DRAFT Announcement of Opportunity (AO) -- 2025 Astrophysics Small Explorer (SMEX)

Amendment / Modification

• This document serves as a Community Announcement (CA) and an amendment to a special notice, indicating NASA's intent to solicit proposals for the Astrophysics Explorers Program in Calendar Year (CY) 2026.

• It provides an update on the AO Cost Cap, increasing it to $190M in FY 2026 dollars from $170M in FY 2025 dollars.

• Answers to previously submitted questions have been posted on the NASA Science Office for Mission Assessments (SOMA) 2026 Astrophysics SMEX Acquisition website.

• The primary impact is on the cost cap for the "2026 Astrophysics Small Explorer (SMEX)" Announcement of Opportunity (AO).

• New questions and/or comments are accepted via email until April 3, 2026, 11:59 p.m. Eastern time.

• Responses may be provided individually or posted as an update to the Q&A on the SOMA website.

• A pre-proposal conference is planned approximately 3 weeks after the release of the Final AO.

• No further draft versions of the AO are planned before the Final AO release.

Solicitation / RFP / RFQ

This document is a Community Announcement (CA) providing advanced notice of the forthcoming "2026 Astrophysics Small Explorer (SMEX)" Announcement of Opportunity (AO) from NASA's Science Mission Directorate (SMD). The AO aims to solicit investigations for the Astrophysics Explorers Program and is expected to be released in the second quarter of calendar year (CY) 2026. The purpose of this CA is to inform potential proposers of key differences between the draft AO and the final AO, and to provide an update on the solicitation timeline.

• 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 selection process in the final AO will not include competitive Phase A studies, unlike the draft 2025 AO.

• The nominal projection for total duration of the combined Phase A&B concept development & preliminary design is 18 months.

• Specific requirements that will NOT be deferred in the Final AO include:

  • Requirements 49 and 50 for naming the Project Manager and Project System Engineer.
  • Requirements 43 and B-65 through B-69 regarding orbital debris and end of life, consistent with NPR 7120.5's requirement for a preliminary ODAR at KDP-A.
  • Requirement 38 to show compliance to the maximum channel bandwidth.
  • Requirement 75 for a discussion of cost estimate error and uncertainty.

• The Final AO will require draft project-level Level 1 and Level 2 Requirements, consistent with NPR 7120.5's list of products for KDP-A.

• The final AO text will be posted no earlier than April 2026.

• The selection is targeted for the 1st Quarter CY 2027.

• The SMEX launch readiness date is targeted for no later than the 3rd Quarter CY 2031.

• The AO will be posted on the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES).

• A pre-proposal conference is scheduled approximately 3 weeks after the final AO release.

• Notice of Intent is due NET 45 days after AO release.

• Proposals are due NET 90 days after AO release.

• Participation will be open to all categories of U.S. organizations, including educational institutions, industry, not-for-profit organizations, Federally Funded Research and Development Centers, NASA Centers, and other Government agencies and non-U.S. organizations with some restrictions.

• Any costs incurred by prospective investigators in preparing submissions in response to this CA are at the submitter's own risk.

• The forthcoming final AO may contain provisions that differ from this preliminary notice, and those provisions will take precedence.

• Additional information will be posted on the 2026 Astrophysics SMEX Acquisition website: https://explorers.larc.nasa.gov/APSMEX26/SMEX/index.html.

• Questions or comments should be addressed via email to John Wisniewski (john.p.wisniewski@nasa.gov) and E. Lucien Cox (elbert.l.cox@nasa.gov) using the subject line "APD 2026 SMEX CA" no later than February 26, 2026, 11:59 p.m. Eastern time.

Amendment / Modification

• The Announcement of Opportunity (AO) for the Astrophysics Small Explorers Program 2025 Small Explorer (SMEX) release has been postponed.

• The release will now occur no earlier than April 2026, a shift from the previously estimated April 2025 release.

• This postponement is to allow additional time for NASA's Astrophysics Division (APD) to refine the next SMEX AO, ensuring adequate notice and preparation time for potential proposers regarding changes between the draft and final AO text.

• Section 3, "Proposal Opportunity Period and Schedule," of the draft 2025 SMEX AO is affected by this postponement.

• Inquiries regarding the postponement are due by June 20, 2025, and should be sent via email to Doris Daou (Doris.Daou@nasa.gov) and E. Lucien Cox (Elbert.l.Cox@nasa.gov).

• Responses to questions may be aggregated and provided as a single response, either via email or posted on the SMEX Program Acquisition website.

Solicitation / RFP / RFQ

This document is a draft Announcement of Opportunity (AO) for the 2025 Astrophysics Small Explorer (SMEX) mission, released by NASA's Science Mission Directorate (SMD). The program aims to conduct Principal Investigator (PI)-led space science investigations relevant to SMD's astrophysics goals, focusing on discovering the origin, structure, evolution, and destiny of the Universe, and searching for Earth-like planets.

• The document does not detail specific deliverables but outlines the general scientific goals for astrophysics explorer investigations.

• Not specified in this draft announcement.

• The draft AO text will be posted on the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES) at https://nspires.nasaprs.com/external/.

• Bidders can find the draft AO by searching for "NNH25ZDA008J" or using the short URL: https://go.nasa.gov/NNH25ZDA008J.

• Comments on the draft AO are due by February 21, 2025.

• Participation is open to all categories of organizations and institutions, including U.S. and non-U.S. entities, educational, industrial, not-for-profit institutions, JPL, FFRDCs, UARCs, NASA Centers, and other U.S. Government agencies.

• This is a draft announcement for community review and comment only.

• The issuance of this draft AO does not obligate NASA to issue the final AO or solicit proposals.

• Any costs incurred in preparing submissions are at the submitter's own risk.

• Comments and questions should be emailed to Doris.Daou@nasa.gov with the subject line "DRAFT 2025 SMEX AO".

• Responses to comments will be posted on the Astrophysics Small Explorers Program Acquisition website at https://explorers.larc.nasa.gov/APSMEX25/SMEX/index.html.

• The comment period ends February 21, 2025.