The crew of the first Apollo mission, from left, Edward H. White II, Virgil "Gus" Grissom, and Roger B. Chaffee, pose in April 1966.
All three men were killed on Jan. 27, 1967, when a fire erupted inside the Apollo command module during a preflight rehearsal test.
Mechanics work on the Apollo 1 command module during preparation for installation of the crew compartment heat shield.
The Apollo 1 mission was supposed to be the first of several crewed flights NASA conducted to prepare for its first moon landing. But the spacecraft never made it off the launchpad, and it was destroyed nearly a month before its planned launch date, Feb. 21, 1967.
From left, Gus Grissom, Edward White, and Roger Chaffee pose during training in Florida in January 1967.
Gus Grissom tests his spacesuit ahead of the mission.
Apollo 1 crew members practice water egress procedures in a swimming pool at Ellington Air Force Base in Houston, Texas. Edward White rides on the life raft in the foreground. Roger Chaffee sits in the hatch of the boilerplate model of the spacecraft. Gus Grissom waits inside the spacecraft.
From left, Roger Chaffee, Edward, White and Gus Grissom sit inside a practice module at Cape Kennedy, Florida.
An investigator looks at the charred interior of the Apollo I command module after the flash fire that killed the astronauts.
NASA's ground crew tried desperately to rescue the astronauts, but they died of asphyxiation before rescuers were able to get them out of the spacecraft.
Technicians and officials inspect the aluminum-covered Apollo 1 spacecraft after it was lowered from its booster at Cape Kennedy on Feb. 17, 1967.
An officer stands guard at the at the Saturn 1 launch pad area on Jan. 28, 1967, the day after the fire.
Astronaut Virgil "Gus" Grissom is buried at Arlington National Cemetery on Jan. 31, 1967.
For its official "Day of Remembrance" on Tuesday, Jan. 31, NASA will hold an observance and wreath-laying ceremony at Arlington National Cemetery by the graves of astronauts Gus Grissom and Roger Chaffee.