Without funding to pay for numerous programs and research, engineers began shutting down work on a $671 million Mars science orbiter at the Kennedy Space Center on Tuesday, halting critical preparations ahead of the mission's narrow interplanetary launch window in November.

MAVEN principal investigator Bruce Jakosky, backdropped by the MAVEN spacecraft, speaks with reporters Friday inside the Payload Hazardous Servicing Facility at the Kennedy Space Center in Florida. Credit: Stephen Clark/Spaceflight Now
 
The launch window, which opens Nov. 18 and extends to Dec. 7, is restricted by the locations of Earth and Mars. Launch opportunities to the red planet only come once every 26 months.

The Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft was on schedule to launch from Florida on Nov. 18 aboard a United Launch Alliance Atlas 5 rocket. The launch will put MAVEN on a 10-month journey to Mars, with arrival in orbit at the red planet set for Sept. 22, 2014.

But the launch date could be in jeopardy if the federal government's partial shutdown lasts more than a week. The shutdown began at midnight EDT Tuesday, at the beginning of a new fiscal year, because Congress failed to agree on a federal budget.

NASA will continue operating missions in flight, such as the International Space Station, the Hubble Space Telescope and the Curiosity rover now on Mars, but the space agency, acting on orders from the Office of Management and Budget, halted development and testing of spacecraft still on Earth awaiting launch.

"MAVEN has not been classed as exempt from the shutdown, so our plan is to carry out an orderly shutdown," said Bruce Jakosky, MAVEN's principal investigator from the University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics.

NASA and Lockheed Martin Corp., MAVEN's prime contractor, were preparing the spacecraft inside a clean room at NASA's Kennedy Space Center in Florida.

MAVEN carries a suite of instruments to study how gases escape from the upper atmosphere of Mars, which could tell scientists how the red planet evolved from a world hospitable for life to the barren planet of today.

"In an orderly shut down, the key thing is to ensure that all the hardware is in a safe and known state so that we can pick it up again when we resume, and that it is protected against environmental problems," Jakosky said.

Uneasy with MAVEN's launch schedule following the government shutdown, officials said they are evaluating whether this fall's launch window could be extended a few days into mid-December to buy more time.

If MAVEN missed this year's launch window, the next chance to launch the probe toward Mars would be in early 2016.

Artist's concept of the MAVEN spacecraft at Mars. Credit: NASA/GSFC
 
Engineers made good progress on MAVEN since the orbiter arrived at KSC from its factory in Denver on Aug. 2, said Guy Beutelschies, Lockheed Martin's MAVEN program manager, in an interview Friday.

Beutelschies said the MAVEN team was working with nine days of schedule margin to meet the Nov. 18 launch date.

Technicians ensured all of MAVEN's systems still functioned after the cross-country flight from Denver, installed the satellite's flight batteries, put the spacecraft through mission simulations, tested its communications with NASA's network of tracking antennas, and unfurled its solar panels to check their deployment mechanisms, according to Beutelschies.

The next steps were to finish up testing of MAVEN's propulsion system and put the cubical spacecraft on a spin table to check its mass properties.

MAVEN's load of toxic hydrazine propellant was scheduled to be pumped into the orbiter's propellant tank in late October, and Lockheed Martin was planning to hand over the spacecraft to United Launch Alliance on Nov. 1 for attachment to the Atlas 5 rocket's payload adapter and encapsulation inside the launcher's four-meter-diameter payload fairing.

"The team, absolutely across the board, institutions and individuals alike, is totally committed to doing whatever it takes to launch on time," Jakosky said Monday. "We're prepared to schedule double shifts and work seven days if necessary, ensuring, of course, that we do things safely and technically correctly. We'll have to wait and see what the feds do over the next one to several days."