Kennel: Decadal Surveys Still Important Despite Challenges

Charles Kennel, chair of the National Research Council’s (NRC’s) Space Studies Board (SSB), believes that Decadal Surveys are still valuable strategy tools for the space and earth sciences communities despite the challenges of developing and implementing the most recent set.   Kennel’s views are summarized in a new report from the SSB on lessons learned from the Decadal Survey process.

The NRC conducts Decadal Surveys approximately every 10 years laying out priorities for several scientific disciplines for the next 10 years — hence the term “decadal.”   The SSB has led or co-led five Decadal Surveys published over the past several years:  Earth science and applications from space (2007), astronomy and astrophysics (2011), planetary exploration (2011), life and physical sciences in space (2011), and heliophysics (2012). 

NASA’s Science Mission Directorate (SMD) was the sponsor or co-sponsor of all those studies except life and physical sciences in space (which was sponsored by NASA’s former Exploration Systems Mission Directorate).  The four SMD studies were the subject of an SSB workshop last year assessing what improvements might be made when the next set of surveys is prepared.   A summary of the workshop was published today.   

NRC workshop summaries do not contain findings or recommendations, but this recounting of the 2-day workshop is rich with views of the scientists who were members of the Decadal Survey committees, NASA officials, and members of the international earth and space science communities.   Kennel’s concluding remarks lay out the highlights that he heard, or, as he says, did not hear.  Chief among them was that “Nobody said we shouldn’t have another decadal survey.”  

That being said, Kennel identified several key points that could be useful for future surveys.  Kennel’s observations as summarized in the report include the following:

• Decadal Surveys necessarily take the length of time they do (about two years), but should not “be made complex or elaborate than it already is”;
• the Statement of Task (SoT) for each study must be carefully negotiated between the NRC and the sponsor because the SoT defines the nature and scope of the study — Kennel paraphrased Steven Squyres, chair of the planetary science Decadal Survey, as saying “It’s the Statement of Task, stupid”;
• more international and interagency collaboration before a Decadal Survey begins would be helpful, and while that is an area where NASA must lead, the NRC could encourage NASA to “bring about an enhanced level of collaboration”;
• the language used to describe missions recommended in Decadal Surveys must be chosen carefully to accurately convey the level of detail (or lack thereof) that was available at the time the study took place and assessed by the survey committees using the Cost and Technical Evaluation (CATE) process;
• the CATE process itself must be carefully described “because the CATE estimates are so probabilistic …. that including a description of the uncertainty in cost would better illustrate that the CATE numbers are notional at best, thus conveying cost and risk at the same time”;
• future surveys could “explicitly assign a risk acceptance level” to the recommended missions especially since large missions may demand a higher risk management commitment than smaller missions.

The NRC has published Decadal Surveys in astronomy and astrophysics since 1964.   Surveys for the other space and earth science disciplines began early in this century.  Historically, they are referred to as “bibles” for NASA’s science program since they represent a consensus of the top experts in each of the scientific disciplines and NASA endeavors to execute the missions prioritized in the surveys.   At the beginning of each study, NASA provides an estimate of how much money will be available for new missions during the decade under study. The NRC survey committee sets its priorities based on scientific value and estimated mission cost and risk. 

For this recent round of surveys, however, the actual amount of money available to implement recommended missions is much less than NASA — and therefore the survey committees — expected.  The discrepancy is due either to cost overruns on existing programs that leaves less for new starts or to overall constraints on NASA’s budget.  Thus, the top priority missions recommended in several of the surveys cannot, in fact, be implemented in the near future, leading many in the space and earth science communities exasperated.    Individuals who serve on NRC committees are not compensated, yet they must take time away from their research and personal lives to volunteer for these intense efforts and some question whether it is worthwhile.  In Kennel’s view, the answer clearly is yes.