consideration by the decadal survey implementation advisory committee (DSIAC) recommended in NWNH.6
• Option B: A Joint WFIRST/Euclid Mission. If the budget constraints that have emerged since delivery of the NWNH report are not adequately addressed and a timely WFIRST as originally conceived is not possible (see Option A), one option to accomplish WFIRST’s goals would be a single international mission combining WFIRST and ESA’s Euclid. Either a U.S.-led mission or an ESA-led mission could be consistent with the NWNH report, contingent on whether or not the United States plays “a leading role” and “so long as the committee’s recommended science program is preserved and overall cost savings result” (p. 1-6). Therefore, it would be advantageous for NASA, in collaboration with ESA, to study whether such a joint mission is feasible. Waiting to decide on a significant financial commitment to such a partnership, whatever its form, would allow time for such studies and for the DSIAC to be established and provide guidance on this issue.
• Option C: Commitment by NASA of a 20 Percent Investment in Euclid prior to the M-class Decision. A 20 percent investment in Euclid as currently envisioned and as presented by NASA is not consistent with the program, strategy, and intent of the decadal survey. NWNH stated the following if the survey’s budget assumption cannot be realized: “In the event that insufficient funds are available to carry out the recommended program, the first priority is to develop, launch, and operate WFIRST, and to implement the Explorer program and core research program recommended augmentations” (p. 7-40). A 20 percent plan would deplete resources for the timely execution of the broader range of NWNH space-based recommendations and would significantly delay implementing the Explorer augmentation, as well as augmentations to the core activities that were elements in the survey’s recommended first tier of activities in a less optimistic budget scenario. A 20 percent contribution would also be a non-negligible fraction of the resources needed for other NWNH priorities.
• Option D: No U.S. Financing of an Infrared Survey Mission This Decade. If neither options A nor B are viable due to budget constraints (or if Option A is not viable and Option B is not possible due to programmatic difficulties), and Option C is rejected, the panel concluded that to be consistent with the overall plan in NWNH, any existing budget wedge could go to other NWNH priorities: the next-ranked large recommendation (augmentation of the Explorer program), technology development for future missions, and the high-priority medium and small recommended activities, possibly with the omission of WFIRST. Although an extremely unfortunate outcome with severely negative consequences for the exciting science program advanced by NWNH, this option seems consistent with NWNH, which did not prioritize between its large, medium, and small recommended activities. However, such a major change of plan should first be reviewed by the recommended DSIAC.
Providing strategic advice under current conditions is extremely challenging. Whether today’s changing conditions fundamentally alter the long-term approach of the decadal survey might understandably be questioned. However, the panel emphasizes that the 2010 decadal survey provided integrated advice that was explicitly designed to be robust for the entire decade. The survey anticipated that fiscal and scientific conditions would change. NASA’s rapidly changing budgetary landscape highlights the urgency of establishing a mechanism such as the DSIAC to ensure that appropriate community advice is available to the government. The NWNH recommendations remain scientifically compelling, and this panel believes that the decadal survey process remains the most effective way to provide community consensus to the federal government to assist in its priority setting for U.S. astronomy and astrophysics.
6 In NWNH, the recommended DSIAC was charged to “monitor progress toward reaching the goals recommended in [NWNH], and to provide strategic advice to the agencies over the decade of implementation” (National Research Council, New Worlds, New Horizons in Astronomy and Astrophysics [prepublication], 2010, p. 1-5).