CAPE CANAVERAL, Fla. — NASA's space shuttle Challenger launched from the Kennedy Space Center at Cape Canaveral on its 10th mission on Jan. 28, 1986.
It exploded 73 seconds after liftoff, claiming the lives of all seven people onboard: Gregory Jarvis, Judith Resnik, Dick Scobee, Ronald McNair, Mike Smith, Ellison Onizuka and Christa McAuliffe.
NASA remembered the fallen Challenger astronauts, as well as the crews of Apollo 1 and the space shuttle Columbia, in its Day of Remembrance ceremony Thursday. More than 100 people gathered at the Kennedy Space Center to remember astronauts killed in the line of duty, and other ceremonies were held at NASA centers around the country.
The NASA remembrance ceremony began in 2004 and pays homage to three of the agency's most devastating tragedies: the Apollo I fire, the loss of the space shuttle Challenger and the loss of the space shuttle Columbia.
Because of the clustering of the three dates, NASA sets aside the last Thursday of every January to commemorate its fallen astronauts. At space centers across the country, flags were lowered to half-staff, with ceremonies held along with spaceflight safety discussions.
Saturday marks the 37th anniversary of the Challenger tragedy.
Along with experienced astronauts, the shuttle carried Christa McAuliffe, who was set to be the first teacher in space. The New Hampshire woman had been selected to join and teach lessons from space to children around the country.
Months after the incident, an investigation found that the two rubber O-rings, which were designed to separate sections of the rocket booster, failed due to weather. The shuttle launched on a cold Florida morning despite behind-the-scenes concerns from engineers, a 2021 NASA article states.
"We will never forget these astronauts, nor all those who have lost their lives in the pursuit of discovery," NASA Administrator Bill Nelson said in a video posted Thursday by the space agency. "And so on this Day of Remembrance, we honor and try to better understand our place in this huge, huge universe and our attempts at discovery and exploration in it."
Vice President Kamala Harris also commemorated the tragedies in a Thursday Twitter post: "The crews of Apollo 1 and Space Shuttles Challenger and Columbia are always in our hearts as our Nation continues their legacy."
The Associated Press contributed to this report.