Moon Rovers
Dave Scott Reflected in Jim Irwin's Visor
Astronaut Jim Irwin is doing just what tourists do the world around, taking snapshots of the wonderful and exotic places he is visiting. In this photograph, he is immortalizing his partner, Apollo 15 crew commander Dave Scott, proudly riding in their new car, the lunar rover.
This is not just any car. This car is special, a genuine first edition, the first car on the Moon. Because there is no atmosphere up here, it cannot use a gasoline engine. Two large batteries power four small one-quarter horsepower electric motors, each about the size of a handyman's electric drill, one driving each wheel. Looking like a stripped down dune buggy, it weighs 462 pounds on Earth but only 77 Moon pounds. In fact, Jim and Dave will occasionally just lift it up and turn it around rather than drive in reverse. There is no way they can turn around in their stiff space suits to see where they would be going. The rover can reach speeds of about 6 miles per hour on level ground with battery power for more than 60 miles of driving. The tires are of woven piano wire. The TV camera and umbrella-like antenna beam pictures of their activities back to Earth.
Later today, Jim and Dave will take a two-hour drive to the brink of a canyon and to the dusty base of a moon mountain. Jim will say: "The ride is bouncy and rolling, a combination of a bucking bronco and a rowboat in a rough sea." Dave will remember, "It's a sporty job to drive and not to run into craters." They will cover 6 miles on this first of three drives - much more than the 3 miles covered by all of us who came before. We were moon rovers, too; but only pedestrians.