Astronaut Walter M. "Wally" Schirra Jr., one of the original Mercury Seven astronauts and the only man to fly on all three of NASA's early space missions, has died at the age of 84, a NASA official confirmed Thursday.
Schirra, who commanded the first rendezvous of two spacecraft in orbit, died of natural causes, according to NASA.
"We have spoken with his family and we can confirm he did die of natural causes.