WASHINGTON – NASA’s James Webb space telescope is making continuous progress for an October launch as engineers solve a series of technical problems with the spacecraft, but tackle a new one.
In a March 16 presentation at a meeting of NASA’s Astrophysics Advisory Committee, Eric Smith, JWST program scientist, said engineers had either completed work on completion or were in the process of finishing, several technical issues that had followed the program in recent months none of them posed a risk to the mission’s schedule.
Those issues included concerns about residual air pressure in the spacecraft’s sun canopy that could highlight this when the Ariane 5 rocket that will launch JWST throws its payload fairing overboard. Smith said the problem was resolved after applying a few patches to the lens hood to make sure it could handle double the pressure differential required. Another problem, fasteners on the spacecraft that may not have been installed with enough torque, has also been resolved by re-tightening those fasteners.
The project still has 48 days of planning margin, which Smith said was in line with projections in this development phase. “We’re burning it down at the expected pace,” he said of that schedule margin.
JWST is currently undergoing a final set of implementation tests, including of its primary mirror. The spacecraft will then be prepared for shipment later this summer to Kourou, French Guiana, for final launch preparations.
Smith said the program faces a new technical problem. Two communication transponders encountered separate problems during testing in January. Engineers have tracked down the problems with the two units and have started repairs this week. “Those boxes will be back in time to meet our scheduled ship date,” he said.
That issue, he acknowledged, will use some of the remaining planning margin. “The plan now is that we will get them back in time so we don’t have to use them all,” he said. “That’s the main thing we look at in terms of margin.”
Another problem is the name of the spacecraft itself. The telescope is named after James Webb, the NASA administrator for much of the 1960s who was known for his leadership of the desk during the race to the moon. Earlier in his career, Webb worked at the State Department and is said to have overseen the policy of purging the department of LGBT workers. Some have objected to the name for that reason and have called on NASA to rename the telescope.
Smith said that both NASA chief historian Brian Odom and other historians outside the agency have studied Webb’s activities at the State Department. “They have not yet completed their investigation in the archives, but if they do, the agency would take a position on it,” he said.
Roman delays
While JWST sticks to the October launch date, the flagship’s next astrophysical mission, the Nancy Grace Roman Space Telescope, will likely be delayed due to a slowdown in activity during the pandemic.
“We have COVID effects,” said Julie McEnery, senior project scientist on the mission, formerly known as the Wide Field Infrared Survey Telescope, or WFIRST. In a presentation at the same meeting on March 16, she said the program has been running at “70% efficiency” since the start of the pandemic a year ago, and is likely to remain for several more months as the pandemic slowly fades away.
“The delay is on the order of months, not years,” she said, adding that the pandemic was the only problem facing the telescope. “In essence, Roman is on track. Except for the COVID-related effects, everything comes together and is where it needs to be. “
Paul Hertz, director of NASA’s astrophysics department, told the commission on March 15 that Roman’s launch date would likely shift from late 2025 to mid-2026 due to the pandemic. “It will need additional funding to pay for that schedule form,” he said, but did not estimate those higher costs as the agency is still reviewing estimates of the delay and related costs.