TABLE 1.1 Statistics from the Most Recent Astrophysics Small Explorer (SMEX) Rounds
|AO||Cost Cap (FY15$) No LV||Proposals Received||Selectable Proposals (Category I-II-III)||Category IV Proposals||Science Driver for Category IV?||Cost Driver for Category IV?||Other TMC Driver for Category IV?|
|2003 SMEX||$119 million||16||9||7||5||1||2|
|2007 SMEX||$116 million||17||8||9||6||6||5|
|2014 SMEX||$125 million||13||6||7||5||2||5|
NOTES: Out of the 23 selectable proposals, 9 were Category I, 12 were Category II, and 2 were Category III. AO, announcement of opportunity; SMEX, Small Explorer; TMC, technical, management, and cost.
SOURCE: NASA. See Appendix C.
Finding 1-1: The number of selectable/submitted proposals varied significantly by subfield (high energy: 15/22, UV/Visible/Near-IR: 7/18, Other: 1/6).6
Finding 1-2: The 2014 solicitation resulted in a smaller number of proposals than in the previous round (2007), but this may just be a statistical fluctuation. If the upcoming call results in another drop, further investigation may be warranted.
Finding 1-3: In the three most recent rounds, there were approximately a factor of 7 more Category I and II SMEX proposals than there were launch opportunities.
Conclusion: There is no shortage of compelling science to be done with SMEX missions.
The science return from recent SMEX missions has been excellent, with GALEX (launched in 2003) and NuSTAR (launched in 2012) providing compelling examples of frontier science performed by missions at this scale. These missions were cited in more than 1,000 refereed astrophysics publications.7
DISCUSSION OF COMMUNITY INPUTS
Community responses to the Request for Information (RFI, see Appendix B) are compiled in Appendix C. The committee received a small number of responses, which, while informative, cannot be assumed to be representative of the entire community. As such, instead of counting the responses as votes, the committee carefully considered the ideas in each response as a check on its analysis.
On the main question of SMEX science opportunities, the responses were not unanimously in favor of another call. These respondents remarked upon limitations in optics at this mission scale and preferences for different-sized missions, larger and/or smaller. Other respondents were in favor of another call, and some suggested changes to the mission line. The committee considered these positions among the rest of the input it received as well as its own analysis.
Other aspects of the community responses are highlighted as discussed below.
7 A search on the Astrophysics Data System (ADS) bibliographic service for these two mission names in the abstract resulted in more than 1,000 refereed publications.