An overarching cross-mission science and applications coordination effort would help ensure that programmatic decisions on potential delays or augmentations/reductions in the capabilities of a particular mission would be evaluated in light of the overall mission set and integrated requirements rather than as “one off” decisions.3 The science and applications coordination effort should include appropriate interaction with the already-established system engineering working group4 and mission system engineering teams to stay apprised of cross-mission areas of mutual interest5 and should be conducted in an ongoing manner as science requirements and mission designs and costs evolve—with the participation of other agencies and international partners/stakeholders when appropriate.
As discussed in Chapter 3, the 2007 decadal survey report put forth mission concept descriptions and notional costs that were intended mainly to set targets for each mission that are consistent with an overall program that is affordable while denoting the relative cost of one mission with respect to another, which factored into mission priority and phasing.6 After release of the survey, teams were formed by NASA to further develop each of the recommended mission concepts. Based on discussions with the director of the Earth Science Division (ESD) and individual mission team members, the committee learned that teams operated primarily in a “requirements-gathering” mode, unconstrained by even notional cost targets.7 Unfortunately, this approach created an atmosphere in which science requirements and scope tended to grow, as did cost estimates.8 Furthermore, there was apparently insufficient consideration given to the effect of individual mission cost growth on the entire queue of recommended missions.
3 This cross-mission science and applications coordination effort could, for example, encourage studies and trades across missions where synergies anticipated in the survey report might not be readily realized in the mission concepts as presented, or within available resources. Indeed, the need for further optimization was recognized by the survey authors, who stated, “The selected missions reflect the panels’ prioritization of scientific observations but are not the result of an exhaustive examination of the trade-offs across the entire range of potential missions. Clearly, more detailed cost estimates are needed that examine the full range of mission tradeoffs….” (National Research Council, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, 2007, p. 43.)
4 The Earth Systematic Missions Program Office has established a systems engineering working group with representatives from each center.
5 Science stakeholder participation in the A-Train Constellation Mission Operations Working Group is an example of such effective interaction.
6 The decadal survey cost estimation process and purpose are described further in Box 2.3 in the 2007 report: “Nevertheless, the estimates provided in this study set targets for each mission that are consistent with an overall program that is also affordable. The panels recognize that the missions afforded under the estimated costs will be ones that respond to the main scientific requirements articulated by the panels in Chapters 5 through 11, but not necessarily all of the desired requirements. The selected missions reflect the panels’ prioritization of scientific observations but are not the result of an exhaustive examination of the trade-offs across the entire range of potential missions. Clearly, more detailed cost estimates are needed that examine the full range of mission trade-offs. Where possible within budget constraints, augmentation of the specified set of science observations with additional desired observables should be considered; however, NASA and the scientific community must avoid ‘requirements creep’ and the consequent damaging cost growth” (National Research Council, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, 2007, p. 43).
7 The discussion between the ESD director and the committee took place on April 28, 2011, during the committee’s first meeting in Washington, D.C. Discussions with mission team members took place during the committee’s first and second meetings, the latter of which was held on July 6-8, 2011.
8 The bulk of early formulation funding went directly to the science community to support “requirements gathering.” Without pushback from engineering or cost experts, requirements can accumulate with minimal challenges or controversy. The sense is that the science is paramount and, as long as the mission is far in the future, anything is considered possible. However, this approach nurtures the development and maintenance of sometimes inappropriately high expectations and can result in untenably high costs and high cost risk.