David Scott and James Irwin unfolded a four-wheeled, battery-powered vehicle on the plain of Hadley Rille. The Lunar Roving Vehicle weighed 460 pounds on Earth but only 77 pounds on the lunar surface. Its wire-mesh wheels, designed by General Motors and Boeing, left parallel tracks in the dust that would remain undisturbed for millennia. For the next three days, the rover extended the astronauts' range from a few hundred meters to over 17 miles of traverses. They collected 170 pounds of rock and soil, including the Genesis Rock, a piece of the moon's primordial crust.
The mission was the first of NASA's "J" series, focused on prolonged scientific exploration. Previous Apollo crews had hopped about on foot, their movements constrained by bulky suits and limited oxygen. The rover was a logistical multiplier. It carried tools, cameras, and samples. It let Scott and Irwin travel to the base of the Apennine Mountain front, a task impossible on foot. The vehicle's television camera, operated by mission control, provided the public with a driver's-eye view of stark landscapes.
A common assumption is that the rover was about speed. Its top velocity was a modest 8 miles per hour. The true innovation was endurance and load-bearing capacity. It turned geologists in pressurized suits into effective field scientists. The rover's success on Apollo 15 guaranteed its use on the final two lunar missions, vastly increasing their scientific yield.
The three rovers left behind are monuments to practical engineering in an extreme environment. Their aluminum frames and polyester seats are frozen in vacuum, parked where their drivers last used them. The tracks near Hadley Rille, visible in orbital images, are the first ghost roads of a world without air or life.