop called "Pahrump Hills," which is a section of the mountain's basal geological unit, called the Murray formation. Three days later, the rover completed a "mini-drill" procedure at the selected drilling target, "Confidence Hills," to assess the target rock's suitability for drilling. A mini-drill activity last month determined that a rock slab under consideration then was not stable enough for full drilling, but Confidence Hills passed this test.
The rock is softer than any of the previous three targets where Curiosity has collected a drilled sample for analysis.
Between the mini-drill test and the sample-collection drilling, researchers used tools on Curiosity's mast and robotic arm for close-up inspection of geometrically distinctive features on the nearby surface of the rock.
These features on the Murray formation mudstones are the accumulations of resistant materials. They occur both as discrete clusters and as dendrites, where forms are arranged in tree-like branching. By investigating the shapes and chemical ingredients in these features, the team hopes to gain information about the possible composition of fluids at this Martian location long ago.
The next step will be to deliver the rock-powder sample into a scoop on the rover's arm. In the open scoop, the powder's texture can be observed for an assessment of whether it is safe for further sieving, portioning and delivery into Curiosity's internal laboratory instruments without clogging hardware. The instruments can perform many types of analysis to identify chemistry and mineralogy of the source rock.
http://mars.jpl.nasa.gov/msl/news/whatsnew/index.cfm?FuseAction=ShowNews&NewsID=1720
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#1239 by robertross on 25 Sep, 2014 23:59
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Resistant Features in 'Pahrump Hills' Outcrop
This image from the Mars Hand Lens Imager (MAHLI) camera on NASA's Curiosity Mars rover shows an example of a type of geometrically distinctive feature that researchers are examining at a mudstone outcrop at the base of Mount Sharp.
These features on the "Pahrump Hills" outcrop are accumulations of erosion-resistant materials. Similar-appearing features on Earth form when shallow bodies of water begin to evaporate and minerals precipitate from the concentrated brines.
The width of the image covers about nine-tenths of an inch (2.2 centimeters) of the rock surface. This is a merged-focus image product combining information from multiple MAHLI images taken on Sept. 23, 2014, during the 758th Martian day, or sol, of Curiosity's work on Mars.
MAHLI was built by Malin Space Science Systems, San Diego. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover.
Image Credit: NASA/JPL-Caltech/MSSS
http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=6615
