NASA's Roman Telescope Powers On 300-Megapixel Camera
NASA said on September 15 that the Roman telescope Wide Field Instrument, a 300-megapixel camera, was switched on for the first time, and that its coronagraph passed its first checkout.
NASA announced on September 15 that the team behind the Nancy Grace Roman Space Telescope switched on the Wide Field Instrument for the first time, an infrared camera with 300 megapixels that will serve as the mission’s primary science instrument, and that the same day marked the first checkout of the coronagraph, an instrument built to directly image planets around other stars. A first test image also passed through the instrument, captured while the detectors were still sitting in their launch position, far from final focus.
srpske.rs previously reported that Roman is carrying enough fuel for roughly 22 years of operation instead of the planned ten, leaving the mission far more time for observations. The telescope is designed for wide, deep surveys of the sky and should help astronomers study dark matter, dark energy and planets beyond our solar system. The Wide Field Instrument is expected to capture a patch of sky larger than the apparent size of the full moon, at a sharpness comparable to telescopes like Hubble.
The activation unfolded in stages over several days. The instrument’s heater was switched off on the morning of September 11, starting the cooldown of the detectors toward minus 143 degrees Celsius (minus 225 Fahrenheit). That same evening the calibration system was turned on, and on the morning of September 12 the first test data were sent through the instrument. That evening, in weightlessness, the wheel holding the optical elements, a system of filters and prisms that splits light into individual colors, was tested for the first time. On the morning of September 13 the focusing mechanism was also checked. Over those days the 18 infrared detectors, whose sensitive surface is roughly the size of a laptop screen, cooled down to their final operating temperature of minus 183 degrees Celsius (minus 300 Fahrenheit). Until then the detectors had been held at minus 65 degrees Celsius (minus 85 Fahrenheit) for drying and decontamination.
Josh Schlieder, the scientist in charge of the Wide Field Instrument at NASA’s Goddard center, described the moment in NASA’s announcement:
“After years of effort to build and test the instrument on the ground, we now have confirmation that it works in space. This is a huge milestone for the team at Goddard, for our industry partners at BAE Systems and Teledyne, and for our science centers. There is still a lot ahead of us, but we are on the road to science that opens up new horizons.”
Roman’s coronagraph was switched on slightly earlier, on September 1, in a procedure that began at 7:27 a.m. and ended at 8:22 a.m. Eastern time. It is a system of optics, masks, mirrors that change shape, and sensors designed to block the glare of stars so that the faint light of the planets around them becomes visible. Scientists and engineers at the coronagraph’s operations center, at Caltech/IPAC in Pasadena, California, confirmed they can remotely communicate with every part of the instrument, including its software, thermal control, mechanisms, cameras and the avionics that run them. The coronagraph’s masks, known as shaped pupil masks, are roughly the size of a quarter, and the instrument itself runs at room temperature, 22 degrees Celsius (72 Fahrenheit), far warmer than the Wide Field Instrument’s detectors.
Eric Cady, the optical engineer leading the coronagraph’s commissioning at NASA’s Jet Propulsion Laboratory, explained what comes next:
“Now that this test is complete, we’re doing decontamination: we sit idle with warm detectors, so that anything that has stuck to the surface, like water or traces of chemicals, tends to leave it. That will continue for 30 days, with occasional breaks for other early calibration work.”
These checks confirm that both instruments are working as expected, but they do not mean the science phase has already begun. The coronagraph is now going through a 30-day decontamination period, with occasional pauses for other early calibration tasks, while the Wide Field Instrument still awaits activation of its precision guidance system, along with alignment and fine focusing of the whole telescope’s optics. Roman remains on its roughly one-million-mile (1.6-million-kilometer) journey to the second Lagrange point, and NASA expects to release the first science images in early 2027. Over the mission’s first year and a half, the coronagraph will spend a total of three months observing, aiming to image older, cooler and closer giant planets than the ones direct imaging has mostly turned up so far.
