Roman Space Telescope team lines up its instruments, a step closer to science operations

The team running the Nancy Grace Roman Space Telescope has finished lining up the observatory's optics and instruments in space, it said in a mission blog post on November 13, 2026. The step corrects the small shifts that a launch and a new environment leave behind, and it moves Roman "another step closer to science operations," the post says. Roman, launched on August 30, has been in science commissioning, the last phase before science, since October 22, as our report on Hubble's lens gallery for Roman noted.

Why the map had to be redrawn

Everything was lined up on the ground before Roman left Earth. Shaking during the ride to orbit, swings in temperature and weightlessness can each nudge parts slightly out of place, so scientists have been taking test observations to measure the offsets and update what the post calls Roman's "internal map" of itself. The method is simple in principle: point at stars, note where each one lands in Roman's images, compare that with the predicted spot, and use the differences to correct future pointing, so that light from each target reaches the right place on the Wide Field Instrument's detectors.

The demands are high. Roman "has to be at least ten times more stable than our Hubble or Webb space telescopes" to do its science, said Dominic Benford, the mission's program scientist at NASA Headquarters. Tony Sohn, an astronomer working on Roman at the Space Telescope Science Institute in Baltimore, said the observatory is now aligned "to within a tiny fraction of a hair's breadth of perfection"; the post does not give the result as a number.

One instrument, two jobs

The Wide Field Instrument is both Roman's main camera and its guider: it locks onto stars so the telescope can point accurately and hold still. Its 18 detectors have to work together when they lock on, explained Tyler Desjardins, also of the Space Telescope Science Institute. If the map puts a guide star in the wrong place on one detector, he said, guiding starts to go wrong.

That double role has a side benefit. While the second instrument, the Coronagraph Instrument, stares at a nearby star, the Wide Field Instrument will watch stars in a neighboring patch of sky to keep the observatory steady. Benford said those guiding observations will add up to a random sample of "bonus deep fields", mostly in parts of the sky that have never had deep surveys.

The coronagraph's next test

The coronagraph is built to block a star's glare with a series of masks so that faint planets and dusty disks close to it can be seen. If any of those parts sat in the wrong place, it could not suppress starlight to the degree it aims for, the post explains. For this milestone the team adjusted the positions of the telescope's secondary mirror, of a separate smaller mirror that links the telescope to the coronagraph, and of the masks and optics inside the instrument.

The next job is to exercise more than 3,000 small moving parts that drive the coronagraph's deformable mirrors, which reshape light step by step to reject more starlight while letting a planet's light through. The technique has been shown in a laboratory under simulated space conditions, said Brian Kern, an optical engineer on Roman at NASA's Jet Propulsion Laboratory. Doing it in space with real stars and planets would be "a record-breaking first-time accomplishment," he said; that is still ahead.

No date yet for science

Neither the new post nor the mission's commissioning page says when science operations will begin, and the page notes that the commissioning schedule may change as the team assesses progress. The telescope is named after Nancy Grace Roman, NASA's first chief astronomer, and was called the Wide Field Infrared Survey Telescope, WFIRST, until 2020, the mission's timeline shows. Its surveys are meant to explore dark energy, dark matter and exoplanets, the mission blog says.