The much-beleaguered Mars Science Laboratory -- an ambitious and expensive rover/lander whose main purpose is to assess whether Mars can or ever could have supported microbial life -- will be delayed by two years. It was set to launch in the fall of 2009, but it will be 2011 at least before it goes to Mars.
The MSL has been a source of a lot of woe. It has been plagued with cost overruns, timeline slips, and technical difficulties. That last bit is not surprising; the technology on this mission is extremely sophisticated and some of it is cutting-edge. Technical problems lead to both timeline problems as well as cost overruns, so these are all related. Also, the rover is huge: it's the size of a golf cart (for comparison, the rovers Spirit and opportunity are about the size of a kid's red wagon), meaning landing it is extremely tricky. Charles Elachi, director of NASA’s Jet Propulsion Laboratory, likened it to a Cassini-class mission, and it has to actually land on another planet. The mission lifetime is supposed to be two years (compare that to the nominal 90 day planned lifetime for the current rovers), and the chemistry lab it carries to test the Martian environment is very sophisticated.
The lifetime cost of MSL is a little under $2 billion. This delay will add roughly $400 million to the lifetime cost, bringing the cost to about $2.2 - 2.3 billion. This will hurt other missions, of course, since NASA has a finite budget. Money will have to be shuffled, but "no cancellations are expected" (the cuts across the board will have to be spread over the next couple of years). This money will go to storing the mission hardware and further testing of all the equipment.
To be fair, most of the hardware is well on its way to being complete. Mike Griffin, NASA Administrator (aka the Big Cheese) stated that the main problem causing the delay is a problem in the rover's actuator motors. NASA might be able to meet the initial launch date, but they want to be sure that such a big and expensive mission will operate as flawlessly as possible. There were quite a few technical difficulties that weren't life-threatening, but still caused many delays.
The delays aren't too bad in and of themselves, but the Universe forces the much longer delay. Mars and Earth both orbit the Sun, and the favorable launch positions of the two planets only occur roughly every 26 months. Each launch window lasts a few weeks, but if that's missed, it takes two years before the next window opens. That's why MSL won't launch until 2011.
Griffin said that this mission is second only to manned missions, so they're taking it very seriously. It's too bad this has happened, and I hope the impact on other missions won't make them feel the hurt too badly.
Sometimes I like to compare things like this to Hubble: it was over budget, took too long, and when it launched it had a terrible flaw that severely limited its usefulness... and now, no one talks about any of that at all, we talk more about the impact Hubble has had on the public's awareness of astronomy (in positive terms). I suspect in a decade we'll be saying the same sort of things about MSL. That doesn't diminish the impact or the trouble NASA is feeling from MSL's problems, but it's sometimes good to keep these things in perspective.
Image courtesy NASA/JPL.