The $4.3 billion space telescope Trump tried to cancel is now complete

“We don’t have moments of terror during deployment,” Townsend said. “Obviously launching is always a risk, the alert rates you have when you separate from the launcher… Then obviously opening the aperture door to get it deployed is another. But those seem like normal aerospace risks, not unusual and distressing for Roman.”

It also helps that Roman uses a primary mirror donated to NASA by the National Reconnaissance Office, the U.S. government’s spy satellite agency. The NRO had originally ordered the mirror for a telescope that would peer into Earth, but the spy agency no longer needed it. Before NASA got its hands on the surplus mirror in 2012, scientists working on the preliminary design of what became Roman envisioned a smaller telescope.

The larger telescope will make Roman a more powerful tool for science, and the NRO’s donation has eliminated the risk of a problem or delay in making a new mirror. But the advantage meant NASA had to build a more massive spacecraft and use a larger rocket to accommodate it, increasing the cost of the observatory.

Testing of Roman’s components went well this year. Work on Roman continued at Goddard until the government shutdown in the fall. On Webb, engineers discovered one problem after another as they tried to verify that the observatory would work as intended in space. There were leaking valves, tears in the Webb’s sun visor, a damaged transducer, and loose screws. With Roman, engineers have found no “significant surprises” in ground testing so far, Townsend said.

“What we always hope when you do this final round of environmental testing is that you’ve squeezed the material out at the lower levels of assembly, and it looks like, in Roman’s case, we’ve done a spectacular job at the lower level,” she said.

With Roman now fully assembled, Goddard’s attention will turn to an end-to-end functional test of the observatory early next year, followed by electromagnetic interference tests and another round of acoustic and vibration tests. Then, perhaps around June of next year, NASA will ship the observatory to Kennedy Space Center, Florida, to prepare for launch on a SpaceX Falcon Heavy rocket.

“We’re really in the final phase of environmental testing for the system,” Townsend said. “We’ve definitely already had the worst environment until we can launch.”