10 September 2004

The rovers are still touring Mars

Forrest M. Mims III

The crash of NASA's Genesis space capsule into a Utah desert the morning of 8 September 2004 was in sharp contrast with the remarkable success of the two rovers still exploring the surface of Mars.

Last January NASA landed two self-propelled robots on the sand and rock-covered surface of Mars. The robots are named Spirit and Opportunity. Both are packed with TV cameras and instruments.

Spirit and Opportunity were supposed to have a life of around three months. Yet both rovers are still operating today, after more than two times their planned life.

It's winter on Mars. The solar panels that provide electrical power to the two rovers are receiving less sunlight than during the Martian summer.

The electrical power from the solar panels is also reduced somewhat by dust that has accumulated on them. There is actually a good deal less dust than there might have been had the rovers experienced one of the dust storms for which Mars is famous.

The reduced electrical power has meant that the rovers have had to rest more than before. The tough terrain of Mars has also taken its toll.

Wheels have spun and slipped in loose sand. A pebble jammed a drilling tool for a while. Mysterious electronic quirks have come and gone. Wires leading to one of the movable cameras might be about to break.

Still, the scientists at NASA's Jet Propulsion Laboratory continue to carefully guide Spirit and Opportunity around rocks and across sandy speed bumps.

Currently, Spirit is climbing up into what has been named the Columbia Hills. As it rolls slowly along, its cameras are providing views of a distant, lava covered landscape.

Meanwhile, halfway around Mars, Opportunity is slip-sliding its way around the bottom of a crater named Endurance. On its way down into the crater, its cameras peered at, and its instruments measured, increasingly older layers of rock.

Opportunity has returned crisp photographs of miniature sand dunes strewn along the bottom of Endurance Crater. The question now is will the tough robot be able to spin its wheels enough to climb back up to the desolate plain above?

The Mars rovers have done much to stimulate an interest in robotics by high school students. Based on my daughter Sarah's experience leading a robotics team during her senior year in high school, students can learn more from a robotics project than by sitting in a classroom.

It's not quite the same as guiding robots across Mars. But it's great training for the next generation of space scientists.

Forrest M. Mims III and his science are featured online at http://www.forrestmims.org/.

This feature was originally published in Forrest Mims's weekly science column in the Seguin Gazette-Enterprise, Seguin, Texas. The column is written for a general audience.