JWST. Credit: Northrop Grumman

WASHINGTON — NASA officials told a gathering of astronomers in Long Beach, Calif., that the James Webb Space Telescope (JWST), which is entering one of the most technically challenging parts of its long development cycle, would likely fare well even in a worst-case budget scenario that could suck $1.5 billion off NASA’s $17.8 billion top line.

JWST is expected to launch in October 2018 and cost $8.8 billion to build, launch and operate for five years. The project has been accorded high priority by both the White House and Congress, which otherwise remain at loggerheads over federal spending.

NASA, like the rest of the federal government, is still being funded under a six-month continuing resolution that holds spending to 2012 levels. NASA Astrophysics Division Director Paul Hertz said in November that the temporary spending measure, which is expiring March 28, provides all the funding JWST needs in 2013.

For the 2014 fiscal year that begins Oct. 1, the picture is murkier.

Congress and the White House still have to resolve a host of broader budget issues, including averting unpopular automatic across-the-board spending cuts whose phase-in was postponed two months to March 1 by legislation President Barack Obama signed Jan. 3. If the sequester is allowed to occur, NASA stands to lose about 8.2 percent, or $1.5 billion, of its $17.8 billion budget.

But Hertz and his boss, NASA Associate Administrator for Science John Grunsfield, told astronomers in Long Beach that JWST likely would be spared from those cuts — meaning that other NASA programs, some of which are already paying for JWST’s cost growth, might have to contribute even more if the cuts do happen.

Hertz said at a Jan. 8 town hall during the American Astronomical Society’s winter meeting in Long Beach that he believed that JWST’s priority status means the project “will not participate in the budget reduction” that would happen should the White House and Congress fail to avert sequestration.

Eric Smith, JWST deputy program director, made the same point the next day at another American Astronomical Society town hall meeting.

“Folks at NASA headquarters have recognized JWST as the top science priority for the agency,” Smith said Jan. 9. “It is fully supported at all levels of NASA from the administrator on down. It is the top thing we’re working on.”

Congress and the White House have given themselves until the end of February to deal with sequestration. Several government sources in Washington the week of Jan. 7 said they expected the White House and Congress to address the cuts as part of a broad deal that also raises the U.S. debt ceiling and sets federal spending levels for the remainder of this fiscal year.

Meanwhile, various JWST science instruments are on the verge of being integrated with one another and tested together in space-like environments for the first time.

“This year, it’s instrument integration,” Smith said during the webcast  town hall meeting. “[Integration and testing] will be hard for a project of this size.”

A big milestone is approaching this summer, Randy Kimble, JWST integration and test project scientist at the Goddard Space Flight Center in Greenbelt, Md., said during the meeting.

Around June or July, four critical JWST instruments — the Near Infrared Spectrograph, the Near Infrared Camera, the Mid-Infrared Instrument and the Fine Guidance Sensor/Near Infrared Imager and Slitless Spectrograph — will be integrated into JWST’s Integrated Science Instrument Module and begin cryogenic environmental testing.

The Near Infrared Spectrograph and Near Infrared Camera had not yet arrived at Goddard but were undergoing separate cryogenic tests as of Jan. 8, according to slides Hertz presented at Long Beach. The other two instruments have been placed in the Integrated Science Instrument Module at Goddard, where they are set to undergo cryogenic testing together in March or April, according to a chart Kimble presented.

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...