2026 Astrophysics Small Explorer (APSMEX)
NASA will fund selected proposals to design, build, and operate a Small Explorer mission in astrophysics, through a mandatory AO competition.
⚑ Mandatory Notice of Intent before the proposal deadline (per attached email/AO). · Preproposal conference is noted in the supplemental email attachment. · AO text must be checked on NSPIRES; this SAM notice is not complete. · NASA astrophysics mission solicitation; focused on mission concept/proposal development and mission implementation rather than basic research.
Unit fits — one characterization, each unit's own rules
| Physical Sciences & Engineering (demo) | 60 good | technical depth: central; funds other (capped) |
| Tom Love Innovation Hub | 30 weak | prototyping/demonstration stage; deep-tech content |
| IPPRA | 15 none | outside portfolio topics; social/behavioral work is none; funds other — not a research fit |
Description
On or after this SAM.gov notice, the final text for the Announcement of Opportunity (AO) 2026 Astrophysics Small Explorer (APSMEX) will be available for download from the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES) at https://nspires.nasaprs.com. Click on the word “Solicitations” at the top of the NSPIRES landing page and then on the next page enter the number “NNH26ZDA011O” in the search box or use the direct URL provided below. This “Description” is not a complete or verbatim summary of the AO. It is the responsibility interested parties to visit and monitor regularly the two listed internet sites (links) for any amendments or other updates. Please also open and carefully read the attached PDF file named “9JuneEmail.pdf”. The 9JuneEmail attachment is copy of the text that NSPIRES sent to Science Mission Directorate (SMD) List Serv subscribers and includes other and earlier, important dates such as for the submission of a MANDATORY Notice of Intent (NOI) and a virtual Preproposal conference that are prior to the listed Date Offers Due. After reading the full AO on NSPIRES, please address any comments and questions only via email to both the primary and alternative points of contact listed and use " APSMEX26” in the subject line.
Eligibility
Applicant restrictions (federal contract). Set-aside: . Notice type: Combined Synopsis/Solicitation. Organization: NATIONAL AERONAUTICS AND SPACE ADMINISTRATION / NATIONAL AERONAUTICS AND SPACE ADMINISTRATION / NASA HEADQUARTERS.
Apply
Proposal brief SEE AN EXAMPLE →
A one-page internal memo: fit assessment, submission requirements, document scaffold, and next steps dated back from the deadline — tailored to your project idea if you add one.
Proposal shell · Federal (generic) conventions SEE A FEDERAL EXAMPLE →
Funder-faithful document skeletons — Federal (generic)'s document set with section headings, page limits, reviewer guidance, and writing prompts; add a project idea to get [DRAFT] starter bullets. Download as .md for Word or Overleaf.