Caption: Technicians complete the center section of the backplane and backplane support frame for NASA’s James Webb Space Telescope at ATK’s facility in Magna, Utah. Credit: ATK

WASHINGTON — Some work on NASA’s James Webb Space Telescope is behind schedule and fueling concerns about a near-term cash crunch, but the agency still expects to finish the $8.8 billion astronomy flagship in plenty of time to make a scheduled October 2018 launch.

A senior NASA official emphasized that the infrared observatory, which has become infamous for soaring cost growth and delays, is not in any trouble despite the nagging issues cited in the latest annual program assessment by the U.S. Government Accountability Office.

“JWST remains on plan, on budget, on schedule. It’s making great technical progress toward launch in late 2018,” Paul Hertz, director of NASA’s Astrophysics Division, told scientists attending the American Astronomical Society’s winter meeting Jan. 5-9 at the National Harbor, Md.

The GAO, which on Jan. 8 released the results of an audit begun last February and completed in December, concurred, but found that monthly contractor performance on the massive effort declined in 2013, with work taking longer than planned. This trend is eroding near-term reserves and setting the stage for trouble down the road, the report said. 

The congressional watchdog agency also warned that budgetary issues, some beyond NASA’s control, could ultimately jeopardize the observatory’s launch date.

“Several current near-term funding constraints such as low cost reserves, a higher-than-expected rate of spending, and potential sequestration impacts are putting at risk NASA’s ability to meet its cost and schedule commitments for JWST,” the report says.

Congress tasked the GAO in late 2011 to check in annually on JWST to make sure it is staying within the $8 billion development cost cap lawmakers imposed following an independent review that forced NASA to reset the program, nearly doubling its price tag and delaying its launch by 52 months. The JWST program, which the GAO says has about $2.76 billion remaining in its development budget, received $628 million last year, per NASA’s request. 

NASA’s Goddard Space Flight Center in Greenbelt, Md., is managing the JWST program and building the telescope’s Integrated Science Instrument Module (ISIM), a small-room-size structure that will house four instruments furnished by laboratories in the United States, Europe and Canada. Northrop Grumman Aerospace Systems, Redondo Beach, Calif., is the prime contractor for the spacecraft, its tennis court-sized sunshield and the Optical Telescope Element — a deployable 6.5-meter primary mirror and backplane support structure.  

Northrop Grumman also is building the cryogenic cooling system that will keep one of the telescope’s most complex sensors, the Mid Infrared Instrument and its state-of-the-art detectors, at a temperature of minus 266 degrees Celsius. That work is being performed under a separate contract with NASA’s Jet Propulsion Laboratory, the Pasadena, Calif., field center that worked with a European consortium to design and build the Mid Infrared Instrument, which was delivered to Goddard in 2012 and integrated with the ISIM — without the cryocooler — last summer. 

The GAO also found that Exelis Geospatial Systems, the Rochester, N.Y., company helping with JWST integration and testing, in recent months “has been accomplishing less work than planned for the cost incurred.”

NASA’s acting director of the JWST program, Eric Smith, told SpaceNews in November that Webb’s cryocooler is still “a few years” from delivery.

The cryocooler team appears to have solved a valve leak issue by going with replacement valves produced from new materials. But the team — which the GAO says has grown from 40 people to approximately 110 — continues to wrestle with a “cooling underperformance issue” related to the system’s compressor. Northrop Grumman’s cryocooler contract has been modified twice in the last two years, increasing its value roughly 120 percent since March 2012, according to the GAO.

Northrop Grumman, meanwhile, has begun fabrication of some JWST spacecraft components and completed all sections of the Optical Telescope Element’s support structure, which serves as the backbone of the observatory. But the GAO said the project is tracking an issue with release mechanisms that will hold the spacecraft and its unfurlable telescope together during launch atop an Ariane 5 rocket supplied by the European Space Agency. The mechanisms are causing excessive shock vibration when they release in testing. NASA and Northrop are looking at solutions including tweaking the release mechanism’s design, adding damping material and relaxing requirements.  

The GAO credits Northrop Grumman with solving a spacecraft mass issue flagged in 2012 but said that even though JWST has shed its excess 200 kilograms and was under its mass allocation as of November, the project is carrying only about half the 15 percent mass margin Goddard considers standard at this phase of spacecraft development. 

The JWST spacecraft critical design review is getting underway at Northrop Grumman in January with NASA’s 2014 budget unresolved. Congress has until Jan. 15 to replace or extend the stopgap spending measure it enacted last October to end a 16-day government shutdown over sequestration cuts. 

The GAO, which says Congress should consider ordering an updated integrated cost and schedule risk analysis for JWST, is concerned that broader budget issues could undermine NASA’s ability to navigate the several years of fabrication, integration and testing that still stand between JWST and the launchpad. 

“NASA’s ability to remedy these issues will likely be significantly hindered by the potential impacts from sequestration and competing demands from other major projects,” the GAO concluded. “For example, while NASA officials report that the agency was able to absorb the sequestration-related reductions in fiscal year 2013 with relatively no impact on its major projects, including JWST, they indicate that the agency cannot sustain all of its long-term funding commitments at sequester levels in fiscal year 2014 and beyond. Importantly, the JWST project recently began tracking a risk for the budget uncertainty due to sequestration. The risk outlines that there is a potential cut to the JWST budget starting in fiscal year 2014, which could adversely affect the execution of the project’s current plan and potentially jeopardize the October 2018 launch date.”

Follow Brian on Twitter: @Berger_SN

Staff writer Dan Leone contributed to this report from National Harbor, Md.

Brian Berger is editor in chief of and the SpaceNews magazine. He joined in 1998, spending his first decade with the publication covering NASA. He was named senior staff writer in 2004, a position he held...