NASA tests Mars rovers in California desert

by Texas A&M University. Contact: Judith White jw@univrel.tamu.edu

COLLEGE STATION, August 23, 2002 – For an elite group of scientists, "space camp" this summer meant simulating what will happen when NASA sets two robotic research vehicles on the surface of Mars early in 2004.

With less than a year to go before the launch of NASA's Mars Exploration Rover mission, researchers have spent the last few weeks doing high-tech simulations, rehearsing their roles for when the spacecraft take center stage. Among them is Texas A&M University atmospheric physicist Mark Lemmon.

Although Lemmon won't personally be visiting the Red Planet, his experiment will be part of the mission, consisting of two identical robotic rovers scheduled for launch in mid-2003, to arrive at separate destinations on Mars in early 2004. Part of the rovers' mission will be to get a better handle on the nature and accumulation and dissipation patterns of Mars' signature red dust.

"One my goals for the Mars Exploration Rover mission is to figure out what's in the atmosphere of Mars in order to give us better insight as to what the global climate was like in the past and what it could be like in the future," said Lemmon, a research scientist in the Department of Atmospheric Science of the College of Geosciences.

According to most scientists who study Mars, dust is a defining feature of the planet's atmosphere and may constitute the major force eroding the planet's surface, much like the role played by water on the Earth. Understanding the dust on Mars today is vital to understanding how to prepare for the safety of future astronauts who travel to the red planet.

"We think the dust on Mars is composed mainly of clay missed with iron and magnetic material," explained Lemmon. "If humans travel to Mars in the future, they will have to fight the dust to survive."

To test the rovers under simulated Martian conditions, the team at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., sent one of the robots out to a distant, undisclosed desert location, while the JPL team planned operations and remotely sent commands, just as they will do when the actual rovers land on Mars. The Mars Exploration Rover mission is managed by JPL, a division of the California Institute of Technology , for NASA's Office of Space Science, Washington, D.C.

"The scientific instruments on this test rover are similar to the Athena science payload that will be carried by the Mars Exploration Rovers," said Steve Squyres, principal investigator for the Mars Exploration Rover mission at Cornell University, Ithaca, N.Y. "We're using the test rover now to learn how to do good field geology with a robot. When we get to real Mars rover operations in 2004, we'll be able to use everything we're learning now to maximize our science return."

The 10-day blind test, which ran from Aug. 10 to 19, used the Field Integrated Design Operations testbed, called FIDO, which is similar in size and capability to the Mars Exploration Rovers. Although important differences exist, the similarities are great enough that the same types of challenges exist in commanding these rovers in complex realistic terrain as are expected for the rovers on Mars.

The test rovers received and executed daily commands via satellite communications between JPL and the remote desert field site. Each day, they sent images and science data to JPL, revealing properties of the desert geology, and the tests have been rated a success. The real rovers are currently being built at JPL and will be shipped to the Kennedy Space Center in Florida early next year to begin preparations for launch. Shortly before the launch, NASA will select the landing sites.

In addition to his participation in the FIDO field trials, Lemmon also went to Hawaii to discover first-hand the difficulty of dealing with Mars-like dust.

"We hiked around Kauai in the volcanic areas where the dust is similar to martian dust, and by the time we got back to our rental car, the entire car, inside and out, was coated with red dust," Lemmon observed. "I got home from my trip, and my socks are still red after washing them at least 30 times."

Lemmon, who while at the University of Arizona was also on the Mars Pathfinder imaging team in 1997 and the 1999 Mars Polar Lander science team, is hoping to facilitate scheduling of images such as night-time pictures of Mars' moons, Phobos and Deimos, including photos of formation of morning fogs on Mars and shots of Phobos eclipsing the sun. "The most active process occurring on Mars is the movement of dust in the atmosphere, so my project will focus on dust obscuring the sun during our real mission," Lemmon said.