During a recent test, NASA encountered new hardware problems with the James Webb Space Telescope (JWST).
According to SpaceNews, Greg Robinson, the JWST program director, said in a meeting in Washington DC on May 3 that the problem was due to “screws and washers” coming off during recent environmental testing. “Right now we believe that all of this hardware – we’re talking screws and washers here – come from the sunshield cover,” he said.
The incident is in line with others that have already drastically pushed the project’s completion date. The launch had initially been planned for October 2018. But thanks to recurring errors in the telescope’s design and assembly, the earliest launch date is expected to be in May 2020.
Dennis Andrucyk, deputy associate administrator for science at NASA, had stated in a briefing that the biggest problem had been with the thrusters of the spacecraft that will carry the JWST. Technicians, he said, had damaged seals in valves of the thrusters by cleaning them with “incorrect solvents”. So the valves had to be refurbished, setting the project back by nine months.
Additionally, pressure transducers in the propulsion system had been damaged when workers applied the wrong voltage, costing another three months.
The JWST has a large sunshield made of an ultra-thin material, to protect it from sunlight in space while it conducts its observations. This sunshield tore in several places during testing. According to Andrucyk, engineers are currently investigating the root cause.
In light of these troubles, NASA has commissioned an independent review of the JWST’s launch readiness under Tom Young, a former director of the NASA Goddard spaceflight centre. The review is expected to be completed by the end of May 2018.
NASA has also sent more people to the Northrop Grumman facility in Redondo Beach, California. This is where the JWST telescope will be assimilated with the larger spacecraft.
These delays are expected to have dire financial consequences for the mission. The US Congress had already set an $8 billion spending limit on the mission in 2011. This cap is at risk of being breached now.
Some scientists believe that spending more on the JWST could reduce the amount of money available for other NASA projects. One such is the flagship Wide Field Infrared Survey Telescope (WFIRST). Despite some scepticism at first, Congress had approved $150 million for WFIRST in its 2018 fiscal bill, along with some criticism about the need for it.
Paul Hertz, director of NASA’s astrophysics division, had said earlier this month, “We think it’s likely that we will [launch the JWST], but we don’t have the data in hand to establish a new cost.” He added that they were not 100% confident of breaching the $8 billion-mark either.
While repeated testing costs money, it could only work out better for the JWST in the long run. Once it is launched, the JWST will be inaccessible for repairs should anything go wrong later. This is because its final location, from which it will study the universe, will be about 1.5 million km from Earth.
NASA administrator Robert Lightfoot had said at a recent teleconference that JWST was the highest priority project for the agency’s Science Mission Directorate. At the same time, Thomas Zurbuchen, the NASA associate administrator for science, had said, “The stupidest thing we could is to somehow rush to a deadline.”