CAPE CANAVERAL, Fla. — NASA's James Webb Space Telescope faces the high probability of additional delays that could cause the telescope to exceed its cost cap, the U.S. Government Accountability Office warned in a Feb. 28 report.
The report, the sixth in a series of annual assessments of the flagship astronomy mission delivered to Congress, concluded there is little schedule reserve left in in the spacecraft's development, making delays in its launch beyond June 2019 likely.
JWST had been on track for several years for a launch in October 2018. But, in September 2017 NASA announced it was delaying the launch to between March and June 2019 after concluding spacecraft development activities were taking longer than expected. [Building the James Webb Space Telescope: A Photo Tour]
The new launch window gave the mission an additional four months of schedule reserves. However, the GAO noted in its report that not long after announcing the new launch date, project managers learned that Northrop Grumman would need an additional three months "due to lessons learned from conducting deployment exercises of the spacecraft element and sunshield," portions of the overall observatory the company had been working on while NASA was testing its optical system and instruments.
After taking into account "some schedule efficiencies," the GAO said that JWST has 1.5 months of schedule reserve left. "Given the remaining integration and test work ahead," it concluded, "we believe that additional delays to the project's launch readiness date are likely."
Project officials previously said issues with the spacecraft's thrusters and the sunshield, five layers of Kapton material that will deploy to the size of a tennis court after launch to keep the telescope cold, contributed to the slip in JWST's launch from October 2018 to the spring of 2019. Thrusters had to be removed to refurbish faulty valves, while deployment and repackaging of the sunshield took longer than expected.
"The actual harder part is not deploying it, in terms of time, but folding it back together," Scott Willoughby, vice president and program manager for JWST at Northrop Grumman, said of the sunshield in a January interview. "Deploying took a couple weeks, but folding it takes nearly two months."
The GAO report also noted that, during the sunshield deployment exercises, Northrop discovered several tears in the material which it attributed to "workmanship error." Those tears can be repaired but may consume more schedule reserve. A slight change in the design of a membrane tensioning system is planned to correct a snag encountered during a test, but the report said it wasn't known if that would also affect the overall schedule.
Northrop Grumman now has personnel working on JWST in three shifts, 24 hours a day, which the report cautioned "further limits schedule flexibility." The company's workforce devoted to JWST as of last September was nearly five times higher than originally projected, at about 500 full-time equivalent staff. That results in higher costs that erode program reserves.
Additional delays, the report said, could put JWST in jeopardy of overrunning a cost cap of $8 billion established by Congress when it endorsed a "replan" of the mission in 2011, when the mission was in danger of cancellation because of prior cost increases.
"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 concluded in the report.
NASA has not provided an updated schedule for JWST's launch beyond the window of March to June 2019. At a December hearing of the House space subcommittee, Thomas Zurbuchen, NASA associate administrator for science, said an updated launch date would come after an independent review then scheduled for January. The GAO said NASA senior management will formally identify a new launch window after being briefed on the independent review's results in "early 2018."
"The schedule continues to challenge us," said Greg Robinson, deputy associate administrator for programs in NASA's Science Mission Directorate, of JWST during a presentation at the 45th Space Congress here Feb. 28 shortly before the release of the GAO report. "We're going to try and launch it in the next year and a half or so."
The GAO also found that the current challenges facing JWST might have been identified sooner had NASA followed a recommendation from an earlier report to update a joint cost and schedule confidence level (JCL), which it describes as "a point-in-time estimate that, among other things, includes all cost and schedule elements and incorporates and quantifies known risks." NASA had concurred with a recommendation to do so from a December 2012 report, but never followed through.
"An updated JCL may have portended the current schedule delays, which could have been proactively addressed by the project," the GAO report concluded.
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