Roman lifted off aboard a SpaceX Falcon Heavy rocket from Launch Complex 39A at NASA's Kennedy Space Center on 30 August at 07:26 local time. The telescope separated from the rocket's upper stage at 12:58 BST, completing its launch nine months ahead of NASA's original schedule.
Roman carries a 2.4-metre primary mirror matching Hubble's diameter. Its Wide Field Instrument features a 300-megapixel infrared camera with a field of view roughly 200 times larger than Hubble's infrared instrument while maintaining comparable sharpness.
The telescope is headed toward the second Sun-Earth Lagrange point, L2, about 1.5 million kilometres from Earth, where it will operate near the James Webb Space Telescope. The journey will take approximately three months, followed by deployments, activation, calibration and testing before science operations begin.
Roman will survey enormous areas of sky to study populations of galaxies, stars and planets. Its primary science goal involves investigating dark energy by mapping billions of galaxies to trace how the Universe has expanded under dark matter's influence.
Using gravitational microlensing, Roman will conduct a census of planets throughout the Milky Way. When a foreground star's gravity bends light from a distant star, planets around the foreground star produce distinctive signals. NASA estimates Roman could uncover around 100,000 exoplanets, including worlds difficult to detect with other methods.
The telescope also carries the Coronagraph Instrument, a technology demonstration designed to block starlight so fainter planets and debris discs become visible. The demonstration could eventually help future telescopes directly study Earth-like planets.
Roman's primary mission lasts five years, with sufficient propellant potentially allowing another five years. First science images are expected in early 2027.