Webb telescope at risk of schedule delays, report finds

The Integrated Science Instrument Module (ISIM), center, is part of the James Webb Space Telescope.
The Integrated Science Instrument Module (ISIM), center, is part of the James Webb Space Telescope.(Algerina Perna, Baltimore Sun)

NASA is at risk of falling behind schedule in developing the successor to Hubble Space Telescope, due to be launched in October 2018, a government report found.

All of the major parts of the James Webb Space Telescope have experienced delays in the past year, eating away at time buffers designed to keep the project on track, the Government Accountability Office said in the report. While the $8.8 billion project remains on schedule and within budget, further delays could throw it off, the GAO report said.


NASA officials said they built nearly a year of extra room in the schedule — more than the agency recommends for a mission four years away from launch. NASA's Goddard Space Flight Center in Greenbelt is overseeing the project and much of its assembly.

But government investigators said NASA needs to carefully husband that buffer, given that the telescope is one of the most complex projects in NASA's history and is entering a critical and risky stretch of assembly and testing. While the telescope had significant cost and schedule overruns early in its development, it has remained on track since plans were revamped in 2011.

"The project will have fewer opportunities for the types of workarounds it has been able to incorporate thus far because initiating work is often dependent on the successful and timely completion of the prior work," the report found.

The telescope is to contain four instruments that will allow it to look farther into the universe than humanity has ever seen, observing it as it was just 100 million to 250 million years after the Big Bang. It is one of NASA's top three priorities, the other two being new vehicles for space travel and exploration.

When it was originally planned in the late 1990s, the telescope was to cost $1 billion or less and to launch in 2007 or 2008. But the price tag ballooned as the timetable lagged, until a revised plan was completed in 2011. Since then, the project has remained on track.

But each of the spacecraft's five major elements have experienced delays in the past year, using up three months of schedule buffer over the past 14 months, GAO investigators found. Particularly troublesome was a cryocooler that will keep one of the telescope's infrared light detectors at a temperature only slightly above absolute zero, nearly 450 degrees below zero Fahrenheit.

In one case, for example, work halted for three weeks when a subcontractor investigated possible contamination of one of the cryocooler's compressors. Cryovacuum testing of the telescope component that will contain the four scientific instruments was completed in October after a delay related to a federal government shutdown.

The audit suggests that more hiccups are possible as the various components of the telescope start to come together. Many of the risks could be unknown because NASA hasn't completed a cost and risk assessment of the project since 2011.


NASA officials declined to be interviewed but said in written responses to the report they will complete an updated risk assessment report by the end of February.

Recent work at NASA Goddard has included some assembly of the massive mirrors that will peer into the depths of space and a second cryovacuum test of the instrument module. The telescope's final assembly will take place at a Northrop Grumman facility in Redondo Beach, Calif., before it is ferried through the Panama Canal to a Eurpoean Space Agency launch pad in the South American country of French Guiana.