Sunday, August 1, 2010

Latest Decadal Survey Update

The following open letter from the Survey's chair, Steve Squyres, was published today.  You can read the original at

Dear Colleague:

This is the sixth newsletter to the community regarding SolarSystem2012, the planetary science decadal survey. The key points in this newsletter are these:
  1. The five decadal survey panels have completed their integration of the inputs from the community, and have provided their recommendations to the steering committee.
  2. Cost and technical evaluations for the highest priority missions recommended by the panels are nearing completion.
  3. Final prioritization of mission candidates and other activities by the steering committee is underway, and will be completed within the next few weeks.
  4. A report is being drafted, and we expect it to begin a comprehensive peer review process beginning in late September.
  5. We hope to have a final report ready to present to the community by next spring.
  6. More information is available on the SolarSystem2012 web site:

Late spring and early summer were an exceptionally busy time for the five panels, as they finished working through all of the inputs from the community, integrating them for inclusion in the final decadal survey report. The statistics on the community inputs were impressive, with 199 white papers written by 1691 unique authors and co-authors. The panels also worked closely over this period with the Applied Physics Laboratory, Goddard Space Flight Center, and the Jet Propulsion Laboratory to perform detailed studies of a large number of candidate missions that arose from the community inputs.

After receiving the mission studies from the panels, Aerospace Corporation, under contract to the NRC, has performed a number of detailed cost and technical evaluations of the candidate missions. Most of these evaluations are now done, and the final few will be completed within the next two weeks.

Once the steering committee has received all of the scientific inputs from the panels and all of the technical and cost evaluations from Aerospace, the final prioritization of mission candidates will take place. The challenge, of course, is finding the best solar system exploration program that fits the projected budget.  Much of the prioritization has already been done by the panels themselves, so the number of decisions that the steering group will have to make is small. As always, our decisions will be driven by our assessment of the community’s views on the science value and cost effectiveness of all the missions and other activities under consideration. The final prioritization will be completed within the next few weeks.

A report summarizing the current state of knowledge in planetary science, the key outstanding science questions, and the affordable mission candidates and other science activities that best address those questions is being drafted. Most of the report is now written, and we expect to have a final draft done within the next two months. Once that draft has been submitted to the NRC, it will undergo a long and rigorous peer review process, per NRC standards. Many of you in the community will be asked to review it; if you do get asked to provide a review, a timely response will be greatly appreciated!

As soon as the report has been through the review and revision process, it will be released publicly. We expect that the release date will be sometime in the early spring of 2011. After the report has been released, we will also be able to provide briefings about it to the community at major science conferences… so stay tuned for those.

I’d again like to thank everyone in the community for your many inputs to this process. The set of activities that we have studied is breathtaking in its scope, and finding the subset that best addresses your highest priorities while fitting into a limited budget is turning out to be both challenging and rewarding. I’m excited
about the recommended plan that is emerging, and I think you will be too.

As always, more details, including archived webcasts of meetings, agendas for past and future meetings, and materials presented to the Steering Group and panels, are available at the SolarSystem2012 web site:

Best wishes,
Steve Squyres
SolarSystem2012 Chair

Editorial Thoughts: The Survey is in the publicly quiet time where priorities are being set and justified.  We are unlikely to hear much about the missions selected until the release of the report next spring.

I suspect that the prioritization by the steering committee may not be as easy as suggested by this letter.  There are at least two or three Richter scale decisions: Should any of the flagship-scale missions (Mars sample return caching rover, MAX-C, Jupiter Europa Orbiter, Saturn-Titan-Enceladus orbiter) that likely will top at least some of the panel's priorities be funded and if so, how many?  Should substantial funds be committed to development of follow on elements of the Mars sample return to allow the fastest possible return of samples cached by MAX-C?  Should one or two destinations (or types of destinations, e.g., comets) be prioritized and receive substantial funding much like Mars was in the last decade?

The easiest solution would be to pick the top missions from each panel (Mars: likely Trace Gas Orbiter and ExoMars/MAX-C, Outer Planets: likely Jupiter Europa Orbiter, etc.) and fund them until the likely money is gone.  However, if any of the flagship-scale missions that may be the highest priority of a panel run into serious cost overruns, then paying for the cheaper lower cost missions may not be possible.  This happened with both the last astronomy (James Webb Space Telescope) and planetary (Mars Science Laboratory) surveys.  The technical and cost evaluations being done will help avoid this problem, but probably not eliminate the risk.

A recent report by the National Research Council showed that many missions experience their major overruns well into development when the designs are presumably well understood.  From the report:

  • "Past studies of cost growth in NASA Earth and space science missions calculated values for average cost growth ranging from 23 percent to 77 percent.
  • "Relatively little cost growth occurs between preliminary design review (PDR) and critical design review (CDR). 
  • "A majority of cost growth occurs after CDR, with the rest occurring prior to PDR.For one large set of 40 missions, 80 percent of the total cost growth (in absolute dollar terms) was caused by only 11 missions."

And, "So 75 percent of cost growth occurs after CDR. Primary Reference 5 also analyzed the evolution of cost growth over time and concluded that “it is important to notice that, unlike the mass and power growth time trends, cost growth is typically not recognized until after CDR."  (PDR is the preliminary design review that occurs early in the project while the CDR is the critical design review that occurs later before committing to development.)  Cost overruns on larger missions often are more damaging than overruns on small missions (25% of $3B is much more in absolute dollars than 25% of $650M).

At the same time, I personally would not like to see a list of missions that are all safe because the technologies are firmly developed.  If I were to wager a beer, my guess is that the Survey will prioritize only one flagship scale mission and fill out the rest of the program with smaller New Frontier and Discovery class missions.  But I wouldn't bet more than a beer on this prediction.

I look forward to seeing how the Survey balances these conflicting priorities.


  1. You stated

    "The technical and cost evaluations being done will help avoid this problem, but probably not eliminate the risk."

    I would certainly agree with the risk statement. My greatest concern is that the independent cost evaluation performed by Aerospace Corporation might be wildly inaccurate, particularly for some of the larger scale projects.

    In my opinion, having a single contractor perform the cost evaluation process is dangerous and perhaps even foolhardy given the complexities involved.

    I would be much less concerned if two or even three independent contractors were used in the process. If all contractors converged on the same solution, it would lend much greater credence to the cost figures. Significant cost deviations between contractors for a particular project might signal a serious problem with the project scope, definition, or understanding thereof. In any case, the proper action would then be to reconcile the differences thereby providing (hopefully) a more accurate final result.

  2. I noticed your list of potential flagships didn't include a Mars geophysical network mission, which I've been hoping for. Does that mean you think it's out already?

  3. I have no idea if the network is in or out. Technically, I think it would count as a small flagship as I've heard costs of ~$1.5B. I was only addressing large flagships in the post. (Another perennially favorite small flagship is a cryogenic comet sample return.)

    The network mission has always seemed to suffer from following really large Mars missions on priority lists. I think that if it were to stand on its own against similarly priced solar system missions it would do quite well. That seemed to be the reason to add it to the list of possible New Frontiers missions. However, by the time the big Mars missions are funded, the decision always seems to be to spend remaining funds on other solar system targets since the Mars program already has received its share.

    This mission is a favorite of mine, too.

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