WASHINGTON — As NASA works to keep the James Webb Space Telescope on track for a 2021 launch, the chairman of the mission’s independent review board believes that the mission was “a step too far” for the agency.

Speaking at a meeting of the Committee on Astronomy and Astrophysics of the National Academies’ Space Studies Board Oct. 29, Tom Young said that while the mission may ultimately be a success, its difficulties provide lessons as NASA considers future large astronomy missions in the next decadal survey.

“I, personally, have come to the conclusion that JWST had too many inventions, too much risk, and was a step too far,” he said at the end of a presentation about the review board’s work.

Young emphasized that he was neither opposed to JWST being completed nor had doubts it could be done successfully. “There are a group people who are diehard supporters of JWST, and there are others who support it, but they’re really angry at the cost growth and the schedule delays,” he said.

“My assessment is that JWST will be supported. I don’t think that there’s any issue in this whole political process that something bad will happen to JWST,” he said. He added, though, that there could be “collateral damage” to other NASA programs, although he declined to predict any specific effects.

He suggested that the lessons from JWST should be applied as NASA considers future large space telescopes for the next decadal survey, which will start soon and be published in late 2020. “I know that we’re embarking right now on missions that could make JWST look small by comparison,” he said, and such missions should keep the JWST experience in mind. “I would say that the next decadal should wrestle with that problem.”

The independent review board chaired by Young came up with 32 recommendations for NASA to implement regarding JWST, spanning a gamut of technical and programmatic issues. These ranged from identifying “embedded problems” within the design of JWST to ensuring that the spacecraft is securely transported from Southern California, where final assembly is taking place, to French Guiana for launch on an Ariane 5.

The board also recommended the NASA’s Launch Services Program apply more oversight to the launch. “We got more pushback on this than almost anything we did,” Young said of that recommendation. NASA, he said, argued that it couldn’t provide the same level of oversight to an Ariane 5 as it would for a typical U.S. vehicle launch because the Ariane 5 launch is being provided by the European Space Agency.

“We said, ‘Baloney,’” Young said. NASA ultimately “bought into” this recommendation, he said, with agency officials meeting with their European counterparts to work out ways for greater NASA oversight of launch activities.

At a meeting of the NASA Advisory Council’s science committee Nov. 1, Greg Robinson, director of the JWST program at NASA Headquarters, confirmed the agency was working on this particular recommendation.

“We’re trying to meet the intent” of the recommendation, he said, including discussions at a technical interchange meeting later in November. NASA Launch Services Program personnel would be able to participate in reviews and examine documentation about the Ariane 5. “We’ve taken it to heart.”

Work on JWST is sticking to a revised schedule announced in June that calls for a launch at the end of March 2021. JWST’s spacecraft element recently completed acoustics testing. “They’re going through the data and everything looks good,” he said. Vibration tests will start in the next two weeks.

NASA accepted and is implementing all the recommendations of the independent review board, Robinson said. The board will reconvene in late November and early December to evaluate NASA’s progress.

The current top-level schedule for JWST still supports a launch of the spacecraft at the end of March 2021. That includes two 60-day schedule reserve periods, one to cover issues with integration and testing of the spacecraft element and the other for the entire observatory. Robinson said there’s also three weeks of schedule reserve for shipping of JWST to the launch site and an additional four months of schedule margin held by NASA Headquarters.

Young, at the earlier meeting, said that the independent review board was unanimous in its belief that JWST should continue, despite its problems, “based on its extraordinary scientific potential and the critical role it has in maintaining and demonstrating United States leadership.”

“If it was a program that did not have the high scientific potential and the U.S. leadership aspects,” he continued, “I think it would be cancelled.”