The IXPE GO Program solicits proposals for investigations in any area of astrophysics (not constrained to IXPE’s prime science areas). Individuals may submit proposals for observations that will advance the IXPE mission science return. Observing proposals may be for "standard," "Target-of-Opportunity (ToO)," “Large Program (LP)” or “Multi-cycle” observations. IXPE anticipates executing approximately 1 high (observations begin within 9 days of trigger) and 7 medium (observations begin between 9 days and 4 weeks of trigger) priority triggers in this GO cycle.

The Neutron Star Interior Composition Explorer (NICER) is an X-ray experiment on the International Space Station (ISS) dedicated to high-resolution timing and spectroscopy of rapidly variable X-ray sources in the 0.2–12 keV band. Proposals for NICER data-analysis investigations addressing all areas of astrophysics are solicited, with a limited amount of funding available in GO Cycle 9.

The text for these two opportunities may be found in Sections 9 and 10 of D.3 Combined General Investigator General Observer Program.

Amendment 67 announces a change to the Phase-1 proposal: The work plan previously included in the anonymized scientific justification Section of Phase-1 proposals must now be provided in the Expertise and Resources Not Anonymized document. This supersedes the old instruction in Section 11.2.2, which is now out of date and should be disregarded. New text is in bold and deleted text is struck through, see Sections 9.5 and 10.4. The Phase-1 Proposal due date (submitted via ARK RPS) for both IXPE and NICER remains unchanged at September 17, 2026.

On or about July 27, 2026, this Amendment to the NASA Research Announcement "Research Opportunities in Space and Earth Sciences (ROSES) 2025" (NNH25ZDA001N) will be posted on the NASA research opportunity homepage at https://solicitation.nasaprs.com/ROSES2025and will appear on SARA's ROSES blog at: https://science.nasa.gov/researchers/solicitations/roses-2025/

Programmatic questions concerning IXPE may be directed to Hashima Hasan at hhasan@nasa.gov. Technical questions concerning IXPE may be directed to Kavitha Arur at kavitha.arur@nasa.gov. 

Programmatic questions concerning NICER may be directed to Roopesh Ojha at roopesh.ojha@nasa.gov. Technical questions concerning NICER may be directed to Keith Gendreau at Keith.C.Gendreau@nasa.gov.