I was just wondering about this, they have test rovers at JPL, which will eventually not be needed, they have a Proven EDL system and they have a few sites which were still MER rated (although I would like to see the one featured in Steve's book Roving Mars, where they land in Valles Marineris (I think that was right one of the Valles anyway) (solar power would suck though..) What would be the chances of using all the materials we already have and launching a new MER or pair of MER's in 2007?

They could upgrade some of the payload, based on results from the MER's data, must be something they wished they had.?

Just wondered.

How much would this cost?

It's impossible.
The MER rovers were optimized for a boeing Delta-2 rocket and up until 2018 the coming Mars oppositions will be so bad that the Delta-2 can't lift the mass of a MER rover to Mars. Using another booster will be very costly.

Sorry.

Thanks, however if and I know this is a big if the Falcon launch goes well, wonder if they would have a large enough launch vehicle in time for 2007

I strongly sponsorize this idea!
If a laucher is available, a relatively low-cost MER mission in Valles Marineris would be simply fantastic!

...And it's very hard to send to space equipment already used for testing. During the old days, JPL wanted also to use its spare Viking Lander on a new Mars mission that could have been sent in 1984 (dubbed "Viking III") with flexible crawl devices in place of the footpads, to gain some mobility... The mission was to use a direct entry on Mars, much like Pathfinder's and MER's (it was those preliminary entry studies that were used when the MESUR/pathfinder project begun...).
Finally there was no more budget for Viking III because of the launching cost... But also the VL s/c would have to be entilely dismantled, all s/c parts tested back and improved to be space-proof again, and rebuilt ! Unlike the 2001 Mars Lander, the spare VL lander was not shelved within a "space-clean" environment...
The same technical problems would arise for a "MER III"...

The problems are:

(1) The MERs, unmodified, simply can't carry that many scientifically cost-effective science instruments. Their goal was to settle once and for all the question of whether ancient Mars had significant amounts of liquid water on its surface, which they did. There is that proposal (which JPL is still close-mouthed about) to modify a MER into a cut-price, scientifically inferior version of MSL ( http://www.lpi.usra.edu/meetings/lpsc2005/pdf/2219.pdf ) -- but this would take major modification. As they now stand, the instruments that could be added on could not actually ingest and grind up samples for a detailed search for trace organic compounds, which is now the next important phase of Mars exploration. You could add some things like a LIBS or a Raman spectrometer -- at the cost of removing some of the existing instruments -- but their usefulness by themselves is limited.

(2) You still have the serious problem of the MER landing system's extreme vulnerability to horizontal crosswinds -- which is what finally ruled out at least two landing sites in the bottom of Valles Marineris which would otherwise almost certainly have been picked for MER-A. As things are, it barely survived its landing in the less windy Gusev. To solve this, you've got to switch all the way over to a full-blown soft-landing system with throttleable liquid rockets directed by sophisticated radar -- but if you're going to make that sort of radical addition to an MER, why not go further and land an MSL (or some scientifically intermediate class of rover)?

The two engineering models sat on the ground here on earth have probably covered a LOT more ground than the ones on mars - they're probably very tired anyway.

I asked Steve about this in the Q'n'A and he believes it would be hard to do a third MER inside a Mars Scout budget of say $400M

Doug

The original mission cost almost $800m, they have the design down, they have the parachute design down (which cost a lot to test referring to Roving Mars) all of the major cost points listed in Roving Mars have already been covered, I think one MER would have been in the ball park of $500m but the second was able to be done with $300m
Surely all of the parts for the MER's themselves dont cost $100m and a suitable launch vehicle I am sure could be found, In Steve's Book he mentioned the option of using Enterprise classed mission to launch a MER at the start, Is that option still available or have we succumbed to the Faster, Better, Cheaper designs? I just think that in the next 6 years it is a little long to wait for another mobile vehicle, to continue the dream of Exploration of Mars, to keep the publics attention, nothing keeps the publics attention like a Rover, I highly doubt there will be as much attention for Phoenix, and then what launches in 2009? that has yet to be decided. I vote we send at least one more MER to MARS, if not only to keep and maintain the publics interest, (Free Food at Long John Silver's if a MER found evidence of an ancient sea, They did comply with their end of the bargain)

I know we found evidence of water and that question has been answered, but to what extent, the floor of valles marineris would be an AWESOME place to search.

Send another MER and lets keep "Roving Mars"

John Cooke

(1) The MER already can grind up samples and has done so many times. Surely it would not be impossible to modify the instrument arm so it could scoop up some of the RAT droppings and deliver them to a hopper somewhere on the "deck"? It would presumably be rather more difficult to find place for an anlyzer unit, but probably not impossible.

(2) The TIRS system could fairly easily be upgraded, for example to 3 pairs of slightly smaller engines which would give a lot more flexibility in the size and direction of the sideways "kick".

tty

What are you willing to drop to accomodate it in terms of volume, mass, power and data budget?

Doug

While there is certainly some science return that could be had from a third MER, it is also certainly not the platform for the best next mission. The engineering limits are severe, and it should be noted that Spirit's success was a big counter to plan and somewhat lucky. Spirit's first 120 days were almost scientifically worthless, and if it had landed far from hills (as most of its ellipse was), it might have been a bust -- lots of basalt ejecta as far as the eye can see. Spirit's success in finding water was (probably) irrelevant to the purpose the Gusev landing site was chosen. Overall, we had a grand total of one landing site that met the considerable engineering constraints and scientific interest. These landing sites were chosen from list ranked by estimated interest, and we can already see the dropoff from #1 to #2.

A program intended to "geomorphology" the death out of Mars's tropics, and maybe luck into discoveries by serendipity could be had from the MERs and undoubtedly turn up a few gems per every so many missions... but this looks to be a loser in terms of cost effective space science. A craft that had a broader instrument package OR fewer engineering constraints (a MER to Athabasca Valles or the bottom of the Valles Marineris) would be a lot more likely to be a winner.

If NASA/JPL had unlimited money, I'd say send another MER rover, but of course, it doesn't. Ultimately it is probably better to put the funds into a more capable platform, even if it does take longer.

Personally, I don't find grinding rocks all that interesting, except that there may be something hidden within, which hasn't obviously happened yet (depending on who you ask, I suppose). A MER with specifically biology-detecting instruments would be nice, but, you know, money. Go for the big rover that can do it all, I say.

I think that everybody wants to keep to be busy with Mars explorations for all-round years. Nobody wants to miss a gap of four years between 2008 (after Phonix) and 20011 that there were no land missions on Mars.

I seem important to keep the momentum of Mars Exploration in order to improve the knowledge and experience by the not missing years between 2008 and 2011. Sending a MER-C with the advantage of its present technology and some adjustments. These adjustments are to align to the MSL mission to explore and quantitatively assess Mars as a potential habitat for life, past or present.

The other important factor is the continuity of highly skilled personnel with mind, experience and knowledge that are oriented to Mars mission. If not, many will be leaving and later hiring will not be as good unless after a some time.

Hence, the MER-C would be an important exploration in order to improve the MSL's mission. The improvement is done with the experience and knowledge gain in order to make a much better investment on MSL. Hence it helps to NASA to gain four years of long term mission in sending a man to Mars.

Rodolfo

Thought I would get a poll started just to get a numerical gauge.

Also if anyone could ask their friends at JPL what exactly would be needed to send a MER C that would be great.

That's pretty tough. OK I'll bite

First - go after some "easy" targets to save mass and reduce power consumption.
Power
The power subsystem has proven to be much better than expected and although luck has played its part I think we could safely do the following:
Reduce Solar panel area by 20%, possibly 30%. Clearly we have more power during a 90day mission than is absolutely needed provided there is no major storm. Mission timing can ensure that the storm risk is very small. The cells on the rovers are very good by current commercial standards but the best on the market today are about 20% more efficient again (34% now vs 26.8% at best when the Rovers were built).
I've no numbers on the mass of the Solar panel arrays on the MER's but I seem to remember a number of 30W\kg ie, panel mass is ~4.5Kg and the saving would be 1kg.

Reduce battery mass by 25%. Current generation of battery technologies have twice the power storage density (250-350Whr/kg vs 100Whr/kg for the current MER's)
Saving 2.5kg?

Power Management and Distribution - MER was around 80-90% efficient @ 50W/kg. Estimate (in 2002) was 85-95% efficient @ 125W/kg by 2007. Should be able to shave off 1kg there by now.

Total saving on the Power system - 4.5kg

As a sanity check I've got an ESA document [ Lang ESA 2002 ] that seems to gravitate to 5W/kg total system power subsystem mass for solar power\LiIon systems. That could be 28kg total mass on MER and we should be able to save 20% ie. 5.5kg.

Add some extra RHU's to areas now known to be temperature risk spots. At 40g a pop we can certainly afford 2 or 3 to protect areas during deep sleep (such as the Mini-TES). Sensibly chosen these could make deep sleep the normal mode of operation and help bring the minimum power requirement for regular operation down to 300Watt hours per Sol provided we can save some more power(below).

So Saving 4.5kg should be manageable while still generating\storing > 2.5 times the minimum power needed for operations at the start of the mission.

Processing and Data Storage.
Update the CPU from a RAD6000 to a RAD750. The RAD6000 is rated @ 25MIPs with a peak power draw of 7.5 Watts. The 750 has a peak power draw of 5W @ 133Mhz yielding 240MIPS and far superior FP performance.

Those extra (and cheaper) MIPs should drop total daily power requirements by between 25Whr and 50Whr improving our safety margin. Replace the existing 256M flash with a couple of GB. Those extra MIPS could then be used to handle more advanced image processing in situ, buffer more data to optimise downlink windows and thereby save additional power on data transmission.

So far - we've only saved 4-4.5kg or so but we have an order of magnitude more CPU and storage capability. We also should have a rover that could handle much trickier terrain autonomously if some effort was put in to updating the flight software.

Additional instruments.
Mass Spectrometer Mars96\Beagle2 - 4.4kg total. 4Watts of power.
Atmospheric Pressure sensor - 16grammes, 36mW, <1Whr/Sol
Wind Sensor 30grammes. 200-600mW. 30grammes. 12Whr/Sol

One of these chirality detectors would be ideal but I've no idea how practical\heavy\power hungry they would be.

Helvik
Your inform is pretty interesting. Since, the year 2002 until now, the technology components needed for spacecraft has improved much!

Rodolfo

Why do you want to send a pressure and wind sensor?

Doug

Aren't they good for array power solar?

Rodolfo

Because they're cheap and the data is useful. The Mars atmospheric models are very heavily "under development" and any and all data that can be acquired should be, especially if they can be provided with such little mass. It probably wouldn't be a bad idea to try and bundle together a pressure\wind sensor\UV sensor with a dedicated low power omni directional transmitter and it's own path to the solar panels, that way you could have a little met station that would intentionally outlive the lander for a very long time.

They wont generate electricity if that's what you mean.

Doug

A little wind-catching device would have to generate SOME electricity (power, anyway).. whether it's enough to be useful depends on various factors, of course..

The mass involved would be much MUCH better used as more solar array, which you KNOW is going to generate power

As for the data, it's no really data we need is it? Hardly worth a whole new MER!

Doug

Maybe, with the aeoleans instruments will help MER to search for best places to clean her panel solar array. Otherwise, a new incorporated compressor instrument will puf off any dirty powders from solar arrays.

Rodolfo

Though there have been many rumors to the contrary, the current plan is to fly MSL in 2009. (I'm the systems engineer for the cameras for MSL, so I think I have some insight.) So this whole discussion is based on a flawed assumption.

Now that's the sort of comment I like to hear.

Happy days.

The point I was trying to make in the original comment is that you could save at least 4.5kg mass on the power system while still generating enough power to equal the existing MER's generation:consumption ratio. The whole point is to save mass that way.

The important extra instrument would be either a mass spectrometer or a dedicated chirality sensor (if such a beastie is possible in this sort of time frame). The Met instruments are cheap in terms of mass and power and so could be added while keeping the whole system under the original 185kg mass.

I disagree with the comment about whether this is data we really need - the atmospheric models need all the ground truth data they can get to improve them. Putting small cheap sensors like these on major landers should be mandatory (in my obviously very biased opinion).

Linking them to the solar arrays independantly of the main power system was just a thought to enable them to outlive the main rover and act as a long term stationary met station. These would draw a small but non negligable amount of power and certainly the little anemometer could never generate anything.

However mcaplingers comment on MSL puts it all to bed really, there is just no comparison between a MER-C of any description and an MSL.

Perhaps NASA could develop a "barebones" rover. Something modular and potentially upgradable? Something like a MER, or MSL, but with a "science module" on the front - they could put in different instrument sets for successive missions. It might be more expensive for one or two missions, but look at how much is spent currently. Each mission involves lots of new R&D to design a totally new robot.
If MER had been designed to be upgradable, maybe it could have a science module up front, which would currently incorporate an all-in-1 IDD. Where the IDD is stowed would be an analysis chamber instead, while the instrument arm would basically be a rock collector.

Just idle speculation, with no idea of how feasible it actually is.

mcaplinger Posted Yesterday, 10:13 PM

"Though there have been many rumors to the contrary, the current plan is to fly MSL in 2009. (I'm the systems engineer for the cameras for MSL, so I think I have some insight.) So this whole discussion is based on a flawed assumption. "

I am really glad, and if I could pick your brains a little bit that would be great, has there been any update on if they are going to launch 2 MSL's?

Do you have any updates on the SkyCrane ? has any work been done on testing it and is it among the 'final' ideas?

Will the MSL still be RTG powered?

When will the final decision be made on the exact launch date?

Thanks

John Cooke

I'm not at liberty to disclose anything that's not publically available. The stuff at http://marsprogram.jpl.nasa.gov/missions/future/msl.html is accurate so far I know: there's one MSL, the baseline EDL system is Skycrane, the baseline is RTG power, and the launch is in December 2009.

It's good to know that someone who is actually working on the MSL says it will launch in 2009. In a perfect world we'd have rovers all over Mars, or even people jumping around in the sand/dirt/whatever, but the world isn't quite perfect yet. I'm looking forward to the MSL - it has to give us even more insight to that odd red planet..

Keep up the good work, mcaplinger.

I think the MERs are bare bones rovers.

Thank you so much for your wonderful reply, good to know that we are still on track, I cannot wait now.

4 years isnt that long after all

hehe the way the MER's are going you never know we still may have them around!

Again many thanks for reassuring us and taking the time to post.

Hopefully with your wonderful Camera's and pictures we can let the very talented people on this board loose to provide wonderful panoramas!


John Cooke

We don't mind if you have to kill us after you tell us, honest! We can cope!

The trouble is that:

(1) The top-level analyses that Mars scientists now want to do -- primarily a search for trace organics, with more detailed mineralogy as a secondary goal -- can only be done by scooping up, ingesting and grinding samples, which the MERs were never designed to do. The "MER-C" about which we've heard nebulous hints from JPL would presumably do this -- but its ability to do so is clearly very seriously limited compared to MSL. (Less than half as big a total analytical payload; capable of processing only 9 samples as compared to about 50 for MSL.)

(2) It may well turn out to be worthwhile to send smaller rovers with more specialized analytical instruments to different parts of Mars to scout out especially organic-rich (or otherwise promising) landing sites for future sample-return missions -- but ONLY AFTER WE HAVE A BETTER IDEA WHAT THEY'LL BE LOOKING FOR. MSL's instruments (particularly its GCMS package, which is its central payload) are capable of very flexible searches for different kinds of compounds and minerals. AFTER its studies have given us some idea what sorts of interesting substances may actually exist on Mars, we can tailor more specialized and smaller instruments to examine other landing areas for concentrations of the same sort of thing, and send them to Mars on smaller follow-up rovers -- but NOT until after MSL has completed its more chemically sweeping search. Thus my flat vote against sending another MER-sized rover to Mars until after MSL (or even after two MSLs).

Good points. This does remind me that I've been wondering about MSL's RTG - as far as I can make out NH basically consumed all of the gloabally available Pu-238 GPHS fuel supplies as of the start of this year. Have the production issues now been sufficiently resolved to enable enough GPHS units to be manufactured for the required RTG? There's "plenty" of Plutonium around (a few hundred tons at least so) but how much of it is already suitably processed?

I'm also concerned about too much emphasis on simply chasing for life, which I seriously doubt is present now or has left any remotely measurable evidence if it ever was present. There are other things that we should be doing on Mars besides hunting for extant or recently extant life. Small static landers (not rovers) spread out over the planet to serve as Met stations, Seismometers, long term radiation\uv monitors, dust\tau sensors.. It's not headline grabbing stuff but very worthwhile if we're serious about going there. It's the sort of data that needs to be gathered for a (good) few years from a range of locations continuously in order to get the data that is needed in order to build accurate environmental models.

Do you realize what will happen if there are discoveries of "extant or recently extant life?" You'll get your wish list of devices. We won't need to poll about MER 3, we'll be talking about MERs 9, 10 & 11, and MSLs 4 & 5.

As one who holds both a science background and a marketing background, I can appreciate your argument, but even more so hope for the latter.

Much of the support for today's level of Mars exploration was boosted by the potential revealed in ALH 84001. We don't need to debate here the quality of those studies. As long as the imaginations of the media and the American public are titillated, support for the funding of Martian exploration will continue to grow.

"Titillated" is the right word. TV series often begin teasing the audience with something (usually a love affair) that might begin, but is frustrated for some reason or another. This keeps the audience's attention. If the affair is consumated, it becomes much less interesting (they could have made the series about a couple in the first place). Likewise, kidnappers lose all of their bargaining power if they kill the hostage.

If life is discovered on Mars, it may very well end the program of exploration after a short period to characterize that life, whereas the search for life (which could never end if there is, in fact, no life) could go on (some might say "drag on") forever.

A few years after putative martian bacteria/fossils were found, studied, and characterized, we might have a whole lot of analysis going on earthside, but the drama concerning locating anything on Mars will be very greatly reduced. There's a certain philosophical fascination with the possibility of life elsewhere (especially, a second biogenesis). It would be comparatively harder to take a search for martian life that had already been found in four places and passionately argue for a multibillion dollar program to see if it had spread to a fifth. Such opportunities abound in terrestrial biology, and excursions of that sort command budget outlays of something more like $100 to perhaps $100,000 (note this week's photography of a giant squid) -- not $10,000,000,000. When the "philosophical" significance is put to rest, so will all the extra digits in the budget. At that point, if it ever comes, we might remember that the US has only launched 2 missions to Venus since the 1960s ended.

While the discovery of Martian life might very well lead to an eventual deflation of the Mars budget, it would certainly still leave a stable Mars exploration program at a budget considerably higher than that for Venus exploration, or for the exploration of any part of the Solar System known to be lifeless. (And the latter figures are not exactly trivial themselves.) Biology will always attract more interest -- both from the general public, and from the science community itself -- than geology or meteorology does.

Moreover, it would take some time for the Mars budget to drop back even to that level in such a case. A much more likely negative event would be a worldwide panic over the prospect of bringing Mars samples back to Earth and unleashing (in the eyes of the public) a potential Andromeda Strain.

I have posted on this idea alot over on old google space,emailed steve before the launch on this idea as well.....................................I would build all new space craft but on the MER design . say 4 of them launch on delta but use ion power as the third stage and to make up for planetary alignment problems.maybe an earth flyby. but not sure what this does to mars atmospheric entry angles
so what if the citizens of california orderd up a bakers dozen?, MER design what would be the cost per unit? one space craft placed with each campus of the UC system JPL being a california organization would build the spacecraft. steve and folks like honeybee would have to move out here OR would have to bring gifts
IE bring the launch vehicle and the athena suite and NASA and out of state PI,s might get to tag along
Why do this? a dozen MER's could act as pathfinders much like the lunar rangers did. if just one of these MER's discoverd something "wonderful" then thats where you land the larger missions of 2009 and later.
california voters just passed the $ 3 billion stem cell project they might go for a $ 1 billion project. WHO is WITH ME?
mass production for MER launched over a decade 100 million per spacecraft.guests from other states invited if you bring gifts
Infocat13

Broadly, you have my sympathies - though I suspect that by seducing a couple of billionnaires to the cause we'd have entirely the same effect. Not that any well-heeled individuals are pursuing private space efforts...

There is a huge difference between spending hundreds of millions from the American Federal budget as opposed to spending the same amount from the California State Budget.

I'm as big a fan of space exploration as anyone here, but I for one, as a California taxpayer would lead the opposition to this wild idea if it were ever proposed.

Doug go ahead and pull this if you think we are getting too political here.

We dont have enough DSN dishes or relay capacity for a dozen MER's.

I agree - the design is amazing, it seems a shame to not re-use it, but MER has done it's job -and we now have a target to go and send more able rovers and landers.

Not going to pull anything yet - but yes - it IS getting too political

Doug

Part of the problem with the American approach to planetary exploration is the lack of continuity. The Mariners were the greatest examples of building upon a proven design, and they (Mariner 2 to be specific) were based on the Ranger design. The Voyagers were originally going to be called Mariners 11 & 12, and Galileo and Cassini are evolved from the Mariner class of spacecraft. But when it comes to Mars landers, each mission represents a whole new approach and that creates waste and higher mission costs.

MER is a phenomenal success, and there should be an effort to continue a similar class of missions specific and flexible lightweight rovers. Based on this winning design and complementing current programs, should have one per launch window. Of course, the launch vehicle will have to be upgraded from the Delta II due to the poor alignment trajectories for the next 10 years, but could you not place two spacecraft (a Scout and a MER) on say, an Atlas V?

The other deficiency in landers is the lack of weather station and seismometer. One way around that is to add a component to the lander. After the MER is deployed, a small solar powered weather station and seismometer could be deployed, along with other surface experiments vaguely resembling an ALSEP station. The MER, with a robotic arm, could assist with its deployment.

Imagine adding the Beagle 2 type components to the landing stage for the MER? It would be ultra lightweight and would finally give us a long term seismometer which still haven’t flown with the exception of Viking 1 (Viking 2’s never deployed properly) and Vikings, being inside the spacecraft rather than being deployed on the surface, was never a good platform.

The problem with a skycrane for the MSL is that it’s space junk once the mission was over. A soft landing stage would serve as a base for a small stationary experiment platform. I know that adding 30 - 50 pounds means compromising the rover, but you'd be gertting a lot of mileage out of those pounds.

It *does* seem to be poor economics to constantly build new-fangled toys then throw the designs away, like a Detroit car from the 1950s. Especially when you look at the way the Russians have managed their spaceflight enterprises for the last half century! However, despite it being an expensive-per-unit process, the US has consistently gotten a helluva data return for it's investment!

Perhaps we've not yet reached the position where the economies of scale can be relied upon to bounce Mars exploration along - but I think there's a place which *is* waiting for MER-style rovers (and in quantity).

It's the Moon. Think how readily the MER design could be made ready for exploring our neighbour (four wheels, isotopic heaters, a bigger antenna (to avoid the DSN burden)) and yes, you could have MERs being driven on behalf of dozens of agencies. Hey, you could *practice* all sorts of Mars tricks, too...

Bob Shaw

I wonder if an MER would overheat during a two-week-long lunar day, and if it would die during a two-week-long lunar night?

Doug

The ESA's current plans for ExoMars DO call for a Netlander-type package to be left behind at the rover's landing site, with later ones landed as opportunities arise (as piggybacks on other landers, or on their own -- maybe as Mars Scout proposals). However, if you run a network mission you want to make sure of having several such pckages working simultaneously; thus the need for a specific Mars network mission, which NASA now has set for 2020. (By the way, it was Viking 1's seismometer which refused to unlock -- thereby annoying me no end at the time -- and Viking 2's which worked perfectly for 2 years but in the end simply proved too vulnerable to wind gusts to produce any useful data.)

As for multiple MERs, you have to ask yourself just how much useful data they can turn out, given the small assortment of instruments they can carry in their present design -- especially given the need for Mars rovers to look for trace organics. IF such a capability can be built into a MER-sized rover -- and that's a very big "if" -- NASA may launch a pair of them as early as 2016.

However, Bob Shaw is quite correct that they have more potential application on the Moon (or on other bodies where only geologial studies are of interest) -- and in fact, during the first AO for Discovery proposals, Hawaii's Jeffrey Taylor proposed "Pele", a rover based on the abortive Russian "Marsokhod" that would have poked around the volcanic regions of Aristarchus with a MER-like instrument payload. Once again, though, you have to ask how much science you get for the buck with those, as compared with rovers that do such simple in-situ analyses and then actually collect periodic samples for later return to Earth and really detailed analysis. (The Mars sample return mission will carry just such a rover -- assuming that the entire SR lander doesn't drive around on the surface with the Mars Ascent Vehicle sitting on its back, which a recent study suggests would be comparable in cost.)

Yes and yes. Without some significant modifications to the thermal design key parts would either burn up if in direct sunlight and freeze out rapidly when in the extended lunar night. It shouldn't be hard to rework though.
At the same time a bit of re-engineering of the core systems to allow for 14 days of deep sleep would be needed but I'd expect that to be rolled up into the aforementioned thermal redesign.
For longer missions the lunar environment is a lot harsher - the lack of atmosphere would lead to faster degradation of the solar panels (radiation) but the improved insolation during daylight would mean you could get away with panels that were 50% smaller in the first place.
The proximity of the moon would make comms much simpler which should allow for a much cheaper ground support structure.

One very useful benefit of hacking such a rover together would be to just get a comparison on the overall wear and tear a successful martian design experiences on the moon.

EDL would have to be totally different obviously, but I think the 'chassis' design is good, however given that you would be doing something more like real time ops instead of daily uplinks, you would have to redesign the systems quite a bit, 'video' cameras not stills etc etc

Doug

VikingMars, the 1984 Viking III project You mentioned is in fact visible in my avatar on the left... It was supposed to be a regular Viking lander equiped with wheels

check this site: http://science.nasa.gov/newhome/headlines/msad28apr98_1b.htm

Click to view attachment

Viking 3 lander with Elastic Loop Mobility System. Too bad they didn't put this on Phoenix!