Roman Wide Field Instrument Hits 30% Better Image Quality After In-Orbit Alignment

Engineers at Goddard completed detector checks, element-wheel verification, internal LED calibration, and thermal control validation on the 18-detector mosaic. Only small actuator tweaks were required because ground testing at L3Harris and BAE had already placed the optics within tolerance. The result exceeds the 10% margin built into survey exposure-time calculations for weak-lensing and supernova cosmology programs.

Sharper PSF directly improves shape measurements for the high-latitude survey and reduces systematic floor in the supernova survey by tightening photometric redshift scatter. Compared with JWST's narrower but deeper NIRCam imaging, Roman's 0.28 square-degree field now offers higher survey speed at equivalent resolution, a combination that was not fully credited in the 2020 mission design review.

The performance margin also relaxes thermal-stability requirements during the five-year prime mission, potentially allowing longer continuous observations of the Galactic bulge microlensing field. Next steps include final flat-field maps and a two-week focus-sweep test before the first public imaging release scheduled for early 2027.