Following an independent review, NASA's planned James Webb Space Telescope has received yet another delay in its mission schedule. This time, NASA has moved the target launch from May 2020 to March 2021.
Artist's conception of the James Webb Space Telescope. Illustration: Northrop Grumman (Flickr)
If you're feeling a touch of déjà vu, that's because this telescope has been subject to nearly annual delays and budget increases since its inception in 1996. NASA called for an independent review in April 2018, the results of which have now been released.
The review identified five kinds of problems that have plagued the project. These include human errors, "embedded" problems not identified during inspections and testing, lack of experience, excessive optimism, and the system complexity.
The independent review board's chair, Tom Young, pointed out difficulties with the never-before-built parts, such as the new Sunshield that will filter out radiation from the Sun.
Additionally, the report highlights specific errors that have caused delays. This included a case in which someone used the wrong solvent to clean propulsion system valves. The valves had to be replaced or repaired and put back.
Other mistakes included test wiring that gave too much voltage to acoustic pieces, and lock nuts that were not tightened enough, causing pieces of hardware to come free and fall into the telescope during tests.
The review board concluded that, due to JWST's national and scientific importance, its construction should continue regardless of these mishaps.
It made 32 recommendations for how the project should move forward, including audits, changes in who is accountable for what aspects of the project, making plans for how to bring the telescope to the launch site, and augmenting the testing staff.
The delay will add $US800 million ($1.1 billion) to the telescope's development cost over past estimates, bringing it to $US8.8 billion ($11.9 billion). It puts the total estimated life-cycle cost at $US9.66 billion ($13.1 billion).
The telescope has some very ambitious goals as a flagship mission for NASA. These include peering at exoplanets, studying the most distant galaxies, and other potential projects.
The March 2021 date doesn't account for delays from certain problems, such as Sunshield difficulties, or other new issues that may arise. However, the recommendations aim to actively look for any of these problems existing today to prevent them from significantly affecting the schedule, said Young.
Will there be more delays? It's impossible to say for sure, but Young felt the recommendations, if rigorously implemented, will offer a "high probability of preventing significant schedule impact".
How will US Congress, the US President, and other stakeholders take this latest setback? It's too early to say, said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate. "The science is compelling and remains compelling as we go forward." A Congressional subcommittee recently questioned NASA over these delays in a public hearing.
So, once again, no James Webb Space Telescope yet, but perhaps the new recommendations will make the March 2021 date feasible.