Thomas Kenneth "Ken" Mattingly II, (born March 17, 1936) is a retired American astronaut and rear admiral in the United States Navy who flew on the Apollo 16, STS-4 and STS-51-C missions. He had been scheduled to fly on Apollo 13, but was held back due to concerns about a potential illness (which he did not contract). He later flew as Command Module Pilot for Apollo 16, making him one of only 24 people to have flown to the Moon. Read more