Post MSL Roadmap Options

[vjkane]

Several of the presentations from the past MPEG meeting were posted recently

http://mepag.jpl.nasa.gov/reports/index.html

These include Draft priorities for Mars Sample Return, Mars Science Orbiter (MSO) Science Definition (nothing new, but a nice summary), and the Mars Strategic Science Assessment Group.

I found the latter document extremely interesting. It defines the rational for MSO as the mission to follow Scout 2013. It also defined 8 distinctive classes of deposits (of which Opportunity is exploring one) with emphasis that six have been identified in just the last three years showing that "we are still in an active phase of discovery". Understanding these deposits "are critical to understanding the history of water near Mars' surface." Ideally, it would seem to me, MSL and ExoMars would each explore a different type.

Most interesting for me, was the rational for a twenty year roadmap of exploration based on the assumption that sample return #1 begins at the end of the next decade:

2013: Mars Scout aeronomy
2016: MSO - determine presence and source of key trace gases, continue detailed monitoring of climate, continue to characterize surface with Hi-Rise class camera (and not mentioned, be available as a communications relay)
2018: MSR - lander/rover
2020: MSR - orbiter
2022: Mars network. Not chosen for 2016 in part to allow lessons learned from ExoMars geophysical station to be incorporated
2024: Mid-range rover (MER sized, but with updated instruments and tighter landing ellipse) - explore new class of deposit
2026: Scout
2028: MRS #2 orbiter
2030: MSR #2 lander/rover

Speculation: if budgets don't allow for a sample return in the 2018/20 opportunity, I wonder if the sequence of other missions would simply move forward, and perhaps a second mid-range rover would be added. Also, could these mid-range rover be powered by Sterling-engine plutonium systems?

[PhilHorzempa]

If we are to delay Mars Sample Return, then I would like to see a few more mid-size rovers
sent to check out deposits at any one of the 20 unique geologic units on Mars. Also, whenever
MSR does get a definite go-ahead, I would like to see it put up for competitive bid, by way
of a Flagship AO. I think that we should stop assuming that JPL is the only place where Mars
rovers or the MSR can be built. Phoenix was built by Lockheed-Martin, as well as Mars Odyssey.
An AO for the MSR mission would allow other capable parties, such as APL, to propose
a design. Recall that Viking, the mega-Flagship project in Mars exploration, was led by
NASA-Langley, with the Orbiter built at JPL and the Lander built by Martin Marietta.

Another Phil

[gpurcell]

I agree with all of that, Phil. In fact, I think we'll end up seeing MSR restricted to locations where we have established ground truth and know we'll get rocks that are worth the huge cost.

[vjkane]

I also agree that we should delay MSR until we have several more landers down. You want to know that you are sampling the *one* best spot.

Phil, I like your idea of competition, but I worry that enabling MSR may take a decade of technology development. Whoever does the technology development will have an edge that will be hard to match outside. I'd like to hope that I'm wrong...

[imipak]

I worry that enabling MSR may take a decade of technology development.

I think a decade is over-optimistic for MSR. Here we are in 2008 with a grand total of one successful rover mission to date. (OK, two vehicles, but one design.) Assuming Phoenix and MSL are roaring successes, I can conceive of a bigger more powerful rover design, better targeted with the benefit of another decade or so of HiRISE class and other advanced remote sensing, that's capable of collecting multiple samples and returning them to a central site being feasible in ten years. I can just about imagine a Mars orbiter with enough fuel capacity, and reliable enough engines, to get itself back to Earth from Mars orbit becoming feasible in 10 to 15 years' time. But I suspect getting the samples off the surface and accelerated to 5 km/s (compared with the moon at 2.4 km/s) [source - wikipedia] will take a lot more trial and error.

I know there are design concepts, I just think a remote or autonomously controlled take-off from Mars to orbit, by a vehicle that will already have had to get there from here is going to take a lot of blood sweat and tears and probably some failed attempts along the way. Flight ready hardware within a decade just looks like too big a stretch to me, even on $650m / yr.

Too pessimistic? I hope so.

[vjkane]

For the really big missions -- Mars sample return, Europa orbiter, Titan missions, Venus long lived surface missions -- there is a lot of technology development that needs to be done. I personally think that Titan is more interesting than Europa, but the next Flagship mission is likely to go to Europa because NASA has invested well over a decade in the technology development and mission definition. That's why the recent assessment of Flagship concepts rated both sites as excellent for science, but Europa medium risk and Titan high risk.

JWST and MSL's cost overruns are likely, in my opinion, to be due to the problems of having to develop technologies as part of the mission development. (Caveat: I don't follow the implementation problems of either closely enough to know this is true.) You can get around this problem by vastly over resourcing the development. My former employer, which had development programs that were a meaningful fraction of a Flagship mission, did this for some projects. It worked, but it was expensive.

I like the idea of open competition for mission ideas and implementations that is done in the Discovery and New Frontiers lines. However, these missions can draw only on the technology that is already developed. (Fortunately, there's a lot of interesting places to go to with developed technology.)

The planetary community needs to decide the order of Flagship missions about 10 years before their formal mission New Starts. That gives NASA the lead time to work through the development ahead of time.

[vjkane]

Space News just posted an article about MSL's cost overruns. The best defense against these problems is to thoroughly define and partially predesign missions up front so that these problems get worked out before full development begins. You can still be surprised, but the number and costs of surprises goes down.

Perhaps what NASA needs to do is to add a formal Flagship project line to its budget to fly one every 7-10 years. The budget line would include any mission, Mars or otherwise, that exceeds $1B. About 5 years before the time for a new start, NASA could have a competition of concepts, much as it has just done for the next Flagship mission, and select the two best for 5 years of predefinition and technology development work. Then when it comes time to select the new start, NASA has two well defined missions to chose from.

Here is a portion of the article regarding the source of MSL's cost overruns (http://www.space.com/spacenews/spacenews_summary.html):

"During a March 12 presentation at the Lunar and Planetary Science Conference held in Houston, Stern said the MSL's total cost has grown to about $2 billion.

"MSL tried to put too much in the bag from the beginning," Stern said, recalling to the audience that it begn as a $750 million mission. "We were kidding ourselves as a community and as an agency that you could do that."

"We need to do this" mission, Stern said, "so we need to come up with the money."

Stern said no single aspect of the MSL undertaking is to blame for the overrun. "It's rife through the whole project," he said, adding that NASA and its contractors underestimated the scope of the task.

[Mark6]

What launch vehicle is MSL going to use?

[mchan]

Atlas-V 541

[mcaplinger]

Space News just posted an article about MSL's cost overruns. The best defense against these problems is to thoroughly define and partially predesign missions up front so that these problems get worked out before full development begins. You can still be surprised, but the number and costs of surprises goes down.

Alas, the cited article is nearly content-free about the actual problems MSL had. Your "best defense" above; I don't disagree, but how do you pay for "predesigning" a mission? You're just moving the cost from one column to another, you may not save anything.

The best defense against overruns is to relax the requirements/descope as the cost ceiling is approached. If you don't do this, you better make sure you can cover the costs, because you can't have it both ways.

[vjkane]

Your "best defense" above; I don't disagree, but how do you pay for "predesigning" a mission? You're just moving the cost from one column to another, you may not save anything.

I disagree. Five years -- a typical time from new start to launch -- is a very short period for doing a design, developing technology, and resolving problems. It is essentially a crunch time in which your options are to descope or throw money.

I worked in the high tech industry for years. My company spent extensively on technology development so that when a product (our equivalent of a mission) wanted to use the new technology it had already gone through its problems. The most successful programs were those where the new technologies and combinations of new technologies were extensively prototyped before hand. You always want to find out where the problems will be as early as possible so that you can address them in as a normal part of design and not as a crisis.

It was always obvious which programs would run into trouble. They were the ones that either (1) incorporated new techniques without either gobs of resources (2-3X normal staffing) or extensive predesign and prototyping, and/or (2) were approved on optimistic schedule and/or budget projections (we always knew which those were, but management, it seems, too often believes in Santa Claus). It never failed.

All serious design challenges have to resolve lots of problems. You just want to uncover them as early as possible. If you want to fly to Europa -- very challenging mission because of the radiation -- begin your technology development and design work 5 years before the new start. Resolving problems before its a crisis is almost always cheaper, and it leads to fewer problems discovered when your deep into design, cutting metal, and testing and there's a launch date just a couple of years away. I think NASA needs to put serious funding now into design and technology development for both MSR and a Titan mission. The Europa mission has had a decade plus of technology development and mission design, and it showed in the maturity of the Flagship proposal and the medium risk rating it received (compared to the Titan mission's high risk rating). You are right, you may not save money in the long run with all the up front work. You can budget that upfront work, though, and not have to rob other programs because it has become a crisis.

[monitorlizard]

mepag.jpl.nasa.gov/meeting/mar-09/index.html

There is a wealth of interesting presentations from the MEPAG meeting early this month at the above website. Some of the highlights I found:

--MELOS, an ambitious Japanese orbiter/lander Mars mission, set for 2016-2020
--still talking about a possible U.S. science orbiter for 2016, descoped for the tight budget situation, but with increased interest because of detailed methane studies that could be conducted
--an ExoMars presentation with some cool graphics
--current thinking seems to be for 2016 ExoMars to be European-led with significant U.S. contributions, and a 2018 rover that is U.S.-led with significant European contributions
--Mars Sample Return is out of the question in the current budget climate

[Vultur]

I think a decade is over-optimistic for MSR. Here we are in 2008 with a grand total of one successful rover mission to date. (OK, two vehicles, but one design.)

Why is Sojourner not considered a successful mission?

[dvandorn]

I have a hard time defining MPF as a "rover mission." It was basically a technology demonstrator for the airbag landing technique, with a rover technology demonstrator.

Sojourner's science package was, to be honest, next to useless. Its cameras returned poor images with poor resolution, and its APXS took some great measurements of the dust on the outsides of some rocks (without a RAT or any other way of removing dust from the rocks, it never got a really decent look at the composition of the rocks themselves). The best science of the mission, IMHO, was done by the Imager for Mars Pathfinder (IMP) camera on the lander.

Not that MPF was a failure -- it just wasn't really a mission designed to land a rover and then do science with the rover. It was a mission to validate the airbag technique and to pioneer wheeled-vehicle operation at a Mars-to-Earth remove. It was an engineering mission, with a few science instruments added on to take advantage of anticipated engineering successes.

In purpose, it was rather like Surveyor I, which had all scientific instruments stripped off so it could serve as an engineering test. The only "science" payload on Surveyor I was its TV camera, which was used as much for engineering analysis of the Surveyor itself as it was for scientific analysis of the lunar surface. And looking at it, the only real science payload on MPF consisted of the IMP camera, the meteorology boom, and the APXS on the rover. The (rather deficient) wide-angle navigation cameras on the rover were designed solely for engineering/operational purposes; rather as with the MERs, these hazcam-like imagers weren't designed to do science, they were designed to help the operators drive the rover.

So, it's not like MPF and Sojourner were failures, it's just that it wasn't what I would call a "rover mission." The Mars 2001 lander wouldn't really have been a "rover mission," either, IMHO, even though it was scheduled to carry Sojourner's sister-toaster, er, rover, Marie Curie. It would have done more of its science from the lander than from the mini-rover, and once again would have been more like an engineering demonstration than a full-fledged rover ops mission.

-the other Doug

[tedstryk]

Sojourner, while limited, certainly wasn't useless. The APXS results gave a clear indication of water in the past, as evidenced primarily by excess oxygen in the rocks from water bound up in them. The problem is that due to calibration issues and the problems caused by the lack of a brush to clean the rocks off, these results did not come out until late 2003, so they were quickly eclipsed by Oppy at Eagle Crater. Had there been a longer gap between missions, this result would have gotten more fanfare. Still, it did serve more like a really long robotic arm than a rover.

http://adsabs.harvard.edu/abs/2003JGRE..108.8096F
http://adsabs.harvard.edu/abs/2003AGUFM.P12C..06F