The Nancy Grace Roman space telescope, now assembled at the Goddard Space Flight Center, impresses with its technical specifications and data processing potential. By comparison, Hubble has collected about 400 terabytes of data in 35 years, while Roman could produce 500 each year.
Scheduled for launch in September 2026, eight months earlier than planned, this observatory promises to map the universe like never before. Its ability to capture images 200 times wider than Hubble in a single shot opens up unprecedented possibilities for studying fleeting cosmic phenomena.
Illustration of the Nancy Grace Roman space telescope scanning the universe.
Credit: NASA
Unlike the James Webb telescope, which specializes in the far infrared, Roman will observe in visible and near-infrared light. Its wide-field instrument covers vast portions of the sky with moderate resolution, ideal for detecting rapid events such as radio bursts or supernovae. This panoramic approach will enable unexpected discoveries without having to precisely target a specific region.
Furthermore, Roman is designed to explore the least known aspects of our universe. By mapping billions of galaxies in three dimensions, the instrument will study cosmic expansion and the distribution of dark matter. Scientists hope to thus constrain the properties of dark energy, which accounts for 68% of the universe. It will also measure gravitational distortions caused by dark matter, providing clues about its still unknown nature.
Engineers finalizing the integration of the Nancy Grace Roman space telescope in the NASA clean room.
Credit: NASA/Jolearra Tshiteya An onboard coronagraph will block the glare of stars to directly image exoplanets. This instrument can detect planets 100 million times fainter than their star, a performance 100 to 1,000 times greater than current space coronagraphs. It will be able to observe light reflected by planets similar to Jupiter in size and temperature, paving the way for studying their atmospheres.
After its completion, Roman will undergo final tests before being transported to the Kennedy Space Center. A SpaceX Falcon Heavy launcher will take it to the L2 Lagrange point, about 930,000 miles (1.5 million kilometers) from Earth. This relatively stable location, already occupied by the James Webb and Euclid space telescopes, offers a clearer view than Earth orbit. Commissioning should take a few months.
Preparations included simulations of vibrations, extreme temperatures, and intense noise to ensure the observatory's robustness. Teams are checking the final sensors and the closures of the thermal shields.
The Nancy Grace Roman space telescope during assembly.
Credit: NASA/Michael Guinto