Apollo 15 — first crewed Lunar Roving Vehicle drive

On the morning of 31 July 1971, Dave Scott and Jim Irwin stood on the Hadley plain with the Apennine mountains towering around them and pulled a series of lanyards on the side of the lunar module Falcon. A folded machine swung down from the descent stage and unfolded itself like a drawbridge: the first car on another world. When Scott took the driver's seat for a checkout spin, the front steering refused to respond. He drove anyway, steering with the rear wheels alone across a landscape no human had ever crossed at speed.

The Lunar Roving Vehicle was an improbable machine built on an impossible schedule. Boeing and General Motors' Delco division delivered it in just 17 months. Each wheel was woven from zinc-coated piano wire with titanium chevrons for tread, driven by its own small electric motor, and the whole vehicle folded flat against the lunar module's hull for the ride out. With no magnetic field to steer by, the crew navigated by a gyroscope-based dead-reckoning system that always knew the way home.

The rover transformed the mission. Scott and Irwin drove 27.9 kilometres in three hours and two minutes of total driving time, reaching the rim of Hadley Rille and the slopes of Mount Hadley Delta, places utterly beyond walking range. At Spur crater they picked up the Genesis Rock, a piece of ancient anorthosite crust roughly four billion years old. Across three moonwalks totalling 18 hours 35 minutes they collected 77 kilograms of samples, more than any previous crew.

The steering mystery resolved itself overnight; the front wheels worked perfectly on the second drive and no one ever fully explained why. Before leaving, Scott performed one last experiment for the television camera, dropping a hammer and a falcon feather together to prove Galileo right in the vacuum of the Moon. Rovers flew again on Apollo 16 and 17, and all three remain parked exactly where their crews left them.