On the Moon with Apollo 16

Apollo 16 landed in the Descartes Highlands of the Moon on April 21, 1972. John Young and Charlie Duke spent three days exploring the craters and mountains around their landing site.

This was another landing that almost didn't happen. After the Lunar Module Orion separated from the Command Module Casper, Ken Mattingly had difficulty with the backup system for steering the Service Module's main engine. This could have affected the crew's ability to return to Earth. The landing was delayed, and Orion and Casper flew in formation for 6 hours, until Mission Control assured the crew that everything was ok.

One of the most uncomfortable situations for the crew resulted from potassium supplements which had been added to their food and orange juice. Flight surgeons believed that the heart problems experienced by Apollo 15 moonwalkers Dave Scott and Jim Irwin were attributable to loss of potassium, so they added large doses of the mineral and citrus fruit to the Apollo 16 crew's diet. The potassium acted as a laxative, and the crew nearly depleted their supply of fecal bags. John Young was infamously and unknowlingly captured on his open mic talking to Charlie Duke about his reaction to the potassium: "I got the farts again, Charlie...I mean, I haven't eaten this much citrus fruit in 20 years! And I'll tell you one thing, in another 12 f*cking days, I ain't never eating any more."