The heart of NASA’s Nancy Grace Roman Space Telescope was recently delivered to Ball Aerospace in Boulder, Colorado for integration into the Wide Field Instrument (WFI). This is called the FPS (focal plane system) and forms the core of Roman’s camera. When the mission launches in May 2027, astronomers will use the system to gather brilliant images that will help unravel the mysteries of dark energy and dark matter, discover exoplanets, and explore many topics in infrared astrophysics.

FPS consists of a wide array of detectors and associated electronics. The detectors were developed by engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and Teledyne Scientific & Imaging in Camarillo, California. The Goddard team also designed the electronics and built the FPS. Each of Roman’s 18 detectors has 16.8 million tiny pixels that will provide the mission with excellent image resolution. Through these “eyes” we will be able to peer through the dust and vast fields of space, creating high-resolution panoramas of the universe.

“The Roman focal plane array is one of the largest ever flown in a space observatory,” said Mary Walker, director of Roman WFI at Goddard. “Its creation is the result of years of innovation by a dedicated team that looks forward to Roman’s incredible scientific results.”

Once the FPS is loaded into the spacecraft’s WFI (camera), technicians will continue to build by integrating the vehicle’s coolers.

“Detectors need to operate at minus 288 degrees Fahrenheit or minus 178 degrees Celsius for optimum performance,” said Greg Mosby, a research astrophysicist and Rome detector researcher at Goddard. “The Roman detectors are so sensitive that nearby large-field components also need to be cooled, or their heat will saturate the detectors and effectively blind the observatory.” Radiators direct waste heat from instrument components away from the detectors into the cold space, making Roman sensitive to weak signals from distant galaxies and other space objects.

Once the radiators are installed, Roman’s room will be ready for thermovacuum testing this summer. The team expects the entire WFI to return to Goddard in the spring of 2024 and eventually be integrated into the rest of the observatory.