NASA's Nancy Grace Roman Space Telescope is nearing its station more than a million miles from Earth, and early commissioning results suggest it could take sharper images and last longer than designers expected, Live Science reported. The $4 billion observatory, more than 42 feet long, launched on Aug. 30 aboard a SpaceX Falcon Heavy rocket from Kennedy Space Center. It is headed to Lagrange point 2, a gravitationally stable region where it will join the James Webb Space Telescope and the European Space Agency's Euclid. During the journey, which Live Science said was around 85 percent complete at the time of the report, mission scientists have been switching on instruments. The commissioning process has "gone off without a hitch," and the telescope was expected to be ready to start taking in-depth images by the time it arrived, in less than two weeks from that account.
Two post-launch developments have raised expectations further. A series of near-perfect rocket burns, executed during and shortly after launch, saved more than a decade's worth of fuel that can now be used to extend the mission. And after remotely adjusting the telescope's mirror, researchers found it should be capable of snapping images with around 30 percent greater detail than engineers predicted. "It is fantastic to learn that Roman is not just reaching its design goals but exceeding them," Eamonn Kerins, an astronomer at the University of Manchester who will help lead one of Roman's major surveys, told Live Science. Jamie Dunn, director of NASA's Goddard Space Flight Center, said in a Sept. 14 statement that "exquisite planning" and "brilliant execution" made the burns so precise that each one saved up to four years' worth of fuel. The observatory also ended up lighter than planned, which allowed engineers to pack another four years of fuel before launch, said Alison Rao, Roman's propulsion lead at Goddard. In total, those savings could give Roman an additional 12 years of fuel and more than double its planned 10-year lifespan, meaning it could still be capturing images in 2048.
Roman's Wide Field Instrument is a 288-megapixel camera attached to a 7.9-foot (2.4-meter) mirror, with a field of view roughly 100 times larger than Hubble's. After a car-sized mirror was realigned by just one-sixteenth the diameter of a human hair, "all of the images from Roman's cosmic surveys will be even sharper than we expected," Alden Jurling, a senior optical engineer at Goddard, said in an Oct. 14 statement. "Calibrating an instrument is like tuning a piano or guitar before a concert," WFI systems engineer Maxime Rizzo said. Kerins, who is leading the Exoplanet Demographics Working Group for the Transits in the Roman Exoplanets Survey, said the sharper images are exciting but "do not necessarily guarantee that Roman will find more exoplanets than initially predicted." The mission is expected to scour the sky for cosmological targets, including an estimated 100,000 new alien worlds.
Roman's coronagraph, which will block starlight so the camera can try to spot those worlds, has passed its main commissioning phase and is working as intended, according to a NASA blog post cited by Live Science. A global network of ground stations, which will receive up to 1.4 terabytes of data from Roman every day, has established contact with the spacecraft. "What we're seeing now with the actual optical performance and estimated lifetime of Roman is just how good that design process has been," Kerins said. "It's a remarkable achievement." The verified news is better-than-planned optics and a much larger fuel reserve, not a completed sky survey.