Apollo 1 was the first crewed mission of NASA's Apollo program, intended to land humans on the Moon. The mission was originally designated AS-204 and was scheduled for launch on February 21, 1967. Tragically, a cabin fire during a pre-launch test on January 27, 1967, claimed the lives of all three astronauts: Virgil "Gus" Grissom, Edward H. White II, and Roger B. Chaffee. The fire was fueled by the high-pressure pure oxygen environment inside the spacecraft. This disaster led to significant design and safety changes in the Apollo spacecraft, ultimately improving the safety of future missions. Apollo 1 is remembered as a pivotal moment in space exploration history.