NASA plans single-step selection for 2026 Astrophysics SMEX AO

The NASA Science Mission Directorate (SMD) has issued a third Community Announcement via SAM.gov updating a draft Announcement of Opportunity and saying it intends to solicit investigations for the Astrophysics Explorers Program in the second quarter of calendar year 2026. SMD’s Astrophysics Division plans to release an AO titled “2026 Astrophysics Small Explorer (SMEX)” during the 2nd quarter of CY 2026.

The announcement says the final APD SMEX 2026 AO text will differ from the previously released draft to incorporate an initiative to improve proposal evaluation and mission development efficiency. The expected key differences include a single-step selection process for investigation proposals, no competitive Phase A studies, and a nominal projection of 18 months for the combined Phase A&B concept development and preliminary design.

The competition aims to select a single proposal to proceed as a NASA project in Phase A per NASA Procedural Requirements (NPR) 7120.5. The CA notes that some items marked Deferred in the Draft SMEX 2025 AO will not be deferred in the Final AO.

Key Topics

Science, Nasa, Astrophysics Smex, Explorers Program, Phase A, Langley Research Center