The Government Accountability Office (GAO) released its annual review of NASA’s James Webb Space Telescope (JWST) program today. It reported that according to NASA’s own analysis, the considerably over-budget telescope, already years late, has only a 12 percent chance of meeting its current launch date of March 2021.

GAO is required by Congress to review JWST every year because of its long history of overruns and delays. The cost and schedule were first formally set — “baselined” — in 2009, but had to be rebaselined in 2011 and 2018.

Compared to the 2009 estimate, GAO summed up today that JWST’s cost has increased 95 percent and it is 6.5 years late.

JWST is the follow-on to the popular Hubble Space Telescope, although it will study in the universe in infrared rather than the visible bands of the electromagnetic spectrum. Two other significant differences are that JWST will not be in Earth orbit and is not designed to be serviced by astronauts. Hubble will celebrate its 30th anniversary this year because astronauts aboard the U.S. space shuttle visited it five times to repair it, replace old equipment and install new scientific instruments giving it a new lease on life each time.

JWST will not be that lucky. It is destined for the Sun-Earth L2 Lagrange point 1.5 million kilometers from Earth, too far for astronauts to visit. Not to mention that it is not designed for servicing. Even if crewed or robotic servicing missions became possible, there are no grapple fixtures and the systems and instruments are not designed to be removed and replaced. NASA has added stickers to allow a robotic servicing system to locate JWST just in case future technologies emerge, but it is not part of the plan.

The National Academies of Sciences, Engineering and Medicine recommended JWST, then called the Next Generation Space Telescope, as its top priority in the 2000 Decadal Survey for astronomy and astrophysics. The development cost (not including launch or operations) grew over the years from $1 billion to $8.8 billion, despite an $8 billion cost cap set by Congress in 2011. Congress increased the cap to $8.8 billion last year.

The European Space Agency (ESA) is launching JWST at no cost to NASA as part of a cooperative agreement. If operations are included, the life-cycle cost is $9.7 billion.

Those latest estimates were announced by NASA in 2018 after a review by an Independent Review Board (IRB) established by NASA and chaired by Tom Young. Based on the IRB report, NASA concluded “avoidable errors” by the telescope’s prime contractor, Northrop Grumman, were the primary culprit. Northrop Grumman’s then-chairman and CEO Wes Bush told a congressional committee in 2018 that the company would set aside all the award fee it had earned and could earn in the future on the program until the telescope was activated and demonstrated on orbit.

The scheduled October 2018 launch slipped to March 2021.

In its report last year, GAO recommended that NASA conduct a new Joint Cost and Schedule Confidence Level (JCL) analysis for the program to get a firmer grasp of what remains to be done. NASA adopted that recommendation and it was completed in October 2019.

According to today’s GAO report, NASA’s new JCL analysis concluded the likelihood of meeting the March 2021 date is only 12 percent. Most of the schedule reserves included in the 2018 replan have already been consumed. NASA’s science projects usually are estimated with a 70 percent confidence level that they will be executed within a specific time and cost. The new JCL concludes that a July 2021 launch date meets that 70 percent threshold.

Because of schedule delays resulting from technical challenges coupled with remaining risks faced by the project, the analysis assessed only a 12 percent confidence level for the project’s ability to meet the March 2021 launch readiness date. NASA typically establishes its cost and schedule baseline commitments at 70 percent confidence level. According to the analysis, this 70 percent baseline confidence level is associated with a July 2021 launch date. The project does not currently intend to change the launch readiness date in response to this analysis alone, but plans to assess the feasibility of the launch readiness date again in spring 2020 after significant technical tasks are completed. — GAO

NASA did not publicize the results of the new JCL, but Thomas Zurbuchen, the head of the Science Mission Directorate, hinted that more delays might be in store during a NASA advisory group meeting a few weeks later.

GAO said that in response to the IRB report, NASA has been looking for “embedded risks” that may not have been caught earlier. New risks have been identified, including the following:

bolts found to be deficient in another Northrop Grumman program are installed on JWST and may not meet mechanical strength requirements. JWST has 501 of them that now must pass strength tests and some may need to be replaced;

grounding straps on the spacecraft’s momentum flap came loose during vibration testing and must be removed, repaired and replaced;

a non-explosive actuator needed to unfurl the sunshield did not fire as planned during a September 2019 test and although the 180 actuators are supposed to be electrically redundant, only one of the two mechanisms used to fire the actuator actually worked;

certain membrane retention devices may need to be replaced if testing shows they are not strong enough to withstand pressures expected during launch and flight.

As of October 2019, GAO reports, the JWST project team is tracking 50 risks, three more than at the time of GAO’s last review, of which 12 are moderate concerns. Nine of the 50 risks “are related to the more than 300 single points of failure aboard the observatory.” JWST is a very complex observatory and it must autonomously execute a complicated month-long deployment sequence enroute to its destination.



GAO gave NASA credit for following recommendations in its previous reports and made no new ones this time. It also reported that in October 2019 NASA closed all 32 recommendations made by the IRB, though it did not always adopt the IRB’s approach to resolving them.

With so many billions already spent on JWST and scientists eager for the discoveries it will make, the project does not appear in any danger of cancellation. As its supporters point out, the much beloved Hubble had its own technical, cost and schedule problems, including a defective mirror, that have been all but forgotten with the passage of time. They are hoping the same will be true for JWST.