Mattingly’s second chance

Command module pilot Ken Mattingly had originally been slated to fly on Apollo 13 — three days before launch he was replaced by backup Jack Swigert after exposure to rubella (caught from a colleague’s child, Charles Duke’s son). Mattingly never got sick, and two years later got a second chance on Apollo 16 — this time alongside Duke himself.

Apollo 16 launched on 16 April 1972 at 17:54 UTC from Pad 39A — the second “J mission” of the Apollo program, with an extended lunar stay and a rover aboard. It was commanded by John Young, a veteran of four previous flights (Gemini 3, Gemini 10, Apollo 10), for whom it was a record-tying fourth trip to space.

The crew named the command module Casper (after the cartoon character Casper the Friendly Ghost) and the lunar module Orion (after the constellation). On the second day of the flight Mattingly reported “gimbal lock” — a loss of orientation in the guidance platform, which he had to manually realign using the Sun and Moon.