NASA completes assembly of Nancy Grace Roman Space Telescope
Technicians completed construction of NASA’s Nancy Grace Roman Space Telescope when they joined the observatory’s two major segments on November 25, 2025. The mission is slated to launch no later than May 2027, with teams working toward a launch as early as fall 2026, and the observatory will move to Kennedy Space Center for launch preparations in summer 2026.
More than a thousand technicians and engineers assembled Roman from millions of components. The observatory had been built in pieces: the telescope and instruments formed the inner portion, while the outer portion included the outer barrel assembly, deployable aperture cover, and solar panels.
The outer portion passed a shake test and an intense sound blast, and the inner portion underwent a 65-day thermal vacuum test prior to final integration. Roman’s Optical Telescope Assembly includes a 7.9-foot (2.4-meter) primary mirror — the same diameter as Hubble’s main mirror but weighing about 410 pounds (186 kilograms) — and nine additional mirrors.
Light collected by the mirror will feed two science instruments, the Wide Field Instrument (WFI) and the Coronagraph Instrument, allowing the observatory to use both instruments at once. The WFI uses a focal plane array of detectors that will produce 288-megapixel images; each detector has 16 million pixels, and 18 detectors were incorporated into the array with six flight-qualified spares.
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