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Posted by: pioneer Jan 20 2005, 07:28 PM

I realize MSL has more neat features and will last longer, but the design on MER has been proven to work since Spirit has lasted over a year and Opportunity is close behind. MER is cheaper than MSL because it will use solar power and won't take as much testing since it is using proven technologies. What I'm wondering is why not re-use a design that works?

Posted by: djellison Jan 20 2005, 09:03 PM

Because it doesnt have the payload accomodation to do the bio-science required, or the data handling capactity for the HUGE data products suggested for the MSL payload.

Doug

Posted by: centsworth_II Jan 21 2005, 12:33 PM

I certainly don't suggest replacing MSL with multiple MERs, but it would be great to have multiple MERs sent to Mars in addition to the MSL. They may not do bio-science, but there is still a lot of "geology" left to do on Mars.

Posted by: djellison Jan 21 2005, 12:43 PM

Well - if the question is why not send more MER's - the answer is money

Doug

Posted by: YesRushGen Jan 21 2005, 02:31 PM

I've brought up this suggestion a couple times here, Pioneer. It would be really great to augment the ongoing Mars Exploration with more MER pairs on each launch opportunity. Like Doug says, the main reason for not doing so is money.

However, my counter to that is that the cost of the MERs would drop with each production run of them. If some company picked up the design, they could probably find ways to reduce the cost.

Just think of the potential of a generalized MER design, where you could literally plug-n-play the instrumentation.

Further, I realize that the science performed by MER will not hold a torch, much less a candle, to the since done by MSL. However, I think MER is sufficient to at least survey many different locales on Mars.

Perhaps they could even "get jiggy with it" and land in some more difficult places. MER's EDL has proven itself. Based on the two landings to date - how the atmosphere behaved, etc, they could pin down the landing ellipse I think.

Too bad there's no way for us to make this idea known. NASA/JPL is probably so focused on MRO, Pheonix and MSL that the thought of future MERs may not have even occured to them.

Posted by: djellison Jan 21 2005, 02:55 PM

Maybe someone will propose a single MER for the next mars scout ( ermm 2011 I think ) based on MRO data

Doug

Posted by: tedstryk Jan 21 2005, 03:17 PM

I think part of the problem is not only instrumentation limits, but instrumentation that can tolorate the relatively hard landing of the MERs. One good question is whether or not there are enough MER leftovers (a la Marie Curie from Sojourner) to build another rover. If such a rover or the pieces to build one exist, I would propose sending it somewhere very different (Tharsis maybe?) and/or with different instrumentation.

Posted by: djellison Jan 21 2005, 04:03 PM

I thikn the altitude at tharsis would preclude a landing using MER EDL there - but certainly places like Vallis Marineris, Isydis Planatia etc

Doug

Posted by: YesRushGen Jan 21 2005, 07:37 PM

Excluding the cost of building the rover, how much does the Delta II cost to launch it to Mars?

Couldn't some sort of business model be constructed whereby a company would build (remember, each one built is cheaper than the prior one - mass production) and launch MERs, and then we the amateur community and/or the scientists could "subscribe to" (ie, pay for) the results?

Posted by: tedstryk Jan 21 2005, 08:43 PM

Still too expensive. It would be very difficult to, through subscriptions of scientists and individuals, raise that kind of money, even for a very cheap mission. And even if you were able to eek by, once failure and you would be totally sunk. I don't see the price of an MER dropping much below 300 million.

Posted by: djellison Jan 21 2005, 08:54 PM

How would such a paradigm shift occur? Currently PI's get paid to deliver instrumentation for mission - where would they get the money to PAY to fly instruments?

Doug

Posted by: lyford Jan 22 2005, 01:55 AM

http://start1.jpl.nasa.gov/caseStudies/mer.cfm has a good explanation of the limits of where MER could go... not the widest range of landing targets!

Posted by: BruceMoomaw Jan 22 2005, 02:34 AM

Let me assure you that there was a good deal of serious discussion of this subject at NASA's Mars Strategic Roadmap meeting two weeks ago . Unfortunately, I can't tell you what was actually decided yet, because that's part of my Coming Exclusive. (Bwah-ha-ha.)

Posted by: lyford Jan 22 2005, 04:38 AM

hmmm - now that is interesting....

i wonder...now that Pete Theisinger has moved on to MSL, does that mean they may now throw a few at Melas Chasma?

Posted by: YesRushGen Jan 23 2005, 04:20 PM

Yes, it is! It is very interesting. I'll bet that the centerpiece to the argument for sending more MERs is the fact that each one built will cost less than the previous. Think about it: A good chuck of the $800million that went into MER were research, development and testing.

Well, all of that is done. All that's needed is to crank up a factory floor, plop those babies on some Delta-II rockets and light the candle.

Yes, still expensive - but not as expensive as the Spirit/Oppy pair.

I stand by my guns. Launch two on every Earth->Mars launch window. The way Spirit and Oppy are going like the energizer bunny, this could lead to continual rover presence on the red planet!

Posted by: BruceMoomaw Jan 23 2005, 10:26 PM

A warning: you guys are jumping to very premature conclusions about what the Committee decided (although you may find what they DID decide a consolation prize). That's all I'm saying for now.

Posted by: djellison Jan 23 2005, 11:15 PM

There's lots of options I guess.....

One, two, or no MSL's in the '09 Opportunity

MER copies flown instead of or complimentary to MSL in '09

One or more MER copies flown in the '11 timeframe

Scrap the whole lot and launch an MSL derivative based on the bruce-crane that uses steel girders to drop a rover onto the surface in '13

Doug

Posted by: YesRushGen Jan 23 2005, 11:25 PM

I remember a recent article that said they were considering doubling up on the MSL rovers. I really hope this is done, considering the brand new EDL sequence.

However, I truely hope the committee has not decided to completely abandon the MER design.

Bruce, when will we know the "inside scoop" on this?

Posted by: BruceMoomaw Jan 24 2005, 01:48 AM

Very soon now. I've already finished a 21 1/2-page article on the Roadmap Committee meeting for Simon; but I'm also trying to sell a greatly shortened version to "Astronomy" or "Sky & Tel" (whichever one will pay me more; Astronomy has already agreed to buy it), and I haven't quite finished that one yet -- or heard back from Sky & Tel yet. Hopefully both those things will happen by tomorrow, and then I'll immediately send off the shortened version (which would appear on Astronomy's webpage, if they buy it), and then send off the longer version to Simon to be published shortly afterward (which Astronomy, at least, has agreed to let me do).