アポロ司令・機械船
In April 1966, McDivitt, along with Astronaut Group 3 astronauts David Scott and Rusty Schweickart were named as members of the backup crew for Gus Grissom's first crewed Apollo mission Apollo 1, flying only the Apollo Command/Service Module in Earth orbit. In December, they were replaced as backups with Wally Schirra, Donn Eisele, and Walt Cunningham, the crew of the original second mission which was cancelled, and were promoted to prime crew of a new second mission flying both the Command/Service Module and the Apollo Lunar Module. They were training for this mission when tragedy struck on January 27, 1967: A cabin fire killed Grissom's crew and brought a 22-month suspension of crewed Apollo flights.