NASA’s Roman Telescope Successfully Tests Core Systems

A major milestone has been reached by NASA's Nancy Grace Roman Space Telescope after engineers successfully tested its pointing stability and activated its planet-hunting instrument. Between September 15 and 21, the spacecraft's fine-guidance system was evaluated to ensure the observatory can remain locked onto cosmic targets. Shortly after, on September 22, the telescope's specialized Coronagraph Instrument captured space light for the first time.

To achieve extreme precision, the telescope utilizes its Wide Field Instrument, which features 18 detectors. A small portion of each detector is programmed to track specific guide stars with known coordinates. If the observatory experiences tiny drifts during an exposure, the guidance system detects these shifts four times per second and sends coordinates to the attitude control system to make immediate corrections. Without these constant adjustments, the telescope would produce blurry images.

Currently, the system can keep the spacecraft stable to within 1/100,000 of a degree. This is comparable to keeping a laser pointer focused on a small coin from roughly 150 miles away. If engineers optimize the system further, they hope to achieve the same precision from 230 miles away. Unlike other observatories, Roman will also test a unique guidance method that tracks light wavelengths, known as spectra, rather than just relying on stellar positions.

Following these guidance tests, the team activated the coronagraph, which is designed to block intense starlight so that faint, orbiting planets can be observed. The instrument successfully took focused, preliminary images of a star in the Large Magellanic Cloud. Although the initial images contained extra noise because the detectors were kept warmer than normal, scientists confirmed the test was a success. Vanessa Bailey, a scientist at the Jet Propulsion Laboratory, noted that this initial observation confirmed the instrument's ability to generate focused images, paving the way for more complex future tasks.