The Space Reviewin association with SpaceNews
 


 
JWST
The optical assembly of the James Webb Space Telescope, including both its segmented mirror and instruments, emerged from a thermal vacuum chamber test late last year. At the time the mission was scheduled for launch between March and June of 2019, a date that has now slipped by about a year. (credit: NASA/Chris Gunn)

A tangled Webb of delays


Bookmark and Share

For several years, NASA’s James Webb Space Telescope had been held up as a shining example of a major program brought back on track after delays and cost overruns threatened it with cancellation. A “re-plan” of the telescope in 2011 set a 2018 launch date for the mission and a cost cap of $8 billion. That was much later, and more expensive, for the giant space telescope, but also more realistic.

“With all the flight hardware 100 percent complete, we’re approaching the finish line for launch readiness. However, it looks like we have a ways to go before we cross that finish line,” Zurbuchen said.

For years after that re-plan, JWST remain on schedule and budget, making slow but steady progress both for its unique segmented optical system as well as the spacecraft and giant deployable sunshield. As recently as a year ago, everything still seemed to be on track for a launch on an Ariane 5 from French Guiana in the fall of 2018.

In the last half year, though, the situation has drastically changed. In late September of 2017, NASA announced it was delaying the launch from October 2018 to some time between March and June of 2019. Issues with the spacecraft and sunshield had taken longer to resolve than expected, consuming the schedule reserve for a late 2018 launch (see “More problems for big space telescopes”, The Space Review, October 30, 2017)

“The change in launch timing is not indicative of hardware or technical performance concerns,” Thomas Zurbuchen, NASA associate administrator for science, said in a statement then announcing that delay. “Rather, the integration of the various spacecraft elements is taking longer than expected.”

In the months that followed, NASA said it would develop a revised launch date, more specific than that May-to-June window, in early 2018, after reviewing the progress made on resolving those technical issues.

At the end of February, the Government Accountability Office (GAO) weighed in with a warning: based on the limited schedule reserves available to the program, even after taking into account the delay to 2019, more delays were likely. It blamed continued problems with spacecraft and sunshield, including deployment tests that resulted in tears in the five-layer sunshield membrane.

The slip to March-June 2019 was covered by the program’s budge reserves, NASA officials previously said, but further delays could exhaust them. “Under the 2011 replan, Congress placed an $8 billion cap on formulation and development costs, but any long delays beyond the new launch window—which, as noted above, are likely—place the project at risk of exceeding this cap,” the GAO report concluded.

“At this stage in the project, a few extra days or weeks or even months of schedule delay, or the expenditure of some additional dollars, is a small price to pay to ensure success of a mission as important as JWST,” Young said in December.

Last week, the bad news arrived for JWST’s launch date arrived. In a press briefing March 27 called on less than 24 hours’ notice, Zurbuchen and other agency leaders, including acting administrator Robert Lightfoot, announced that the telescope’s launch was slipping by yet another year, to “approximately” May 2020.

“With all the flight hardware 100 percent complete, we’re approaching the finish line for launch readiness. However, it looks like we have a ways to go before we cross that finish line,” Zurbuchen said. “Tasks are just taking longer to complete, and there have also been a few mistakes.”

The latest delay again centered on issues with the spacecraft bus and sunshield. (The telescope optics and instrument package, which passed thermal vacuum tests last year at the Johnson Space Center, was shipped to Northrop Grumman’s facility in California in February to wait for the spacecraft to be ready.) NASA said it was a mix of new problems with those spacecraft elements, as well as a better understanding of the scope of previous problem, that led to the new delay.

An example, he said, was the thruster problems, linked to contaminated valves that had to be refurbished. “We actually didn’t know what that impact would be at the time” when the problem was discovered last summer, said Dennis Andrucyk, deputy associate administrator of NASA's science mission directorate.. That valves were successfully refurbished, he said.

The sunshield is another example, he said. Deploying and then stowing the sunshield took far longer than expected, and also created a number of tears in the membrane linked to slack in cables used in the deployment system. Those issues will be addressed, but two more deployment tests are planned, with little guarantee that they can be done much more quickly than the first one.

In response to this latest delay, NASA announced a set of managerial changes that would take place, intended to improve oversight of the mission. This included more direct reporting between project managers and agency leadership, and more NASA personnel assigned to Northrop Grumman’s facilities to oversee work there. At Northrop Grumman, the company’s manager for JWST work now directly reports to the president and chief operating officer. A few days later NASA also reassigned personnel, moving Greg Robinson, the deputy associate administrator for programs in NASA’s science mission directorate, into the role of JWST program director; Eric Smith, who had been program director, will become program scientist.

JWST
The JWST optical assembly is suspended in a clear room at Northrop Grumman’s facility in southern California, awaiting assembly with the spaceraft bus and sunshade. (credit: NASA/Chris Gunn)

The revised launch date of May 2020 remains only approximate for now since additional reviews are planned. That includes a new independent review board that will be chaired by Tom Young, a former director of NASA Goddard and later president of Martin Marietta at the time of its merger with Lockheed.

Young, at a December hearing by the House Science Committee on JWST and other space telescopes, said at the time he was not concerned about what was a roughly six-month delay in the mission to 2019. That included, he said, spending any extra money needed to ensure that the mission is a success.

“JWST is at a point in its development where the only criterion that is important is mission success,” he said at that hearing. “At this stage in the project, a few extra days or weeks or even months of schedule delay, or the expenditure of some additional dollars, is a small price to pay to ensure success of a mission as important as JWST.”

How many additional dollars remains to be determined. Young’s independent board is scheduled to start work this week and finish by late May. NASA plans to submit a report to Congress by late June with a revised estimate of the launch date and overall development cost, including if that exceeds the $8 billion cap set by Congress back in 2011.

The assumption is that, with the delay, the cost will breach that cap, although in the announcement NASA only said that the spacecraft “may exceed” the cap. Any breach of that cap, even by one dollar, would trigger a requirement for Congress to formally reauthorize the mission within 18 months.

“WFIRST and Webb are as similar to each other as the Malibu that I drive and the Ferrari my neighbor drives,” Zurbuchen said.

“We think it’s likely that we will, but we don’t have the data in hand to establish a new cost,” Paul Hertz, director of NASA’s astrophysics division, said of the potential for a cost breach during a meeting of the National Academies’ Committee on Astronomy and Astrophysics March 28. “We’re not 100 percent confident that we’re going to breach that $8 billion.”

Even if it does, the impact of that additional money on NASA’s overall budget, and for its astrophysics division, remains unclear. Hertz noted that, for fiscal years 2019 and 2020, that may mean simply shifting funding in current and projected budgets intended for telescope operations into development. That could limit the amount of additional money needed in those years to cover the development overrun.

“I don’t believe it will be a large impact,” he said of the effects of the delay on NASA’s overall astrophysics program, citing that shift of planned JWST funding from operations to development, expecting that no additional funding would be needed until fiscal year 2020. “The amount of money we need in FY20 will be modest compared to the whole astrophysics budget.”

However, he acknowledged that the shift of funds planned for operations of JWST to its development would count against its $8 billion cap, and could cause a breach. It would also count against the overall lifecycle cost of the mission, including its development and operations, because of the delay in its launch and thus delay in starting operations.

Some members of Congress reacted strongly to the delay. Rep. Lamar Smith (R-TX), the retiring chairman of the House Science Committee, called the delay “disappointing and unacceptable” in a statement. “I expect it to be completed within the cap and launched as close to on schedule as possible so we can look forward to the incredible discoveries it will bring,” he said.

Most members, though, said little about the delay (it being announced while Congress was on spring break no doubt helped.) And few believe that, with the JWST as far along as it is, it faces any risk of not being reauthorized by Congress and given the additional funding needed.

A bigger concern, though, is what it means for other “flagship” NASA science missions (or, as the agency now prefers to call them, “large strategic” missions.) The next astrophysics flagship mission, the Wide-Field Infrared Survey Telescope (WFIRST), is now facing its own near-death experience, as NASA’s 2019 budget proposal seeks to cancel it (see “Will WFIRST last?”, The Space Review, February 19, 2018). Congress suggested it would not go along with that, giving WFIRST $150 million in the 2018 omnibus spending bill approved last month along with language criticizing any effort to cancel missions identified as priorities in decadal surveys by the scientific community. That came before the announcement of the latest JWST delay, though.

“It’s very unpleasant,” Rieke said of the delay delay. “This is a much longer delay than any of us have anticipated, and there will obviously be various consequences.”

In the briefing announcing the JWST delay, and a speech at the National Academies’ Space Science Week later the same day, Zurbuchen sought to clarify the differences between JWST and WFIRST. “There’s going to be an impact of perception,” he acknowledged. “Cost control relative to WFIRST is all about scope, and controlling and understanding scope. Cost control for Webb is all about executing and integrating new technologies towards a new mission that frankly we’ve never done.”

Or, as he explained, “WFIRST and Webb are as similar to each other as the Malibu that I drive and the Ferrari my neighbor drives. They’re both cars, but they’re really different classes of both cost and complexity.”

Astrophysics, though, isn’t the only NASA science division that undertakes flagship missions. Its planetary science division currently has three in various stages of development: Mars 2020, Europa Clipper, and a Europa lander mission (the last a mission still in its earlies phases of development but well-funded by Congress, despite NASA not requesting any money for it.) Mars 2020 is also the first step in a multi-mission Mars sample return effort that will later require one mission to retrieve the samples and send them into orbit, and another to collect the sample contained and return it to Earth. Each of those additional missions could have the cost and complexity associated with a flagship-class program.

The impact for those other flagship missions remains to be determined, but for now astronomers are trying to come to grips with the latest JWST delay. The announcement came just days before the deadline for submitting proposals for the first cycle of JWST observations. The Space Telescope Science Institute, which will handle science operations of JWST, said shortly after the NASA announcement that the deadline would be pushed back to no earlier than February 1, 2019. Any observing proposals that had been submitted would need to be resubmitted once a firm, revised deadline was set.

“It’s very unpleasant,” said Marcia Rieke of the University of Arizona, co-chair of the Committee on Astronomy and Astrophysics of the National Academies, interrupting a discussion about WFIRST at the committee’s meeting March 27 to announce the JWST delay. “This is a much longer delay than any of us have anticipated, and there will obviously be various consequences.”

Those consequences could include delays to the next astrophysics decadal survey, planning for which was staring to ramp up in order for it to be completed in late 2020. The timing of the survey had been tweaked to incorporate initial findings from JWST that could influence planning for future space- or ground-based observatories the report might recommend developing.

With JWST now delayed to May 2020, and likely not commissioned until late 2020, Zurbuchen suggested that the decadal also be delayed. “We recognize that the timing of the decadal is a multi-stakeholder type of discussion,” he said at the Space Science Week meeting. In his opinion, though, “we should flip planetary and astrophysics and move astrophysics to the right.” With the next planetary science decadal not expected to be completed before 2022, that would likely delay the astrophysics decadal to perhaps 2024.

Not everyone is on board with that. “I would assume just not delay it a couple of years,” said Anne Kinney, head of the NSF’s mathematics and physics sciences directorate, at the Committee on Astronomy and Astrophysics meeting March 28. NSF is also involved in the decadal given its role developing and operating ground-based observatories. “From NSF’s perspective, let’s keep going.”

At the Space Science Week meeting, Zurbuchen’s comments led to the question of whether its space-based and ground-based elements could be done separately. He was skeptical. “My personal feeling is that’s really dangerous,” he said, since the ground- and space-based astronomical research is deeply linked. “By decoupling the two, you could end up with two halves that don’t add to a full report when all is said and done.”


Home


Space Access '19'