WFIRST

The Wide-Field Infrared Survey Telescope, or WFIRST, was a proposed space telescope project by NASA. Its primary goal was to conduct a wide-field survey of the universe in infrared light. WFIRST was designed to investigate dark energy, study exoplanets, and explore a broad range of astrophysical questions. Key scientific objectives included precisely measuring the expansion rate of the universe, determining the cause of cosmic acceleration, and searching for and characterizing exoplanets, including those in habitable zones.

The telescope's design featured a large 2.4-meter primary mirror, similar in size to the Hubble Space Telescope's mirror. This mirror would feed two instruments: a Wide Field Instrument (WFI) for imaging and a Coronagraph Instrument for direct imaging of exoplanets. The WFI was intended to have a field of view significantly larger than Hubble's, allowing it to capture vast areas of the sky efficiently. The Coronagraph was designed to block the light from bright stars, making it possible to detect fainter, nearby exoplanets.

WFIRST was envisioned to build upon the discoveries of previous missions like Hubble and the James Webb Space Telescope (JWST), but with a different scientific focus and observational capabilities. Its broad survey capabilities were expected to yield a wealth of data for astronomers. The project underwent various stages of planning and design, with its mission scope and timeline subject to change based on budget allocations and scientific priorities. In 2022, the mission was renamed the Nancy Grace Roman Space Telescope.