Webb bumped to 2021, and no one is breathing easy
By Amanda Miller|June 28, 2018
Scientists were disappointed by NASA’s announcement Wednesday that the schedule for completing and launching its Webb telescope will be pushed out to 2021 from 2020 due to manufacturing and testing errors. What might be most troubling for scientists is that the experts who reviewed the program for NASA suggested that other errors could lurk in parts of the telescope that have already been assembled.
Two of the problems were discovered “later in the development phase than they should have been, with subsequent large impacts,” according to the James Webb Space Telescope Independent Review Board Report released by NASA on Wednesday. “These experiences raise the possibility of other such issues remaining in the design at this stage.”
NASA, in its summary, highlighted what it called “a central finding of the IRB that the development of this telescope should move forward.”
Northrop Grumman, which is assembling Webb, which is also known as JWST, in California, said it has “learned from the recent challenges of the integration and test phase of the program and implemented the necessary corrective actions. We have put the people, processes and tools in place to be successful and help prevent further issues.”
The IRB recommended ways for “improving team morale” among personnel working on Webb’s integration and test phase. “An extended period of second shifts combined with overtime” have taken their toll, according to the board.
The IRB estimated that the delays will add another $800 million to the cost of Webb’s development, bringing the development total to $8.8 billion and the total lifecycle cost to $9.66 billion. NASA is now targeting March 2021 for launch, having already pushed it back from 2018.
The mistakes reported by the IRB included misuse of a solvent to clean propulsion system valves, which “had to be removed from the spacecraft, repaired or replaced, and reinstalled.”
In another instance, wrong wiring in a test “caused excess voltage to be applied to transducers. The error resulted from an improper interpretation of a process step. The error should have been detected by the inspector, who did not inspect, but relied on the technician’s word that he had done the wiring correctly.”
In a third error, fasteners for Webb’s sunshield membrane came loose in an acoustic test.
The IRB characterized each error’s impact to cost and schedule as “substantial.”
For the scientists readying research for launch, delays can mean rearranging an entire career plan, said the University of Arizona’s George Rieke, who leads the science team for Webb’s Mid-Infrared Instrument, or MIRI — in other words, Webb’s camera and spectrograph. Rieke and six others are analyzing data from the Spitzer Space Telescope to model the type of data they think they’ll get from Webb — viewing fainter objects, farther away, in more detail — and then figuring out how to analyze it.
As a member of the science team, Rieke has about 200 hours of guaranteed time using the new observatory. During part of it, he wants to find out whether astronomers have been missing a lot of active galactic nuclei in their observations — the bright core of galaxies where emissions add up to a lot more than their individual stars should account for.
Having been on the Spitzer science team for the past 20 years, though, Rieke takes the long view.
“There was not a single scientist that dropped off the mission in that 20 years,” he said.
The data is worth the wait.
In the meantime, the IRB has recommended that Northrop Grumman Aerospace Systems add staff to “achieve more realistic work schedules,” moving from six-day to five-day work weeks among other corrective actions, such as implementing a “failure-proof ‘safety net’” of independent oversight.
An independent audit will look for existing-but-undiscovered, or “embedded,” problems, and the contractor will bring back to the project what it dubs “responsible design engineers” to take ownership of a component throughout development to launch.
To further raise morale, the IRB recommended periodic science lectures for Webb personnel and their families.
In the Northrop Grumman photo, engineers and technicians unfold and separate the five sunshield layers of the James Webb Space Telescope.