Roman telescope measures optical error below its requirement

NASA reported on Oct. 14 that engineers completed a major checkout of the Nancy Grace Roman Space Telescope’s Wide Field Instrument and adjusted the telescope’s focus. The instrument measured 63 nanometers RMS of optical error, below its approximately 90-nanometer requirement.

NASA characterized the result as nearly 30% better than the team predicted. The approximately 90-nanometer figure is a requirement, not a prediction of the instrument’s measured performance. The measurement followed instrument testing and focus adjustments during commissioning.

NASA’s Roman mission is managed at Goddard Space Flight Center in Greenbelt, Maryland. The measurement is a commissioning result; it does not mean Roman has begun routine science observations or made a scientific discovery.

NASA said coronagraph light-blocking tests were planned for the coming weeks but did not give a date. Roman launched on Aug. 30, 2026, and NASA anticipated the telescope’s first images by early 2027.