WASHINGTON -- NASA's Mars Science Laboratory will launch two years later than previously planned, in the fall of 2011. The mission will send a next-generation rover with unprecedented research tools to study the early environmental history of Mars.
A launch date of October 2009 no longer is feasible because of testing and hardware challenges that must be addressed to ensure mission success. The window for a 2009 launch ends in late October. The relative positions of Earth and Mars are favorable for flights to Mars only a few weeks every two years. The next launch opportunity after 2009 is in 2011.
Объясняют тем, что в ровере куча моторчиков, и их так и не удалось доделать, довести до ума.
http://www.planetary.org/blog/article/00001761/
They reported that the cruise stage (the spacecraft that will steer the spacecraft from Earth to Mars, handling the navigation and Earth communications along the way) is nearly complete. The descent stage (which will lower MSL to the ground) is basically complete. The rover is mostly built, with five of its instruments delivered, and the rest scheduled for delivery in January. But the fact that the actuators have not yet been delivered is a big, big, big problem. McCuistion said that the rover is designed to contain a total of 31 of these actuators in a variety of sizes. That means they need to build 60 flight-qualified units (basically, two of each; after testing, the best one will be placed into the rover), and then there will be 45 provided as engineering models, which are used for life-cycle testing and for mission operations, when they will need to troubleshoot any problems they encounter on Mars with duplicate copies of the actuators on Earth.
There are great big ones that will drive and brake the wheels and rotate them on the ends of the legs. There are good-sized ones in the robotic arm, in shoulder, elbow, and wrist joints. And there are numerous small ones within the mechanisms designed to collect and deliver samples to the package of analysis instruments within the belly of the rover. Not a single flight actuator has yet been delivered to JPL; they keep encountering problems. McCuistion said they've encountered "workmanship problems," mentioning bearings not being installed exactly correctly, and problems with devices within the actuators that are designed to measure how much they've moved.
Until they work out these problems, they can't even begin life cycle testing, where they take engineering models of the actuators and run them and run them and run them, simulating two years' worth of operations on Mars, to see if the motors really can last throughout the planned mission.