The National Academies has released a report on the senior reviews that NASA conducts to recommend extensions of its science missions beyond their planned end dates. The report praises NASA’s management of its extended-mission portfolio and offers recommendations for augmenting the review process.
Last week, the National Academies of Sciences, Engineering, and Medicine released a report entitled “Extending Science—NASA’s Space Science Mission Extensions and the Senior Review Process.” NASA requested the report last year to assess the process that its Science Mission Directorate (SMD) uses to determine whether and how its missions should continue beyond their prescribed end dates. To study the issue, the National Academies convened a 13-member committee, co-chaired by Victoria Hamilton, a planetary geologist at the Southwest Research Institute, and Harvey Tananbaum, an astrophysicist at the Smithsonian Astrophysical Observatory and former director of the Chandra X-Ray Center.
The committee notes that, of the approximately 60 NASA science missions currently in progress, about 45 have entered their extended phase. The exact number of missions is open to interpretation because some missions incorporate multiple spacecraft and can be partially extended. The committee affirms that mission extensions often provide highly valuable scientific observations while collectively consuming only about 12 percent of the SMD’s annual budget. The committee rates NASA’s present balance between new and extended missions as “excellent,” and reports “a strong consensus” among its members “that NASA’s approach to extended missions is fundamentally sound and merits continued support.”
Committee recommends clarity in mission-extension policies
In line with its favorable view of NASA’s approach to mission extensions, the committee recommends that the agency more formally incorporate anticipated extensions into its policies. In particular, the agency “should include advance planning and sufficient funding to optimize the scientific return from continued operation of [extended-phase] missions.” After a mission’s first two senior reviews, the committee recommends providing constant, inflation-adjusted funding for “high-performing missions.” Additionally, if a review concludes there is insufficient funding to continue a scientifically promising mission, rather than terminate the mission NASA should “allow the [mission] team to re-propose with an innovative, possibly less scientifically ambitious, approach at reduced operational cost and increased risk.”
In general, given NASA’s success with extended missions, the committee recommends that the agency make information more readily available about its experiences with them so as to inform planning for both the prime and extended-mission phases of future missions.
Best practices suggested for review process, panel composition
While strongly approving of the SMD’s review process, the committee does find some room for improvement. Most notably, it recommends that NASA conduct senior mission reviews every three years rather than every two, citing the “excessive burden” that the reviews currently place on the agency, its mission teams, and the senior review panels themselves. Because Congress enshrined biennial mission reviews within NASA’s authorizing legislation in 2005, the committee recommends that NASA ask Congress to revise that provision.
The committee also suggests a variety of adjustments to the mechanics of the senior review process. Among these, it recommends that NASA increase the flexibility of its review schedule to accommodate the particular technical and scientific circumstances that shape mission schedules. It also suggests that the SMD as a whole take a page from its Earth Sciences Division, which conducts annual technical reviews to assess the health of its spacecraft and their instruments. While the committee reports that other divisions have accepted that mission extensions are inherently risky, it believes that a “moderate” assessment of technical risks should nevertheless balance panels’ assessment of anticipated scientific gains. The committee also suggests that continuity of measurements be considered as much as the likelihood of “new science” as a criterion in favor of mission extension.
Concerning the composition of senior review panels, the committee suggests that most members be senior scientists with knowledge of the mission’s operations to ensure the “operational context” is taken into account. However, it also proposes inclusion of “some early-career members to introduce new and important perspectives and enable them to gain experience for future Senior Reviews.” The committee stresses the value of continuity of panel membership on reviews of particular missions “to take advantage of corporate memory.” It also recommends that panels be “assembled early to avoid or accommodate conflicts of interest and ensure availability of appropriate expertise.”