Each year around this time, John Tripp walks across a lunar surface, pondering the challenges ahead for explorers brave enough to take on its cratered terrain. For now, his “moon” is a winding ribbon of cement footpaths looped around Huntsville’s famed U.S. Space and Rocket Center, where Tripp is a construction foreman.

By month’s end, a half-mile of the paths will be transformed into a harsh lunar landscape that will test the engineering savvy and physical endurance of about 400 high school and college students on 68 teams converging here April 4-5 for NASA’s 15th annual Great Moonbuggy Race. The event is organized by NASA’s Marshall Space Flight Center in Huntsville.

The students, hailing from 20 states, Puerto Rico, Canada, India and Germany, are coming to race lightweight moonbuggies they designed, based on the original lunar rovers first used during the Apollo 15 moon mission in 1971. Tripp’s construction team will greet them with 17 unique course obstacles, built of plywood and old tires, and covered with 20 tons of gravel and 5 tons of sand. All of it will be reshaped into moon-like ridges, craters, sandy basins and lava-etched “rilles.”

The course was designed in 1993 by Dr. Larry Taylor, a lunar geologist at the University of Tennessee at Knoxville, Dr. J.M. Wersinger, a physics professor at Auburn University in Auburn, Ala., and Marshall’s University Affairs Officer Dr. Frank Six. It proved so challenging that race planners began adding hay bales for added safety; about 175 bales will line the course this year. Even so, seatbelts are a requirement.

The students appear ready for the challenge. For two days, their vehicles will brave the course against the backdrop of some of America’s most famous rockets and space vehicles. Cheered on by hundreds of friends and spectators, they’ll vie for cash prizes and trophies awarded by NASA and corporate sponsors.

Each moonbuggy starts the competition disassembled and folded for transport — like the actual rovers flown to the moon in the early 1970s. Each buggy must fit into a space no larger than 4 feet in width, height and length. It must be carried in “collapsed” mode to the starting line, assembled, then checked for all required parts — fenders, a flag and simulated hardware, including batteries, a communications antenna, radio and TV camera.

Then, they’re off. Each rover is piloted by two students: one male, one female. The buggies race against the clock instead of each other. Drivers push hard to conquer each obstacle without exceeding the race’s 15-minute time limit — a new rule in 2008.

Tripp keeps the moonbuggy course safe, but tough. As the person in charge of the course for the past 13 years, he’s made a science of getting the right blend of sand and rock, and building the right combinations of steep and shallow features. He has to stay sharp, he said, because student builders grow ever more sophisticated, refining their designs from year to year to field sturdier buggies. The schools also consult with each another. Veterans compare concepts and give new teams free insight.

“That camaraderie is exciting to see,” says Tammy Rowan, manager of Marshall’s Academic Affairs Office, which organizes the race each year. “The race doesn’t just pit schools against one another. It’s a shared experience for students who love math, science and engineering. We hope it shows them the community and partnership that awaits them in these career fields, and provides practical, hands-on experience to reinforce their class work.” Tripp admits he enjoys making the experience a true challenge. His course never fails to keep the pit crews in NASA’s repairs tent busy on race day — welding snapped struts, and replacing bent wheels and sprockets. But most teams push through and Tripp likes that too.

“Some of them reach the end and just fall over exhausted,” Tripp said. “But they get there. That’s what it’s all about.”

The 2008 race is sponsored by NASA’s Space Operations Mission Directorate, along with the Northrop Grumman Corp., The Boeing Company and Teledyne Brown Engineering, all of Huntsville. Additional contributors include the American Institute of Aeronautics and Astronautics; ATK Launch Systems, Inc.; CBS-TV affiliate WHNT (Ch. 19); Jacobs Engineering Science Technical Service Group; Stanley Associates; Science Applications International Corp.; the Tennessee Valley chapter of the System Safety Society Inc.; the United Space Alliance, LLC; and the U.S. Space & Rocket Center.

For more information about the race, visit: http://moonbuggy.msfc.nasa.gov/

For information about other NASA education programs, visit: http://education.nasa.gov/