In a report released late February, the Government Accountability Office warned that the highly anticipated James Webb Space Telescope is likely going to face significant delays. This was the sixth report of its kind, annually assessing the status of the telescope and delivering an update to the US Congress. This update discussed the likelihood of delays pushing the telescope’s launch back even further than its projected date of June 2019. These delays could result in the project greatly exceeding its cost cap.

Initially, NASA scheduled the launch for October 2018, and for several years, the anticipated launch date stood. Unfortunately, certain aspects of the telescope were being developed slower than previously expected, a decision was made to push the date back to sometime between March and June of 2019. A more precise date has not been announced, as an independent test is required to gauge the readiness of the telescope. Thruster issues and problems with the sunshield deployment were cited as the cause of the delay. The sunshield in particular created an unanticipated, but lengthy, delay, as it took nearly two months to refold.

During the refolding process, engineers noticed numerous tears and other imperfections in the material caused by worker errors. While they can be repaired, this takes additional time. To meet the expected launch date, the company has started to operate around the clock, with three shifts working on the necessary upgrades and repairs. The report highlighted that these efforts are still likely to result in delays, as the telescope has nearly five times fewer staff members than it did less than a year ago.

This delay gave Northrop Grumman, the manufacturers, four extra months of scheduling reserve time. Schedule reserves are stretches of time between the completion, testing, and approval of a spacecraft and its launch. By scheduling reserves like this, developers have a bit of leeway if there are last minute adjustments that need to be made as a result of testing. Four months generally offers plenty of reserve time. However, almost immediately after the initial delay was announced, Northrop Grumman stated that they need three of those four months to complete work.

Report authors do place some of the blame for the delays at NASA’s feet. They believe that NASA should have followed up on an earlier recommendation suggesting an updated joint cost estimate be filed with Congress. While NASA agreed with this suggestion in December of 2012, they failed to follow through. Had they done so, they may have been able to prevent some of these more costly delays.

Northrop Grumman’s need for additional time leaves just one and a half months of schedule reserve. The authors of the report believe that this is insufficient, given the nature of the prior delays and the type of tests that are required to move forward. They concluded the report by telling Congress that further delays are likely and that the project is in jeopardy of going over its $8 billion cost cap.