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NASA to revise Mars program
Cugel
post Jul 6 2006, 02:00 PM
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http://www.space.com/news/060706_mars_report.html

quote:

The review group also flagged “the extraordinary resilience” of the Spirit and Opportunity rovers still at work on the red planet. Success of that Mars machinery “strongly suggests that a prudent, risk-reduction strategy is to use their design as a basis for the proposed Mid Rovers,” the committee stated.

RIGHT!
Would you believe it. We're going to do it all over again!
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djellison
post Jul 6 2006, 02:54 PM
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Well - to be fair - your subject is a bit of gun-jumping. This report has suggested they SHOULD revise it....it's up to NASA to see if they take the advice and make those changes smile.gif

Doug
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Cugel
post Jul 6 2006, 03:10 PM
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Yeah, you're right Doug.

Still, it's a pretty good advise if you ask me.
Just imagine 8 or 9 MER rovers on Mars, concurrently.
I wonder what the boys and girls at JPL think of that....
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mcaplinger
post Jul 6 2006, 03:20 PM
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QUOTE (Cugel @ Jul 6 2006, 08:10 AM) *
Just imagine 8 or 9 MER rovers on Mars, concurrently.

We've debated this many times on this forum. Given the very limited ability of the MER system to land at interesting places, I'd wonder about the science return of this. Plus, it's become somewhat obvious that the mobility of the MER system in soft, sandy areas is pretty limited. Science advisory groups should be recommending science, not engineering solutions in search of problems.

Of course, they may not be talking about the MER EDL system but only about the rover proper. But that's a whole different set of engineering tradeoffs, and the resulting vehicle may look little like MER in the end. MER's heritage is in subsystems, not necessarily in the overall vehicle design.


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Bob Shaw
post Jul 6 2006, 03:28 PM
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QUOTE (mcaplinger @ Jul 6 2006, 04:20 PM) *
Of course, they may not be talking about the MER EDL system but only about the rover proper. But that's a whole different set of engineering tradeoffs, and the resulting vehicle may look little like MER in the end. MER's heritage is in subsystems, not necessarily in the overall vehicle design.


Perhaps also in terms of scale, cost, and expectations, too...

Bob Shaw


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Guest_Richard Trigaux_*
post Jul 6 2006, 04:09 PM
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QUOTE (mcaplinger @ Jul 6 2006, 03:20 PM) *
We've debated this many times on this forum. Given the very limited ability of the MER system to land at interesting places, I'd wonder about the science return of this. Plus, it's become somewhat obvious that the mobility of the MER system in soft, sandy areas is pretty limited. Science advisory groups should be recommending science, not engineering solutions in search of problems.


It is obvious that a lander cannot alway land on the right interesting places. But there are many interesting places, and, when the landing actually takes place, the science focus can change (as for Spirit). So we don't need 8 or 9 MERS, but hundreds...

So I think that what is interesting would be a rover with a much larger range capacity, say in the thousand kms.

Worse, the mobility of the MERS showed poor in sandy terrains (some metres per sol since Erebus, at the cost of maintaining a whole team and network to drive them), and this in terrains which were carefully choosen as flat lands, without large slopes and cliffs, not chaotic regions or heaps of large boulders or scoriaced lava flows.

So I think we need improved mobility rovers:

-much larger wheels
-ability to lift each wheel (out of a rock or sand trap)
-much more software for autonomous driving.
-improved terrain sensing, with some LIDAR or ultrasound 3D sensing (true 3D, not a stereo reconstruction)
-motors, joints, actuators... designed for a long duty
(this was already discussed somewhere)

Of course such a rover would be larger, but perhaps one larger rover would cost less that many small ones.
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ElkGroveDan
post Jul 6 2006, 04:57 PM
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QUOTE (mcaplinger @ Jul 6 2006, 07:20 AM) *
We've debated this many times on this forum. Given the very limited ability of the MER system to land at interesting places, I'd wonder about the science return of this.

If it included 8 or 9 ORBITERS as part of the deal, would that bring you on board? wink.gif


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ElkGroveDan
post Jul 6 2006, 05:00 PM
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QUOTE (Richard Trigaux @ Jul 6 2006, 08:09 AM) *
So I think we need improved mobility rovers:

-much larger wheels
-ability to lift each wheel (out of a rock or sand trap)
-much more software for autonomous driving.
-improved terrain sensing, with some LIDAR or ultrasound 3D sensing (true 3D, not a stereo reconstruction)
-motors, joints, actuators... designed for a long duty
(this was already discussed somewhere)

Don't forget the ability to disengage any one wheel.


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Guest_Myran_*
post Jul 6 2006, 06:00 PM
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In reply to some of the suggestions made here:

The 'Mid Rovers' are to be less complicated and less expensive than Opportunity and Spirit.

In short that they'll be MER's on a budget, it was mentioned that they might be more 'capable' though.

Without any firm plans I would take a guess this could mean other cameras, a CPU with more processing power and perhaps memory, a drill that can work on more rocky targets, and if im allowed to dream: A small but capable weather station.
The last one could answer a lot of questions, many of which have been asked here about wind directions, the dust devils, temperature, humidity, perhaps also give a clue on the speed of sand, frost in the night time etc etc. And it would not add that much data to be sent to Earth, should be less than what goes into one single image.
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mcaplinger
post Jul 6 2006, 06:51 PM
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QUOTE (ElkGroveDan @ Jul 6 2006, 09:57 AM) *
If it included 8 or 9 ORBITERS as part of the deal, would that bring you on board? wink.gif

Given fiscal realities, imagining 8 or 9 of anything is pretty much living in fantasyland at this point. It's important for somebody to live in fantasyland, I guess, but I've got real flight hardware to design and build, and I lose patience with science advisory groups pretending to understand engineering.


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Bob Shaw
post Jul 6 2006, 07:36 PM
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Skip all them instruments if you will - but give me a spade!

Bob Shaw


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djellison
post Jul 6 2006, 07:43 PM
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Come on then MC - what would you like to see flown smile.gif

Doug
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Guest_AlexBlackwell_*
post Jul 6 2006, 07:51 PM
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QUOTE (mcaplinger @ Jul 6 2006, 06:51 PM) *
Given fiscal realities, imagining 8 or 9 of anything is pretty much living in fantasyland at this point. It's important for somebody to live in fantasyland, I guess, but I've got real flight hardware to design and build, and I lose patience with science advisory groups pretending to understand engineering.

I agree, Mike. These groups, which some list under the category AFC (another freakin' committee!), often step over the line into mission design rather than program architecture.

I guess the flip side (engineers pretending to understand science) causes equal impatience :-) Though it is also true that this scenario happens far less often than yours. Most engineers wouldn't embarass themselves trying, and that's assuming that most actually care about the science.
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Cugel
post Jul 6 2006, 09:36 PM
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Let's not forget that MER was banking heavily on the extremely close opposition of 2003, which made it possible (just!) to use a cheap(ish) Delta-II booster. Delta-II's have become more expensive and Mars will not come as close, so I think any MER successor will fly on a Atlas-V or Delta-IV. This means a completely other mass budget and thus a completely different rover all together.
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djellison
post Jul 6 2006, 09:42 PM
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I can see where you are coming from.

Science Comittee's should outline the priority science, the order of how they'd like things to be investigated.

Engineers should then examine that, and propose a series of missions to do those investigations

Then politicians given them 10th as much money as any of it needs. wink.gif

BUT - Are the engineers going to be guilty of designing the things they WANT to design instead of the 'best' (be that quickest, cheapest or whatever ) way to go and do those investigations. That's the ever-present tensions - engineers and scientists, questions and answers, ying and yang blah blah blah

I think MER has produced an orgy or people wanting to reuse the platform, but even Squyres admits that it's not ideal. There's a certain fondness for the platform, a belief that because two of them have worked, that if you sent two more you would get another 2 x 800+ sols of exploration.

I think two of everything makes sense, historically it's made sense as well. Viking, Voyager, Mariner, Viking, MER. I'm dissapointed that NH2 was not selected, and I'd have thought that an MSL2 would have made quite a lot of sense as well....but as ever, the money just isn't there.

There are situation when many copies of a vehicle make sense. Comms sats, weather sats, and obviously something like a netlander mission would justify many copies of the same probe...ditto impactors etc.

But more MER's, 5,6 years after they started building the first two, wouldn't make as much sense as say, investing the same cash in doing 2 MSL's.

The current problem I guess is that we have a load of questions, but don't really know where to go to get the answers.

Doug
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