FINAL-- 2021 Astrophysics Explorers Mission of Opportunity (MO), a Program Appendix in the Third Stand Alone Missions of Opportunity Notice (SALMON-3)

The purpose of this SAM.gov amendment is to add a PDF file of an NSPIRES email entitled “A1inSAM” that extends the due date for the mandatory Notice of Intent (NOI) to propose to November 4, 2021. For details please download and carefully read the PDF file. On or after the posting date of this SAM Combined Synopsis/Solicitation Notice, the FINAL text for the Astrophysics Explorers Missions of Opportunity (APEXMO2) Program Element Appendix (PEA), Letter Q, in the Third Stand Alone Missions of Opportunity Notice (SALMON-3) AO may be downloaded from the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES) https://nspires.nasaprs.com by searching on solicitation numbers “NNH17ZDA004O-APEXMO2” or using the attached direct link. Additionally, the “2021 Astrophysics Medium Explorer (MIDEX) Announcement of Opportunity (AO) NNH21ZDA018O” is available in final via the attached direct links. In the event of any future lapses to the NASA operations, AO respondents should visit NSPIRES, the official NASA source for these AOs. Open and carefully read the attached PDF file entitled “21AstroExplorersSynopsisandNSPIRESemail” for other important dates and summary details.