The U.S. government shut down on Oct 1st, sending approximately 97% of NASA's total workforce home without pay, leaving only a skeleton crew to support the astronauts on the International Space Station.

NASA's shutdown guidelines [pdf] state that "if a space launch has not commenced or is not in flight, preparation activities will generally cease, except to maintain powered systems to monitor and maintain the safety of the assets."

If that sounds a little vague, it is. But it's really hard to know what the impact to MAVEN's schedule will be. It's an understandably fluid situation, and the full impact of a shutdown – if it even happens at all – won't be known until after the government resumes its business. Even Lockheed-Martin, the prime contractor building MAVEN, doesn't know what will happen yet.

The worse-case scenario is that MAVEN misses its launch opportunity to Mars. These only come around every 26 months and remain open for only a short time. MAVEN's has only 20 days between November 18th and December 7th. If MAVEN cannot launch in time, it will have to wait for the next opportunity in early 2016, a delay that would cost NASA's Planetary Science Division tens of millions of dollars it cannot afford.