WASHINGTON — Concerned NASA is taking too long and spending too much to build its next-generation flagship astronomy mission, U.S. Sen. Barbara Mikulski (D-Md.) is calling for an independent review of how to complete the James Webb Space Telescope (JWST) within budget and on schedule.

In a June 29 letter to NASA Administrator Charles Bolden, Mikulski took the U.S. space agency to task for ongoing cost overruns associated with JWST development, giving Bolden 30 days to assemble an independent review team comprising experts from outside NASA who would report directly to his office.

“I am deeply troubled by the escalating costs for the JWST,” Mikulski wrote in the letter, asserting that while Congress has so far provided all funds requested for the $5 billion successor to the Hubble Space Telescope, an additional $95 million was needed for JWST in 2009 and another $20 million in 2010 to cover “ongoing cost overruns and inadequate phasing of reserves.”

Mikulski, who chairs the Senate Appropriations commerce, justice, science subcommittee that oversees NASA spending, said the JWST review panel’s findings would be critical to her consideration of NASA’s 2011 budget request.

“I expect that this panel will begin work within the next 30 days and offer recommendations to you and to the Committee in a timely manner,” she wrote.

The 2011 budget request NASA sent to Congress in February for the fiscal year that begins Oct. 1 includes $444.8 million for JWST, or about $60 million more than the agency previously projected needing. That increase comes on top of the $75 million in American Recovery and Reinvestment Act funds NASA added to JWST in 2009 to avert contractor layoffs.

Led by NASA’s Goddard Space Flight Center in Greenbelt, Md., JWST is an infrared telescope with a 6.5-meter foldable mirror and a deployable sunshield the size of a tennis court. An Ariane 5 rocket provided by the European Space Agency is slated to launch JWST to the second Lagrange point — a gravitationally stable spot 1.5 million kilometers from Earth — in June 2014.

The project is currently under construction, with roughly 47 percent of the mass of the observatory in fabrication at prime contractor Northrop Grumman Aerospace Systems in Redondo Beach, Calif., and various subcontractor facilities.

However, while JWST passed its mission critical design review in late April, the program’s Standing Review Board recommended additional component-level verification tests of the spacecraft’s massive sunshield and extended testing of the integrated telescope assembly at the Johnson Space Center in Houston. The review team also advised increasing JWST’s 2011 budget to prevent further schedule erosion.

Jon Morse, astrophysics division director for NASA’s Science Mission Directorate, confirmed that the program is facing both short- and long-term budget challenges. He said projected cost growth associated with the Northrop Grumman-built spacecraft bus alone would wipe out funding margins planned to mitigate unexpected spending needs that could arise in the next two years.

“The cost reserves projected in 2011 and 2012 would be consumed by Northrop Grumman issues themselves, let alone some of the other issues that we also have to deal with at Goddard with the ISIM,” he said in a July 8 interview, referring to JWST’s Integrated Science Instrument Module, the main payload unit that will house the observatory’s four primary instruments.

In addition, Morse said, the extended test regimen recommended by the Standing Review Board could stretch funding reserves in future years, a factor likely contributing to Mikulski’s concern.

“Simply put, NASA must manage the cost and schedule of its large scale programs to the highest standard,” Mikulski wrote in her letter, which outlined four areas for the new independent JWST review panel to assess, including:

  • The technical, managerial and budgetary root causes of cost growth and schedule delays.
  • Current plans to complete development, with particular attention to the integration and testing program and management structure.
  • Changes that could reduce cost and schedule or diminish the risk of future cost increases without compromising the observatory’s performance.
  • The minimum cost to launch JWST, along with the associated launch date and budget profile, including adequate reserves.

Morse told the NASA Advisory Council’s astrophysics subcommittee during a two-day public meeting here July 7-8 that the agency is drafting a response to Mikulski to “make sure whatever additional assessment is done answers the mail, so to speak.” But in addition to ongoing analysis and input from the JWST Standing Review Board, Morse said his division already was in the process of forming a separate team to review cost and schedule needs for the JWST test program.

Morse said the panel, dubbed the Test Assessment Team, was slated to begin work July 9. Led by John Casani, special assistant to the director of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., the team comprises top experts with diverse project experience who Morse said can evaluate the entire JWST test regime, including a planned “end-to-end test” of the telescope’s optical system slated to take place in a giant thermal vacuum chamber at Johnson.

“We’re trying to make sure that this test is just performing all the things that we need to have done, because time is money,” he told the astrophysics subcommittee July 7. “It’s a big deal and we want to make sure that the tests that are being done are the right tests.”

In addition to reviewing JWST test plans, Morse said the Test Assessment Team also is looking to relax some JWST science requirements.

“We are also looking at what science requirements are driving the cost and complexity of the fabrication and test between now and launch,” he said. “I don’t think anything will go away, but the question is, ‘Could we look at relaxation of any of the performance requirements that would make a substantial difference in the cost and schedule to launch?’”

Morse said easing JWST’s science requirements would not entail making hardware-specific changes to the observatory at this stage in the program, but it could mean being willing to accept reduced demonstrated performance on the ground if it means the testing program can be shorter, and less costly. Designing the kind of high-fidelity ground tests needed to prove that JWST’s primary mirror, for example, will deliver exactly its specified performance once in orbit could be prohibitively expensive at this point.

“So now we might look at is there substantial cost savings if the diffraction limit we were able to demonstrate were 2.1 microns, as opposed to 2,” he said. “We just want to know are there some performance requirements that are very difficult and expensive to achieve that if they were relaxed a little bit could make a substantial difference in our program cost and schedule.”

Morse characterized the work of the Standing Review Board and the Test Assessment Team as “complementary” and suggested their combined analysis could satisfy some of the requirements outlined in Mikulski’s letter. He said that in addition to engineers and other experts, both panels boast top scientists among their ranks, including infrared astronomer Michael Werner and astrophysicists Alan Dressler and Matt Mountain.

Morse said the Test Assessment Team is expected to complete its review by the end of August, in time to inform the Standing Review Board’s independent assessment, which he expects to wrap up in September. Internal deliberations and a final plan for the program are anticipated by November, when the agency hashes out its 2012 funding priorities with the White House Office of Management and Budget.