JWST mirror photo

The James Webb Space Telescope in the cleanroom at Northrop Grumman, Redondo Beach, California, in July 2020. [Image: NASA/Chris Gunn] [Enlarge image]

On 16 July 2020, NASA announced that the target launch date for the James Webb Space Telescope—which the agency describes as “the largest, most complex space telescope for astronomy ever built,” and which has been subject to repeated project delays and cost overruns since it was first proposed in the 1990s—will be pushed back once again. The new target launch date will be 31 October 2021, seven months later than the target of 30 March 2021 settled on by the agency two years ago.

This time, for at least half of the seven-month delay, NASA has what would seem to be an iron-clad excuse: the COVID-19 pandemic, which dramatically cut back spacecraft testing activities during April and May and has kept the pace sub-optimal since then. But the agency also admitted that some of the delays stemmed from “technical challenges” and the need to build in some schedule padding to accommodate potential contingencies. NASA doesn’t expect the delay to affect the overall project cost.

Risk assessment

Review of the mission timeline actually started before the coronavirus was an issue, as NASA realized that the project’s schedule reserves—padding built into the previous timeline to cover technical delays—were being consumed faster than expected. Using these reserves was “the exact right thing to do,” according to NASA associate administrator Stephen Jurczyk, “because it was focused on mission success.” But it also, he added, raised “a hard-to-quantify probability that the launch would be missed,” and the agency decided to do a schedule risk assessment to better nail things down.

That risk assessment was itself temporarily derailed by the pandemic—which also led to a dramatic scaling-back of testing activities at Northrop Grumman, in whose California cleanroom the spacecraft currently sits. Cleanroom activities have since ramped up again, with near-full-shift operations starting in late May. But Webb program director Gregory Robinson noted that workers still must observe pandemic social-distancing and masking protocols that tend to make things go a bit slower in the cleanroom.

Robinson suggested that “three-plus months” of the new seven-month schedule delay to October were attributable to COVID-19, with the rest related to the non-pandemic-related scheduling concerns that had prompted the risk assessment in the first place. In pulling together its revised launch target, Robinson said, the team had “factored into the new schedule some inefficiency due to COVID … about 20%.” He acknowledged, though, that the pandemic’s currently uncertain future—including such issues as any potential renewed impact on air travel—clouds things to some extent. “The way things are right now, we have high confidence,” he said. “But we can’t predict the future.”

Cost estimate holds firm

One bit of good news from NASA is that the projected delays won’t affect the overall projected cost for developing the spacecraft, which the agency reported in June 2018 had ballooned to US$8.8 billion dollars. Thomas Zurbuchen, the associate administrator of NASA’s Science Mission Directorate, added that the project’s international partners—the European Space Agency, which will provide the launch vehicle for the spacecraft, and the Canadian Space Agency—remain “fully committed” despite the delay. “We got really good feedback,” said Zurbuchen.

JWST mirror photo

In March 2020, the Webb team successfully tested the full deployment of the observatory’s 6.5-m-diameter mirror, which must launch in folded form and open in space. [Image: NASA/Chris Gunn]

The spacecraft has also passed several significant test milestones in recent months. In March, the full deployment of the telescope’s remarkable 6.5-m gold infrared mirror—which must be launched from Earth folded into sections, and then unfolded into its final configuration in space to extremely tight tolerances—was successfully tested in the cleanroom. And in July, Webb passed its first comprehensive systems test, described by NASA as “a critical software and electrical analysis on the entire observatory as a single, fully connected vehicle.”

Looking ahead, upcoming milestones include so-called environmental testing, including additional acoustic-vibration tests to confirm that the intricate, highly engineered observatory can stand up to the rigors of launch; and testing of deployments of various systems, including a critical sunshield that has created problems in the past.

“Old friends, new eyes”

Even as they announced the delay in the launch date, the NASA personnel strove for an upbeat tone, stressing the pandemic-related hurdles that the testing team had overcome and that the project has continued to move forward. They also were quick to enthuse about what Webb, if successfully deployed, will be able to accomplish.

Program scientist Eric Smith noted that, as with other such projects, the most interesting things to come out of Webb may be things that are “completely unexpected.” He also noted, in response to a question, that one of Webb’s early task will likely be turning its sharp infrared vision on some of the more celebrated targets already scoped out in visible wavelengths by the Hubble Space Telescope. “We’ll be seeing old friends,” he said, “with completely new eyes.”