How to bid on the 2026 Astrophysics Small Explorer (APSMEX) for NASA

What NASA is buying and why it matters

NASA is seeking proposals for the 2026 Astrophysics Small Explorer (APSMEX) program. This is a significant opportunity for firms involved in astrophysics research and development, as it contributes to NASA's Science Mission Directorate objectives. Vendors should review the full Announcement of Opportunity (AO) for complete details on the scope of work.

Key dates and deadlines

The solicitation was published on August 06, 2026. The final deadline for proposals is September 09, 2026, at 11:59 PM ET. It is crucial to note that earlier important dates, such as for a mandatory Notice of Intent and a virtual Preproposal conference, are mentioned in the full announcement and attachments on NSPIRES. Interested parties must review these documents carefully to avoid missing critical steps.

Questions regarding this opportunity must be sent via email to both the primary and alternative points of contact listed in the solicitation. Ensure that "APSMEX26" is included in the subject line of your email.

Who this opportunity suits

This opportunity is best suited for professional organizations with expertise in astrophysics, space science, and related engineering fields. Firms capable of developing and proposing small explorer missions for scientific research will find this relevant. The solicitation is categorized under professional services, indicating a need for specialized scientific and technical capabilities.

How to access and respond to the solicitation

To access the full solicitation, you need to visit the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES). The solicitation number is NNH26ZDA011O. You can find it by clicking on "Solicitations" on the NSPIRES landing page and then entering the number in the search box.

It is essential to download and review all attachments, including the "6AugustEmail.pdf" and "9JuneEmail.pdf" files mentioned in the SAM.gov update. These documents contain critical information, including details about the mandatory Notice of Intent and the virtual preproposal conference. You may need a free account on NSPIRES to view all documents.

Tips for a competitive response

Given the nature of this astrophysics program, a competitive response will demonstrate a deep understanding of NASA's scientific goals and technical requirements for small explorer missions. Clearly articulate your proposed mission's scientific merit, technical feasibility, and management plan.

Pay close attention to all instructions within the Announcement of Opportunity, especially those related to the mandatory Notice of Intent and any preproposal conferences. Adhering to all submission guidelines and deadlines is critical. Ensure your proposal addresses all evaluation criteria outlined by NASA, providing clear and concise evidence of your team's capabilities and experience in relevant areas.