Technicians work on the James Webb Space Telescope during a test of its Deployable Tower Assembly. NASA confirmed June 10 that the mission will miss its March 2021 launch date because of the pandemic. Credit: Northrop Grumman

WASHINGTON — The head of NASA’s science directorate confirmed June 10 that the James Webb Space Telescope will miss its March 2021 launch date, a slip that was all but inevitable as the coronavirus pandemic slowed work on the spacecraft.

In a presentation to an online meeting of the Space Studies Board of the National Academies, Thomas Zurbuchen, NASA associate administrator for science, said that work on JWST had been going well in months before the pandemic but that the slowdown in work since March made it impossible to keep the mission on its previous schedule.

“We will not launch in March,” he said, which had been the target launch date for the mission. “That is not in the cards right now. It’s not because they did anything wrong.”

When NASA started closing its field centers in March because of the pandemic, personnel that had been overseeing integration and testing of the space telescope at a Northrop Grumman facility in Southern California returned home. Despite initial comments by NASA officials that work would be suspended entirely on the telescope, activities did continue there, including a test announced by NASA June 9 of its Deployable Tower Assembly that separates the mirror from the spacecraft bus.

That work, though, has been at a slower pace than before the pandemic. At a session of an American Astronomical Society meeting June 2, Jonathan Gardner, deputy senior project scientist for JWST at NASA’s Goddard Space Flight Center, said that Northrop at the time had five eight-hour shifts a week devoted to JWST work. Before the pandemic, the company had 12 shifts a week of 10 hours each.

Work had recently started to ramp back up on JWST, with some NASA personnel returning to the Northrop facility and the company preparing to resume a second daily shift. Nonetheless, Gardner said last week the project expected to miss that March 2021 launch date. “We’re expecting a delay,” he said.

NASA hasn’t set a new launch date yet for JWST. “What we need to do is learn the new efficiency” of working in current conditions, Zurbuchen said. “We need to calibrate that through a schedule review and go forward.” A schedule assessment, he said, was planned for July.

He remained hopeful that JWST will still launch some time in 2021 on an Ariane 5 from French Guiana. “I’m very optimistic of this thing getting off the launch pad in ’21.”

That confidence, he said, was based in part on the progress that the mission had been making just before the pandemic. There had been concerns about diminishing schedule reserves, including a Government Accountability Office report in January that warned a launch next March “may not be feasible” given the amount of work remaining and the rate at which the project was using up schedule reserves.

Zurbuchen said that the last quarterly review of JWST, held just before pandemic started shutting down NASA centers, showed that the project had completed all of its planned work in the previous quarter without using any schedule reserve. “Zero reserve days basically means that those teams stayed on their toes and pushed the telescope forward at the maximum speed possible,” he said.

JWST, though, had suffered years of launch delays and billions of dollars in cost overruns, most recently in 2018 when NASA announced the mission’s launch date, which had been October 2018 for several years before slipping the year before to early 2019, had been pushed back to March 2021 while its cost grew 10% to $8.8 billion.

Problems with JWST, along with issues early in the development of the next large astrophysics mission, recently renamed from the Wide-Field Infrared Survey Telescope (WFIRST) to the Nancy Grace Roman Space Telescope, have raised questions about NASA’s ability to manage large, or flagship, science missions. Zurbuchen said at the Space Studies Board meeting that flagship missions remain essential.

“NASA needs to do flagships. We need to learn how to do flagships,” he said, arguing such missions are often the only way to address pressing scientific questions. “The challenge with flagships has been, and we’re spending a lot of effort in learning about it, is to manage them in a way so that they don’t eat the neighborhood.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...