NASA will postpone the launch of its over-budget Mars Science Laboratory (MSL) rover by two years, to 2011. The delay will add another $400 million to the cost of the mission and will probably force the delay of other agency missions, officials say.
The SUV-sized, nuclear-powered rover, which aims to test whether the planet is or once was capable of supporting life, was originally set to launch in October 2009.
But lingering technical problems will push lift-off until the next Mars launch window in late 2011.
The rover will be delayed to address a "backlog of unresolved work" and undiagnosed problems with the rover's actuators, motor-driven gears that move the spacecraft's wheels, bend its robotic arm, and drive its drill, NASA administrator Mike Griffin told reporters.
Fixing such issues might only take a few months, and with additional funding, the agency might have rushed to attempt a 2009 launch.
"But we've determined that trying for '09 would require us to assume too much risk - more than I think is appropriate for a flagship mission like Mars Science Laboratory," Griffin said.
The added delay will bring the total lifetime cost of the rover mission to more than $2.2 billion. MSL is already $300 million over its proposed 2006 budget of $1.6 billion.
Former NASA science chief Alan Stern criticised such overspends in a recent editorial in the New York Times, arguing that they sharply limit the number and capability of missions the agency can undertake.
But Griffin said the growth in cost is a natural part of ambitious projects with unforeseen difficulties. "We know how to control cost - just build more of what you built the last time," Griffin said.
Citing the Hubble Space Telescope and the COBE satellite, which cost more than twice as much as their original budgets, Griffin added that "some of the things NASA has done of which we in the nation and indeed the world are most proud are things where we had far more troubles than we're having on Mars Science Lab."