NASA revealed today that launch of the $8 billion James Webb Space Telescope (JWST) will slip from October 2018 to March-June 2019 because spacecraft integration is taking longer than expected. After experiencing repeated cost overruns and schedule delays during the 2000s, NASA restructured the program in 2011 and vowed it would meet the newly established launch date of October 2018. That date now has slipped again, although NASA insists it will not increase costs.

JWST was the top priority for a new large space telescope to follow the Hubble Space Telescope in the 2000 Decadal Survey for astrophysics. Decadal Surveys are conducted by the National Academies of Sciences, Engineering and Medicine about every 10 years (a decade) to identify science priorities for each of NASA’s science disciplines (astrophysics, planetary science, earth science, heliophysics, and life and physical sciences in space).

Another astrophysics decadal survey was completed in 2010. Implementing its recommendation for the next in the series, the Wide-Field Infrared Space Telescope (WFIRST), was delayed because the funds were required for JWST instead.

Early cost estimates for JWST were in the $1 billion-$3.5 billion range, but grew to $4.5 billion by 2005. Costs continued to grow and the schedule slipped. By 2010, it was estimated to cost $5.1 billion with launch in 2014.

Senator Barbara Mikulski (D-MD) demanded an independent review to ferret out the reasons. At the time, she chaired the Senate Appropriations subcommittee that funds NASA and was an ardent supporter of NASA, especially programs like JWST that are managed by Goddard Space Flight Center in Maryland. She retired last year.

The independent review was headed by John Casani, a veteran project manager at the Jet Propulsion Laboratory. The Casani report blamed poor management as the fundamental problem. It estimated JWST would cost $6.5 billion with launch no earlier than September 2015. A subsequent internal NASA review led to a rebaselining of the program in 2011 with an even higher cost estimate — $8 billion — with launch in October 2018. The NASA cost and launch estimates included reserves to cover unexpected problems.

Congress supported the rebaselined program, but cost-capped it at that $8 billion. The cap does not include operations or launch. The European Space Agency (ESA) is providing the launch as part of a cooperative no-exchange-of-funds agreement with NASA.

NASA and Congress have kept a close watch on the program since then. Until today’s announcement, it appeared that all was well. The only potential hiccup was that ESA might need the October 2018 Ariane launch slot for one of its own missions that has a constrained planetary launch window, which could have meant a JWST launch slip to February 2019.

Today’s statement announcing the delay to March-June 2019 makes no mention of the ESA launch conflict. The delay is attributed entirely to the complexity of integrating the various parts of the spacecraft.

Thomas Zurbuchen, the head of NASA’s Science Mission Directorate, was quoted in the announcement as saying the change is “not indicative of hardware or technical performance” but “the integration of the various spacecraft elements is taking longer than expected.” While thermal testing of the telescope and its science instruments that is taking place at Johnson Space Center “continues to go well,” NASA’s statement says, the “spacecraft itself, comprised of the spacecraft bus and sunshield, has experienced delays during its integration and testing at Northrop Grumman in Redondo Beach, California.” Northrop Grumman is the prime contractor for JWST.

At congressional direction, the Government Accountability Office (GAO) conducts its own annual assessments of JWST. In its most recent report, issued in December 2016, GAO identified integration and testing as the “riskiest phase of development.”

Today’s NASA statement asserts that “[e]xisting program budget accommodates the change in launch date, and the change will not affect planned science observations.”

NASA did not inform the public of the delay through it’s usual method of issuing a press release. Instead, the information was simply posted on a NASA website about the JWST program.

Zurbuchen testified before the Space Subcommittee of the House Science, Space, and Technology Committee this morning about last month’s total solar eclipse and the upcoming launch of the Parker Solar Probe. He did not mention the JWST delay at the hearing, although NASA did brief committee staff prior to the announcement according to a committee spokesperson.

Committee chairman Lamar Smith (R-TX) said in a statement to SpacePolicyOnline.com that JWST “is a crucial project and an investment in our future. The news of the delay is certainly disappointing, and I hope the JWST is completed and launched as close to on schedule as possible so we can look forward to the incredible discoveries it will bring.”

Smith is a strong advocate of astrophysics and has held a number of hearings on the topic, especially the discovery of planets around other stars (exoplanets) and the search for life elsewhere in the universe. Locating and studying exoplanets is one of JWST’s scientific objectives.