This plaque is a replica of the one left on the Moon by the crew of Apollo 16, who landed on the lunar surface on April 20, 1972. While command module pilot Ken Mattingly orbited the Moon, astronauts John Young and Charlie Duke landed at Descartes, performing EVAs that included driving the Lunar Roving Vehicle and deploying experiments. Because the design of the lunar module (LM) left the base of the spacecraft on the Moon after the upper stage launched back to rendezvous with the command module (CM), the plaque attached to a leg of the LM became a permanent marker on the lunar surface. Because Apollo 13 did not land on the Moon, the base of the Apollo 16's LM "Orion" became the fifth such marker on the lunar surface.
NASA transferred this plaque to the Museum in 1975.