The second deep-space spacewalk

While Young and Duke were on the surface, Mattingly orbited the Moon 64 times in the Casper module and, as the first command module pilot to do so, used binoculars during his observations. Because of the landing delay, the mission returned a day earlier than planned.

On the way home, Mattingly performed an 83-minute spacewalk to retrieve film cassettes from the exterior of the service module — only the second deep-space EVA in history, more than 300,000 km from the nearest celestial body (after Worden on Apollo 15). Duke assisted him from the command module’s hatch.

The command module splashed down in the Pacific Ocean on 27 April 1972 near Kiritimati island and was recovered by the carrier USS Ticonderoga. Analysis of the returned samples later confirmed that neither the Descartes highlands nor Stone Mountain were volcanic in origin — geologists later admitted they had been too confident in their own theory and insufficiently open to other explanations.