FETCH, FIDO, FETCH; STUDENTS HELP TEST MARS ROVER FROM AFAR.

Byline: Andrew Bridges

Here on a rocky desert plain similar to the hostile surface of Mars, the Jet Propulsion Laboratory on Thursday wound up a two-week field test of a prototype of twin rovers it will send to the Red Planet in 2003 and again in 2005, a semi-autonomous vehicle even a high school student can drive.

In fact, a group of high school students joined the group of JPL scientists and engineers for the last several days of testing. The students, gathered at the test site and at high schools in Los Angeles, Phoenix, St. Louis and Ithaca, N.Y., took turns remotely controlling the 154-pound rover, dispatching it to investigate Mars-like rocks lying in the Mojave Desert scrubland roughly 100 miles west of Las Vegas.

``Just imagine it on the surface of Mars,'' said Emily Dean, 16, one of a handful of students chosen to visit the test site, as the rover set out to explore an alluvial wash peppered with rocks.

JPL began work on the Field Integrated Design and Operations rover just over a year ago. The tests concluded Thursday were the first field trials of the rover conducted outside the giant sandbox known as the Mars Yard on JPL's La Canada Flintridge campus.

``It's been performing quite well, if I don't say so myself,'' said Mike Garrett, a JPL engineer who helped build most of FIDO's hardware components.

The rover is designed to collect soil and rock samples that will be returned to the lander craft, which will then launch them into Martian orbit where they will be collected by a French-built spacecraft and returned to Earth for study, possibly as early as 2008. When they parachute down in the Utah desert, it will mark the first time extraterrestrial samples have been robotically returned to Earth.

The rover is roughly twice the size of the Sojourner rover JPL landed on Mars in 1997. That allows it to be more laden with instruments to study the equatorial region where scientists hope it will safely set down.

During its first 90 days on Mars, the rover will stick close to the lander, gathering samples, included core samples it will drill from solid rock, as quickly and efficiently as possible. After the Mars Ascent Vehicle blasts off with the samples, however, the rover will spend 90 more days traveling farther afield, venturing as far as one half-mile from its starting point as it continues to explore Martian topography and geology.

``It will be its own field geologist,'' said Ray Arvidson, a professor at Washington University in St. Louis and the deputy principal investigator on the mission's science team.

The main focus of the twin missions, which have a total price tag of $1.2 billion, is to study the chemistry and geology of Mars, including any evidence of a planet that was once warmer and wetter - and thus may have harbored life.

``The smoking-gun evidence is in the rock record,'' Arvidson said.

CAPTION(S):

photo

PHOTO JPL instructor Steven Dworetzky guides Thomas Starr Middle School students in operating an experimental Mars rover via computer.

John Lazar/Daily News