Physics of the CosmosROSES-25: D.8 HWO Precursor Science Investigations 30 July 2026NOIs Due 10 September 2026, Proposals Due 26 October 2026The Habitable Worlds Observatory (HWO) is a large-aperture ultraviolet/visible/near-infrared observatory concept recommended by the National Academies of Science, Engineering, and Medicine decadal survey, “Pathways to Discovery in Astronomy and Astrophysics for the 2020s” (Astro2020). The HWO mission concept would be the first space mission designed specifically to search for life outside our solar system and would be capable of performing transformative science across astrophysics, areas of planetary science, and more. Habitable Worlds Observatory Precursor Science Investigations (HWO-PSI) program element D.8 of ROSES aims to advance the scientific foundation that would reduce risk for a potential future HWO mission. ROSES-2025 Amendment 68 releases D.8 Habitable Worlds Observatory Precursor Science Investigations (HWO-PSI) as a new opportunity in ROSES-25. Please direct questions concerning D.8 HWO-PSI to Megan Ansdell at Megan.C.Ansdell@nasa.gov.