Sunday, March 6, 2011

A Decadal Survey Preview?

Decadal Survey reports are kept confidential until their release.  Space News provides a purported preview of the report based on a draft summary it obtained.  We'll have to wait until Monday to find out if the summary represents the final report.

The article reports that the Survey's three recommended Flagship missions in order of priority would be:

  • The Mars MAX-C/ExoMars dual rover mission with a price estimate of $3.5B [Editorial note: This would be over $1B higher than other estimates that I've seen].  The report purportedly recommends that the mission be approved only if it can be flown for $2.5B.
  • The Jupiter Europa Orbiter is estimated at $4.7B [Editorial note: This would be approximately $1.5B more than previous estimates that I've seen].  The report apparently will recommend it be flown only if the cost can be reduced and NASA's planetary budget increased.
  • A Uranus orbiter and atmospheric probe at $2.7B, which is recommended for approval in the coming decade at this cost

The article states that the Survey based its recommendations on the FY11 budget forecasts.  The new FY12 budget forecasts would substantially reduced that funding outlook.  The article has two quotes that suggest that the FY12 forecasts will be the ones that NASA uses.

Reportedly, the Survey will recommend selecting two New Frontiers-class missions from the following list: A Venus in-situ explorer, lunar South Pole-Aitken Basin sample return, lunar geophysical network, comet sample return, an Io mission, a Jovian Trojan asteroid mission, and a Saturn atmospheric probe.  It's not clear from the article whether or not these two missions would include the New Frontiers mission selection currently underway or would be two additional missions.

The Decadal Survey will also recommend continuing with new Discovery missions.

Editorial Thoughts: This article leaves me in sticker shock.  If the Flagship mission cost estimates are correct, they are substantially higher than previously reported.  And if the FY12 budget forecasts are the ones that NASA will use to respond to the Survey's recommendations, then I don't see how either the Mars or Jupiter-Europa missions as defined can be fit into a reduced budget that includes Discovery and New Frontiers missions.  Funding the Uranus orbiter and probe mission may be difficult.

If the sticker shock is as bad as the article suggests, I would expect that attempts may be made to redefine the two big flagship missions to fit within a budget NASA could afford.  If that fails, the Uranus mission plus the New Frontiers and Discovery missions may be the program for the coming decade.   Another alternative might be for the Survey to reconvene to reconsider its recommendations in light of a tighter budget.   The mission concept studies included several smaller flagship missions that were less expensive than the Uranus orbiter and probe concept.  (However, the cost for the Uranus mission quoted in the article is approximately $800M higher than the one quoted in the mission concept study; other smaller Flagship missions may also suffer cost increases with greater examination.)

The article does not discuss the status of the joint ESA-NASA 2016 Mars Trace Gas Orbiter mission.  It also does not discuss whether the 2018 ESA ExoMars rover mission could be afforded by ESA without NASA participation.  ESA had decided to enter a joint program because it needed the additional funding from NASA's participation.

I'm personally disappointed that no mission to Titan or Enceladus reportedly are included.  I'll be interested to see if the report gives reasons why neither moon was a priority.  If there is no Mars mission in the coming decade, that will be another disappointment for me.  I had also hoped for a new mission to Neptune's moon Triton in my lifetime, but that now seems unlikely.


  1. If the Pu-238 issue isn't resolved soon, Jupiter Europa Orbiter & Uranus Orbiter w/Probe may be moot anyway.

    While I'm not terribly fond of the idea of another decade of focus on Mars, some program is better than no program. Just getting the 2 New Frontiers and 4 Discovery would be better than nothing.


    G Clark

  2. As I recall, the Uranus orbiter would not require that much plutonium. I've never seen a good accounting of how much Pu 238 is stockpiled, but my guess is there's enough for the Uranus mission plus 1-3 Discovery or New Frontiers class missions.

    As for Mars, NASA's current plans are built around the MAX-C rover. If that is not funded, I'm not sure if another Mars mission will be substituted.

  3. 1) If they want to reduce the budget on the Mars dual-rover mission, it seems like it's not "rocket science" that one way to do that is to make it a single-rover mission. Of course, that would depend upon the ESA support not disappearing should such a cut be made.

    2) Generally speaking, since there more sites of high interest for sampling the early phyllosilicate layers on Mars than there are planned missions preceding a putative sample return, it seems like one way to retool the program would be to plan cheaper reconnaissance landings in those sites and try to focus the MSR goals with the cheaper recon. Note that two MERs cost $820 million. If $3 billion per rover is a dead end, the path to MSR may involve more rovers, each of which is less capable than MAX-C but more (or different) than a MER. Even a Netlander program might serendipitously help us rule a proposed site in or out for MSR.

    3) Uranus seems almost like a "poison pill" candidate meant to shock the system into favoring some other candidate. Relative to most other destinations, Uranus has only one thing in its favor: It has only been seen with one previous flyby. Relative to Neptune, it has proximity in its favor, but lacks a Triton. The uranian system is rather like that of Saturn if you subtracted the three most interesting moons, and it is apparently the only giant planet that doesn't have at least one volcanic moon. I love Uranus for its own sake, but in comparison to the other potential targets it cannot possibly win out.

    4) One planned capability of JEO was radar that could probe the icy shell rather deeply. Much of the community believes that the ice is roughly 19 km thick. However, Richard Greenberg argues -- on the basis of surface morphology -- that the crust is much thinner; e.g. 6 km. If the crust actually is thin, then radar that can peer deeper into water is apparently a waste of instrumentation. It seems to me that the debate about crustal thickness has much to do with possible descoping. For example, if radar could peer only 10 km deep, then it could settle the thin/thick question... telling us all we needed to know IF the answer is "thin." Failing to find the bottom if the crust is thick, but placing a lower bound on the thickness, which is perhaps knowledge enough to plan whatever next mission might follow. Moreover, a mission with NO radar but excellent imaging and altimetry might provide compelling evidence to settle the thin/thick debate, which is currently severely constrained by the paltry coverage afforded by Voyager+Galileo. Superb data on crater morphology for all impact craters would all by itself be a significant upgrade on current data. A radar-less mission might meet the current budget goals and pave the way for a subsequent orbiter with radar or even to skip the radar for a landed mission.

    Overall, I think the priorities need to be to keep Mars and Europa as the top two targets of interest but with more incremental approaches to keep per-mission costs way down; we should keep those priorities, and resign ourselves to an architecture that gets to the big questions over a longer span of time.