Apollo 16

Apollo 16 was the fifth NASA mission to land astronauts on the Moon, touching down in the Descartes Highlands on 21 April 1972. Commander John Young and Lunar Module Pilot Charles Duke spent 71 hours on the surface across three EVAs, collecting 95.8 kg of lunar samples while Ken Mattingly orbited in the Command Module. The mission targeted the lunar highlands specifically to test the theory that the Descartes region was volcanic in origin; the samples proved it was impact-formed instead, overturning pre-mission geological models.

Apollo 16 is relevant to Artemis II because the mission encountered the largest solar particle event of the Apollo era. Had the crew been on an EVA during the event rather than inside the spacecraft, radiation exposure would have been life-threatening. The incident became a foundational case study for NASA radiation planning and directly informed the Space Radiation Analysis Group (SRAG) protocols now protecting Artemis crews.

The 1972 solar storm remains the benchmark against which modern Space weather risk is measured. Artemis II flies with significantly better forecasting (GOES-19 coronagraph data, SRAG real-time monitoring) but also ventures further from Earth than any Apollo crew, extending exposure time beyond the Apollo envelope.