The Nancy Grace Roman Space Telescope is a next‑generation NASA observatory focused on wide‑field infrared surveys of the cosmos, including precision cosmology and exoplanet discovery, with launch planned no later than May 2027 and operations from the Sun–Earth L2 region. NASA Science. Roman is named for astronomer Nancy Grace Roman and succeeds the mission concept formerly known as WFIRST. NASA.

Management and Partnerships

Roman is managed by Goddard Space Flight Center, with the Space Telescope Science Institute (STScI) serving as Science Operations Center and Caltech/IPAC as the Science Support Center; JPL leads the Coronagraph Instrument. NASA Science; STScI; IPAC. STScI’s contract for Roman science operations extends through September 30, 2027 to support pre‑launch through the first year of operations and data archiving. NASA.

Launch and Orbit

Roman is planned to launch on a SpaceX Falcon Heavy from Kennedy Space Center, with a program baseline of launch no later than May 2027. NASA GSFC – Observatory Technical. The observatory will operate in a halo orbit around the second Sun–Earth Lagrange point (L2), about 1.5 million km from Earth, to provide a thermally stable, unobstructed view of the sky. NASA Science – Roman Observatory.

Observatory and Instruments

Roman carries two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). NASA GSFC – Instruments & Capabilities.

• –Wide Field Instrument (WFI): a ~300‑megapixel near‑infrared imager and slitless spectrometer using an 18‑detector H4RG focal plane with 0.11 arcsec/pixel sampling and a 0.281 deg² field of view; wavelength coverage spans approximately 0.48–2.3 μm with imaging filters and prism/grism spectroscopy modes. NASA GSFC – WFI Technical v1.3 (Aug 2025). The WFI field of view is roughly 200 times Hubble’s WFC3‑IR while retaining comparable spatial resolution. NASA GSFC – WFI Technical.
• –Coronagraph Instrument (CGI): a high‑contrast imaging and spectroscopy technology demonstration designed to directly image and characterize exoplanets, targeting raw contrasts on the order of 10⁻⁸ with active wavefront control and deformable mirrors. NASA JPL; NASA Science – ExEP Technology. The CGI will pioneer techniques needed for future missions such as the Habitable Worlds Observatory. NASA JPL.

The primary mirror is 2.4 meters in diameter, leveraging hardware lineage from an NRO telescope donation announced in 2012 that enabled an upgrade from earlier WFIRST designs. The Washington Post.

Science Objectives and Surveys

Roman’s science program addresses three principal areas: dark energy and cosmology, exoplanets, and broad infrared astrophysics enabled by large‑area, high‑cadence surveys. NASA Science – Roman Mission Page. During its five‑year prime mission (ten‑year goal), the WFI observing program is organized into Core Community Surveys (CCS) and competitively selected General Astrophysics Surveys. NASA GSFC – Observatory Technical; NASA GSFC – Observing Programs & Surveys.

• –High‑Latitude Wide‑Area Survey (HLWAS): multi‑tiered imaging and slitless spectroscopy over >5,000 deg² combining Y/J/H imaging with grism spectroscopy to measure weak gravitational lensing, galaxy clustering, baryon acoustic oscillations (BAO), and redshift‑space distortions. NASA GSFC – Core Community Survey Definition; NASA GSFC – HLWAS.
• –High‑Latitude Time‑Domain Survey (HLTDS): time‑domain imaging and prism spectroscopy to discover and characterize Type Ia supernovae and other transients for precision expansion‑history measurements. NASA GSFC – Core Community Survey Definition.
• –Galactic Bulge Time‑Domain Survey (GBTDS): high‑cadence monitoring toward the Galactic bulge to detect exoplanets via microlensing, including sensitivity to cold, wide‑orbit, and free‑floating planets; nominal 12.1‑minute cadence seasons and complementary low‑cadence and snapshot components. NASA GSFC – GBTDS; NASA GSFC – Core Community Survey Definition.

Community survey planning and oversight were conducted through definition committees and the Roman Observations Time Allocation Committee (ROTAC), which issued recommendations in April 2025 on survey balance and time allocation, including reserving approximately 25.5% of WFI time for General Astrophysics Surveys. NASA GSFC – Core Community Survey Definition.

CGI observations will demonstrate direct imaging and spectroscopy of giant exoplanets around nearby stars, advancing coronagraphy performance beyond that on the Hubble Space Telescope and James Webb Space Telescope by incorporating active wavefront sensing and control. NASA JPL; NASA Science – ExEP Technology.

Development History

The mission originated as WFIRST, the top large space priority of the 2010 National Academies decadal survey New Worlds, New Horizons, which recommended a wide‑field infrared survey telescope for dark energy and exoplanet microlensing. National Academies Press; NASEM – WFIRST/AFTA Review. NASA renamed WFIRST in May 2020 to honor Nancy Grace Roman. NASA.

By late 2024 and early 2025, Roman completed major integration milestones, including joining the telescope and instruments to the spacecraft and entering comprehensive environmental testing; NASA reported the mission was on track for completion by fall 2026 and launch no later than May 2027. NASA; NASA Science – Roman Mission Page.

Data Volume and Community Access

Roman’s ground system—led by STScI (Science Operations Center), with Goddard operating the Mission Operations Center and IPAC serving as Science Support Center—is designed to process and archive over 20 petabytes in the first five years, with daily downlink rates vastly exceeding those of Hubble; nominal spacecraft data volume is about 11 Tbits/day. NASA; NASA GSFC – Observatory Technical. Public data access and proposal/grants management (including General Astrophysics programs) are provided via STScI and IPAC, with responsibilities divided between WFI imaging (STScI) and WFI spectroscopy and microlensing plus CGI operations (IPAC). STScI; IPAC.

Relationship to Other Facilities

Roman’s wide‑field infrared surveys complement targeted high‑resolution studies by James Webb Space Telescope and provide cosmological datasets synergistic with Euclid and ground‑based wide‑field facilities such as the Rubin Observatory. National Academies Press; NASA GSFC – HLWAS.