“We don’t have moments of panic to deploy,” Townsend said. “Obviously, launch is always a risk, you have tip-off rates when you separate from the launch vehicle … then, obviously, opening the aperture door so it can deploy. But these feel like normal aerospace risks, not unusual, harrowing moments for Roman.”
It also helps that Roman will be using a primary mirror gifted to NASA by the National Reconnaissance Office, the US government’s spy satellite agency. The NRO had originally ordered the mirror for a telescope that would look to Earth, but the spy agency no longer needed it. Before NASA got its hands on the surplus mirror in 2012, scientists working on the initial design of what would become Roman were thinking about a smaller telescope.
The larger telescope will make Roman a more powerful instrument for science, and the NRO’s donation eliminates the risk of any problems or delays in construction of the new mirror. But the downside was that NASA had to build a more massive spacecraft and use a larger rocket to accommodate it, increasing the cost of the observatory.
Roman’s components have tested well this year. Work on Roman continued at Goddard during the government shutdown in the fall. On the Web, engineers uncovered one problem after another as they tried to verify that the observatory would function as intended in space. There were leaking valves, cracks in Webb’s sunshield, a damaged transducer and loose screws. Townsend said that with Roman, engineers have found no “significant surprises” during ground testing so far.
“When you’re doing this final round of environmental tests we always hope that you’ve screwed down the hardware at the lower levels of assembly, and it looks like in the case of Roman, we’ve done a great job at the lower levels,” she said.
With Roman now fully assembled, Goddard’s focus will turn to end-to-end functional testing of the observatory early next year, followed by another round of electromagnetic interference testing, and acoustic and vibration tests. Then, probably around June next year, SpaceX will fly the NASA observatory to Kennedy Space Center in Florida in preparation for launch on a Falcon Heavy rocket.
“We’re really on the final stretch of environmental testing for the system,” Townsend said. “It’s certainly the worst environment we’ve seen by the time we launch.”
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