"We must honor their sacrifice by fortifying our commitment to safety and excellence as new generations of space explorers, follow their footsteps."

NASA's Day of Remembrance honored the brave astronauts, test pilots, and crew members of Apollo 1, Challenger, and Columbia who gave their lives exploring the unknown. This tribute serves as a heartfelt reminder of their sacrifice and the critical need for safety in space exploration.

An annual memorial was held at the Kennedy Space Center Visitor Complex. Every fourth Thursday in January, NASA remembers fallen astronauts.

The space agency will honor all its fallen members from the crews of Apollo 1 and space shuttles Challenger and Columbia.

NASA observed its annual Day of Rembrance today honoring those who lost their lives in the pursuit of space exploration.