The head of NASA’s Science Mission Directorate hinted today that more delays may be in the offing for the James Webb Space Telescope (JWST). While progress is being made integrating the spacecraft and its instruments at prime contractor Northrop Grumman, Thomas Zurbuchen is worried about the time it is taking and an agency-level assessment is underway to determine whether the March 2021 launch date is realistic.

Zurbuchen provided an update on JWST to the Science Committee of the NASA Advisory Council (NAC) this morning. He recently visited Northrop Grumman and was impressed at the magnitude of the effort required to build the telescope, which is often described as the follow-on to the Hubble Space Telescope. JWST and Hubble study the universe in different bands of the electromagnetic spectrum (Hubble is primarily an optical telescope while JWST operates in the infrared), but both are designed to unravel the mysteries of the universe.

Originally envisioned in the late 1990s as a $1 billion telescope, by last year the cost had grown to $8.8 billion for development (not including operations). That breached a congressionally-imposed cost cap of $8 billion that was established in law after substantial cost growth and schedule delays in the early part of this decade. After rebaselining the program in 2011, NASA promised the telescope would launch in October 2018, but by late 2017 it was clear that date would not be met due to integration problems at Northrop Grumman.

NASA established an Independent Review Board (IRB), chaired by Tom Young, that concluded the earliest possible launch date was March 2021. NASA calculated the new development cost estimate at $8.803 billion, a 10 percent increase, which is surprising so late in a program. Adding in operations, the revised life cycle cost is $9.663 billion. The costs do not include launch. The European Space Agency agreed to launch JWST on an Ariane V rocket as part of a cooperative agreement with NASA at no cost to NASA. Canada is also a partner in the project.

The House Science, Space, and Technology Committee held a two-day hearing following the IRB report where Northrop Grumman bore the brunt of the committee’s displeasure. In the end, however, Congress increased the cap to $8.8 billion considering that $7 billion had been spent already and the scientific potential of the data JWST will produce is indisputable.

The mantra became “Webb is worth the wait.”

The IRB report spelled out what had gone wrong and what needed to be done to ensure the telescope works properly once it is launched. There are no second chances for JWST. Unlike Hubble, JWST is not designed to be serviced by astronauts (or robots) and will not be located in Earth orbit. It is headed to the Sun-Earth L2 Lagrange point 1 million miles (1.5 million kilometers) away.

That was Zurbuchen’s point this morning. In a recent visit to Northrop Grumman where JWST passed a sunshield deployment test, he was impressed at the progress being made, but cited “close to a dozen issues that we’re working.”

“My worry at this moment in time is just the time we’re taking. … Our March ’21 launch date is the launch date that we’re heading towards and we’re currently in the process of our agency-level assessment of that to really see how likely that launch date is and … beyond that, financial reserves and so forth. I know if you are an astrophysicist you want us to absolutely test this spacecraft absolutely well [and not] launch in March [2021] with problems. — Thomas Zurbuchen

In an email this afternoon, a NASA spokesperson told SpacePolicyOnline.com that although “issues have been revealed during testing that have reduced the schedule margin,” NASA continues to work towards the March 2021 launch date. “Mission success depends on rigorous testing.” NASA is “confident” in the success of JWST and there are no plans to reconvene the Independent Review Board.