Original URL: http://www.theregister.co.uk/2010/03/08/curiosity_passes_actuator_test/

'Curiosity' nuclear Mars tank passes key tech test

Good to go for 2011 - 'knock wood', says NASA bigwig

By Lewis Page

Posted in Science, 8th March 2010 12:43 GMT

NASA bigwigs say that their nuclear powered, laser-packing robotic tank, intended to prowl the ochre plains of Mars, has had its most troublesome bugs ironed out and will be ready to blast off for the red planet next year.

The Mars Science Laboratory - aka "Curiosity" - is a hefty small-truck-sized rover, significantly bigger than the current Spirit and Opportunity solar-powered jobs, one of which is still roving and the other now permanently bogged in the reddish sands of the fourth planet.

MSL/Curiosity had originally been meant to set off for Mars last year, but technical delays with the sophisticated machine have pushed the departure date back - and caused its cost to balloon from $1.6bn to $2.3bn.

The worst of these technical snags has been with the rover's actuators, which drive its wheels and operate its robotic arm and other moving hardware. Aviation Week reports that these have now passed their two-times design life tests, a requirement set by NASA boffins at the Jet Propulsion Laboratory in California.

"The final actuator that we were having problems with has passed its two-times life test," NASA bigwig Ed Weiler tells Av Week. "Knock wood — the actuator problem on MSL, which has been the biggest problem, seems to be behind us."

Weiler is proud of the JPL's rigorous approach to design and testing, commenting on the two-times-life requirement:

“That’s the way JPL does business. Maybe it’s an explanation of why we launch 90-day rovers that last six years."

Spirit and Opportunity were only intended to work for 3 months following their landings in 2004, but remain operational to this day.

Curiosity still has some bugs left to be sorted out. Its radioisotope power battery - the rover won't carry a full-blown reactor - is showing signs that it may run down more quickly than expected, but this isn't expected to be a big deal. It will merely mean that the machine will have to spend more time charging up batteries (it is actually nuclear-hybrid rather than purely nuclear powered) and/or less time rolling in the later stages of its mission.

NASA now expects to fire Curiosity off to Mars in September 2011. ®