# NASA's Roman Space Telescope aligns its instruments after launch using test observations of stars

- Published: 2026-11-15 04:52 UTC
- Section: Sky & Space › Astronomy
- Tags: Nancy Grace Roman Space Telescope, Roman telescope alignment, Wide Field Instrument, 18 detectors, Coronagraph Instrument, deformable mirrors, guide stars, telescope stability, NASA space telescope
- URL: https://realtech.media/news/rt-aa7386e6a6c4addda3f47662_nasa_s_roman/

**NASA's Roman telescope has finished aligning its instruments, a step toward science operations. Roman must be at least ten times more stable than Hubble or Webb, says its program scientist.**

![NASA's Roman Space Telescope aligns its instruments after launch using test observations of stars](https://realtech.media/media/2026/11/ef03d09c6e1d753b.png)
*dailygalaxy.com*

According to science.nasa.gov, NASA's Nancy Grace Roman Space Telescope has completed a key milestone: its instruments are now in precise alignment, one more step toward science operations [1]. The team had lined up the optics and instruments on the ground before launch. Launch vibrations, temperature changes and the lack of gravity in space can cause small shifts, so scientists ran a series of test observations to measure them [1].

## Updating the internal map

The measurements were used to update the team's notes on the telescope's anatomy, its "internal map." Scientists observed stars and compared where they appeared in Roman's images with where they were expected. The comparison shows how future observations must be adjusted so that light from the mission's targets falls onto the detectors of the Wide Field Instrument [1].

The 18 detectors of that instrument work together when the telescope locks onto guide stars. According to Tyler Desjardins of the Space Telescope Science Institute, a wrong expected position on any detector creates problems for guiding, so the positions of guide stars must be known very precisely to aim and to correct tiny drifts [1]. Tony Sohn of the same institute said Roman is now internally aligned to within a tiny fraction of a hair's breadth [1]. Dominic Benford, Roman's program scientist at NASA Headquarters, said the observatory has to be at least ten times more stable than Hubble or Webb to do its planned science [1].

## Guiding and the coronagraph

The Wide Field Instrument is both Roman's primary instrument and its guider, tracking stars to help the telescope point and hold steady. While the Coronagraph Instrument images nearby stars in search of planets and dusty disks, the Wide Field Instrument will watch stars in a neighboring patch of sky to keep the observatory steady. Benford noted that this will yield a random sampling of additional deep fields, largely in places that have never had deep surveys [1].

The coronagraph uses a series of masks and other components to block a star's light, and a misplaced component would prevent it from reaching the planned level of suppression. The team adjusted the positions of the secondary mirror, a smaller mirror that connects the telescope to the coronagraph, and the masks and optics inside the instrument [1].

Next, the team will exercise more than 3,000 small moving parts that move the instrument's deformable mirrors. Brian Kern of NASA's Jet Propulsion Laboratory said this approach has been demonstrated in a lab using an artificial space environment. The second stage of active starlight control, with real starlight and real planets, would be a first in space [1].

## Sources

1. [science.nasa.gov](https://science.nasa.gov/blogs/roman/2026/11/13/instruments-on-nasas-roman-space-telescope-get-in-sync-for-science/)
2. [dailygalaxy.com](https://dailygalaxy.com/2026/11/nasas-roman-telescope-reaches-milestone)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-aa7386e6a6c4addda3f47662_nasa_s_roman/