NASA SHARPENS ROMAN TELESCOPE'S WIDE FIELD INSTRUMENT

NASA says engineers have brought the Nancy Grace Roman Space Telescope’s Wide Field Instrument into sharper focus, with image quality nearly 30% better than predicted. They adjusted its secondary mirror by about one-sixteenth the width of a human hair. The mirror directs light from the telescope’s primary mirror towards the instrument’s detectors. Engineers reduced a measured optical error from about 90 nanometres to 63 nanometres, compared with an initial allowance of about 90 nanometres.

The Wide Field Instrument uses 18 detectors with a combined resolution of about 300 megapixels. After activating the instrument in September, engineers tested the detectors and the electronics that operate them. They also checked a rotating wheel whose filters select wavelengths of light and separate incoming light into its component colours. Further tests covered the thermal control system and calibration LEDs, which provide adjustable light for checking the detectors’ response.

“All of Roman’s sweeping surveys will rely on the Wide Field Instrument,” said Dave Hickey, a systems engineer at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland. NASA says the telescope’s planned surveys include research into dark matter and dark energy. Engineers are continuing work on its other main instrument, a coronagraph designed to suppress starlight. That instrument aims to allow direct photographs of distant planets outside the Solar System.