Today, NASA announced that it accepted the findings and recommendations of an independent review of progress toward the launch of the James Webb Space Telescope, intended to be NASA's next great observatory. As a result of some changed procedures and reining in some unjustified schedule optimism, the changes will mean that Webb won't be launched until March of 2021, a delay that will tack on $800 million to the telescope's $8 billion price tag.

Complexity and errors

The James Webb Space Telescope would be the most complex imaging hardware that NASA has attempted to put into space. It features a large mirror that will be formed by multiple individual segments moving into place and protected by a sunscreen that would also unfold after launch. Webb's instruments would be sensitive to a region of the infrared that should allow it to image everything from the Universe's first galaxies to the atmospheres of nearby exoplanets.

But so far, that complexity has driven extensive delays. Early this year, the Government Accountability Office released a report that suggested that further delays were inevitable. And shortly after its release, NASA disclosed that testing of the spacecraft's unfolding resulted in damage to some of the systems. That set the stage for an independent review board to give the entire project a new look.

The board's review and NASA's response were released today. The board paints a picture of significant dysfunction, even as it provides 32 recommendations for minimizing the impact of further problems in the future.

The problems come largely from the work of Northrop Grumman, which is building the spacecraft and its sun shield. Incidents detailed in the report include using a solvent to clean valves without checking with the valve manufacturer; the improper solvent damaged the valves and forced their replacement. In another case, managers relied on the word of a single technician that test wiring was installed properly. As a result, hardware was exposed to excess voltage.

In a final case, fasteners for the sunscreen weren't tightened sufficiently prior to testing under simulated launch conditions. Over a dozen of them popped loose, several ended up inside the spacecraft body, and two of them still haven't been definitively located. During a press call today, the chair of the review board, Tom Young, estimated that these instances alone pushed the launch back by six months at the cost of roughly $1 million a day.

Embedded problems

The press gave NASA administrators ample opportunity to express anger with Northrop Grumman, but they mostly declined. Thomas Zurbuchen, an associate administrator of NASA's Science Mission Directorate, admitted that "I'm not happy to be sitting here telling this story." But he went on to say that NASA had oversight and therefore takes responsibility. Questions about whether Northrop Grumman would be financially penalized for the problems were answered without putting any dollar figures on the consequences.

Young described how the review had identified a series of problems, including human errors, embedded problems, lack of experience, excessive optimism about the schedule, and the complexity of the spacecraft. Of these, he said the most significant were human error and embedded problems. "Because humans are involved, you can expect errors," Young said, but there are procedures that could catch the errors quickly and minimize their impact.

Embedded problems are substantially more complex, as they represent work done years before that has set the stage for problems that will be difficult to detect prior to testing or—perhaps devastatingly—after launch. When asked about the prospects of further embedded problems we haven't detected, Young said, "I don't think anybody can tell us today."

To limit the impact of these issues, the review board made a total of 32 recommendations, including systems designed to ensure that changes are checked multiple times so that human errors can be caught before they do damage or become embedded ones. The report also calls for a detailed audit of what's actually been done in order to identify any other embedded problems that have some sort of paper trail.

Overall, NASA agrees. "By setting this new launch date, NASA is accepting the [board's] recommendations" said Zurbuchen. In fact, the agency has already implemented a number of them and is in the process of implementing 30 of the 32. The remaining two are more complicated and still under review (the PDF linked above notes NASA's responses to each recommendation). Stephen Jurczyk, a NASA associate administrator, said that the work had been underrunning its budget and NASA will be able to use its current funds to handle implementing the changes in 2019. But, he adds, the agency will have to ask Congress for more in 2020.

At this stage, the Webb's science-instrument package and the spacecraft itself are still being tested individually. The major test of these changes will come when the two parts of the spacecraft are integrated into the final hardware that will be sent into space.