NASA’s Mars Science Laboratory (MSL) has successfully completed a set of rigorous actuator tests, which agency managers hope is a sign that the problem-plagued rover mission has finally turned a corner.

“The great news last weekend is that the final actuator that we were having problems with has passed its two-times life test,” Associate Administrator for Science Ed Weiler said during a Space Foundation breakfast in Washington March 4. “So — knock wood — the actuator problem on MSL, which has been the biggest problem, seems to be behind us.”

MSL’s actuators will drive the rover’s wheels and its robotic arm. The two-times life tests, conducted at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., run the actuators continuously for twice their design life. “That’s the way JPL does business. Maybe it’s an explanation of why we launch 90-day rovers that last six years,” Weiler said, referring to the agency’s highly successful Mars Exploration Rovers.

MSL is still grappling with other technical issues, but they are not potential showstoppers on the level of the actuator problems, Weiler said. The radioisotope thermoelectric generator (RTG) that will power the rover is showing faster-than-expected power degradation, but Weiler said this is likely only to have a small operational effect in the later parts of the mission, when it might dictate more battery charging time or somewhat less roving. Other areas of lingering concern include the rover’s sand pump, which is being built at Goddard Space Flight Center, and radar module, but these are fairly typical problems for missions at this stage of development, Weiler said.

MSL is an ambitious rover the size of a small car intended to study the Martian climate and geology while searching for signs of past or present life. Development problems caused the mission to miss its original 2009 Mars launch opportunity and refocus on a September 2011 launch (Aerospace DAILY, Dec. 5, 2008). The slip and various technical problems have caused the program’s total cost to grow from an original baseline of $1.64 billion up to $2.3 billion — a $660 million increase — according to a recent assessment from the U.S. Government Accountability Office. This has eaten significantly into the budget for other NASA Mars projects.

Artist's concept of Mars Science Lab Rover: NASA