2026 Astrophysics Small Explorer Announcement of Opportunity
24 March 2026
March 2026 Community Announcement
https://explorers.larc.nasa.gov/APSMEX26/SMEX/index.html
The NASA Science Mission Directorate (SMD) is releasing a fourth Community Announcement (CA) via www.SAM.gov as an amendment to a special notice number NNH25ZDA008J stating NASA’s intention to solicit proposals for the Astrophysics Explorers Program in Calendar Year (CY) 2026. SMD’s Astrophysics Division’s (APD) Explorers Program continues to plan on releasing an Announcement of Opportunity (AO) entitled “2026 Astrophysics Small Explorer (SMEX)” during the 2nd Quarter of CY 2026. This CA provides an update on the AO Cost Cap. The AO Cost Cap will be increased to $190M in FY 2026 dollars (FY26$) from $170M in FY 2025 dollars (FY25$) as in the draft AO.
Along with answers to questions previously submitted by the Community, a copy of this email update also has been posted by the NASA Science Office for Mission Assessments (SOMA) to their 2026 Astrophysics SMEX Acquisition website and are available at https://explorers.larc.nasa.gov/APSMEX26/SMEX/index.html
New questions and/or comments about Astrophysics SMEX 2026 (APD SMEX26) AO should be addressed via email to John Wisniewski, Astrophysics Small Explorers Program Lead Scientist, SMD, john.p.wisniewski@nasa.gov, and E. Lucien Cox, Astrophysics Small Explorers Program Executive, SMD, elbert.l.cox@nasa.gov, using subject line:
“APD 2026 SMEX CA.”
Emailed questions and/or comments will be accepted until April 3, 2026, 11:59 p.m. Eastern time. Depending on the nature of the question(s) or comment(s), NASA may respond on an individual basis by email or may post responses in an update to the Questions and Answers (Q&A) on the SOMA 2026 Astrophysics SMEX Acquisition website. Anonymity of persons or institutions submitting questions will be preserved.
Before the Final AO text is released, NASA does not plan to release another draft version of the APD SMEX26 AO. The APD SMEX26 Acquisition website Q&A page is the forum to communicate answers to questions about the AO prior to its release. The APD SMEX26 Pre-proposal Conference will provide an opportunity ~3 weeks after the release of the Final AO to clarify expectations on the Single-Step Selection approach planned for proposal evaluation. After the AO release the Q&A feature on the APD SMEX 2026 Acquisition website will continue to provide a resource for clarifications.
Previously submitted questions and their respective answers can be found here:
https://explorers.larc.nasa.gov/APSMEX26/SMEX/pdf_files/APSMEX26_QnA_Rev21.pdf
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