WASHINGTON — The first U.S. government shutdown in 17 years idled over 95 percent of the NASA workforce and threatened the looming launch of a Mars-bound science orbiter until agency officials gave the project special permission to keep working toward its mid-November liftoff. 

“I learned this morning that NASA has analyzed the MAVEN mission relative to the Anti-Deficiency Act and determined that it meets the requirements allowing an emergency exception,” Bruce Jakosky, the University of Colorado, Boulder-based lead scientist for the Mars Atmosphere and Volatile Evolution (MAVEN) mission, informed colleagues Oct. 3.   

Federal agencies were required to furlough all nonessential personnel when Congress failed to enact a routine stopgap spending measure by the Oct. 1 deadline for approving fresh appropriations. Exceptions were made for military personnel, law enforcement officials, air traffic controllers, government meteorologists and other such civil servants deemed essential to protecting national security and preserving life and property. 

“NASA will shut down almost entirely, but Mission Control will remain open to support the astronauts serving on the space station,” President Barack Obama said Sept. 30 from the White House. With Obama and Senate Democrats refusing House GOP demands to change the president’s signature healthcare law in exchange for reopening the government, the shutdown — at press time Oct. 4 — threatened to extend into a second week.

Of NASA’s 18,000 civil servants, only 549 are allowed to work during the shutdown, NASA spokesman Allard Beutel told SpaceNews Sept. 30, the final day of the U.S. government’s 2013 budget year. A further 1,566 NASA civil servants are on call in the event of an emergency, he said. Furloughed employees were told not to use their government-issued phones or email accounts during the shutdown. Most government websites redirected visitors to a message saying, “Due to the lapse in federal government funding, this website is not available.”

NASA Chief Financial Officer Elizabeth Robinson told the White House Office of Management and Budget in a Sept. 27 letter that the agency expected to be able to complete the shutdown of “routine agency activities, which includes the vast majority of NASA employees, contractors, and facilities,” by midday Oct. 1. 

Some NASA activities were exempted from immediate shutdown, such as those in the middle of delicate tests, Beutel said. One such program is the James Webb Space Telescope, an $8.8 billion mission already scrambling to launch in 2018. The observatory’s main instrument module was undergoing cryogenic vacuum testing at NASA’s Goddard Space Flight Center, Greenbelt, Md., when the shutdown took effect. Beutel said the cryo-testing was “being allowed to continue because if you stop it, that has long-term implications.”

However, Matt Mountain, director of the Space Telescope Science Institute, told SpaceNews Oct. 3 that the actual testing of Webb’s Integrated Science Instrument Module has been suspended. The Baltimore institute will run Webb’s science operations.

“What they have done is they have cooled it and they have a crew in place just to keep it cool, but no testing is allowed without Goddard personnel present,” Mountain said. “We are in a suspend mode, but we are cold, which is really important because it takes weeks to warm up and we would blow the schedule” if that was allowed to happen.

NASA suspended MAVEN launch preparations Oct. 1, sparking an outcry from Mars exploration advocates and Sen. Bill Nelson (D-Fla.), who issued a press release Oct. 2 drawing attention to the possibility of the Mars orbiter mission missing its four-week launch window. By the next day, MAVEN was granted an emergency exemption on the grounds that the orbiter must launch this year to protect the rovers NASA already has at Mars. 

“MAVEN is required as a communications relay in order to be assured of continued communications with the Curiosity and Opportunity rovers,” Jakosky told SpaceNews. “The rovers are presently supported by Mars Odyssey launched in 2001 and Mars Reconnaissance Orbiter launched in 2005. Launching MAVEN in 2013 protects the existing assets that are at Mars today.”

Jakosky said spacecraft processing work at Kennedy Space Center, Fla., had resumed and that MAVEN remained on track for a Nov. 18 liftoff from Cape Canaveral Air Force Station aboard a United Launch Alliance Atlas 5 rocket. If MAVEN does not launch by Dec. 15, the orbiter will be grounded until January 2016, when Earth and Mars are once again in favorable alignment.

Delaying MAVEN’s launch some 26 months would add millions of dollars to the mission’s already $670 million price tag.

On top of that, Jakosky said the alignment of Earth and Mars in 2016 would require MAVEN to use more fuel to reach the red planet, potentially cutting into the time available for the craft’s science mission and imperiling its ability to serve as a communications relay for the next six years. Conditions in 2016 would also be poorer for MAVEN’s core science mission of measuring the interaction of solar particles with the upper martian atmosphere, said Jakosky.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.