James Webb Telescope sun shield snags, further launch delays likely

Enlarge / NASA’s James Webb Space Telescope was placed in Johnson Space Center’s historic Chamber A for vacuum testing on June 20, 2017. (credit: NASA)

A new report on the James Webb Space Telescope has found that ongoing technical issues with final testing and assembly of the $8.8 billion project will probably cause the launch date of the oft-delayed instrument to slip again to the right. Presently, NASA is targeting June 2019 for launch aboard an Ariane 5 rocket.

The US Government Accountability Office published the report on Wednesday. It concluded, "Given several ongoing technical issues, and the work remaining to test the spacecraft element and complete integration of the telescope and spacecraft, combined with continuing slower-than-planned work at Northrop Grumman, we believe that the rescheduled launch window is likely unachievable."

The report catalogs a number of issues that Northrop Grumman has dealt with during the integration process, particularly the technical challenges and workforce issues needed to meet them. For example, the report cites a worrying problem that cropped up during one of the tests to deploy the telescope's essential sunshield—one of its six membrane tensioning systems experienced a potentially crippling "snag."