By Kurtis Archer | 2025-01-24

NASA's Nancy Grace Roman Space Telescope hit a milestone earlier this month, bringing the orbital observatory one step closer to its anticipated launch.

Technicians integrated Roman's payload -- the telescope, instrument carrier and two instruments -- with the spacecraft that will deliver the observatory to its place in space and enable it to function while there, NASA reported on January 8.

"With this incredible milestone, Roman remains on track for launch, and we're a big step closer to unveiling the cosmos as never before," said Mark Clampin, acting deputy associate administrator for the Science Mission Directorate at NASA headquarters in Washington.

Assembly of the Nancy Grace Roman Space Telescope is expected to be completed by the fall of 2026, preparing it for launch by May 2027.

The spacecraft is named after the "mother of the Hubble Space Telescope" and NASA's first chief astronomer, Nancy Roman.

It builds upon the technologies developed and data discovered by both the Hubble Space Telescope and the James Webb Space Telescope.

Revolutionary

Its purpose is to collect valuable information on exoplanets, dark energy, infrared astrophysics, the chronology of existence and the universe in general by measuring the consistency of general relativity, the curvature of spacetime and more.

"It would be quicker to list the astronomy topics Roman won't be able to address than those it will," said Julie McEnery, Roman senior project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, where the observatory is being assembled. "We've never had a tool like this before. Roman will revolutionize the way we do astronomy."

"Roman's much larger field of view will reveal many such objects that were previously unknown," she said in December. "And since we've never had an observatory like this scanning the cosmos before, we could even find entirely new classes of objects and events."

McEnery said the telescope has the potential to "provide a treasure trove of data for astronomers to comb through, enabling more open-ended cosmic exploration than is typically possible."

"We may serendipitously discover entirely new things we don't yet know to look for," she added.

Bigger and better

Roman's primary mirror is the same size as Hubble's primary mirror, but its Wide Field Instrument will capture a field of view that is 100 times greater than that of Hubble's view.

This instrument is an impressive 300-megapixel infrared camera. This will allow Roman to study other galaxies, stars within them, black holes and more.

It will be able to see much more than Hubble and James Webb, and in much shorter periods of observation.

The spacecraft's Optical Telescope Assembly is an integrated system of mirrors and their supporting hardware.

It was built in Rochester, New York, by L3Harris Technologies and delivered to NASA at Goddard.

The large telescope will be the stablest of its size ever built, at least 10 times more so than the James Webb Space Telescope.

Scientists expect to gain data from Roman that will help to answer mysteries about dark matter, dark energy and the universe at large.

Exploring other worlds

The other instrument onboard, the Coronagraph Instrument, will conduct high-contrast imaging and spectroscopy of exoplanets and planet-forming disks.

Its system blocks the intense light from host stars and allows the observatory to see dimmer planets it would otherwise miss.

The sophisticated instruments onboard will be able to analyze the chemical composition of the atmospheres of these other worlds, helping to assess the possibility of life's presence beyond Earth.

This program will mark the first active coronagraph to fly in space.

Rebekah Hounsell, an assistant research scientist at Goddard who is exploring ways to optimize Roman's High Latitude Time-Domain Survey, summarized the value of the telescope.

"Roman will paint a more vivid picture of our universe's past and present, giving us new clues about its possible fate," she said in November 2023. "Its findings could reshape our understanding of the cosmos."

Over the course of the mission's at least five-year lifetime, the telescope will potentially measure light from a billion galaxies, finding thousands of exoplanets and charting their systems.

Many clues as to how the universe expands and functions will be uncovered with the Roman mission, scientists hope.

The European Space Agency, along with Japan, France and space organizations in Germany and elsewhere, will be assisting with components and science support for the Roman.