The Challenger Disaster was a tragic incident that occurred on January 28, 1986, when the NASA Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the death of all seven crew members on board. The disaster was a significant setback for NASA and raised questions about the safety and viability of space travel.
…. The year 1986 was shaping up to be the most ambitious one yet for NASA’s Space Shuttle Program. The agency’s plans called for up to 15 missions, including the first flight from the West Coast launch site at Vandenberg Air Force Base in California. Other important missions included the launch of two planetary spacecraft with very tight launch windows, an astronomy mission to study Halley’s Comet, and the launch of the Hubble Space Telescope. The first mission of 1986, STS-61C, delayed from December 1985, flew between Jan. 12 and 18. The next flight, designated STS-51L, marked the 25th in the program and the 10th for space shuttle Challenger. During the six-day mission, the seven-member crew was to deploy a large communications satellite, deploy and retrieve an astronomy payload to study Halley’s Comet, and the first teacher in space would conduct lessons for schoolchildren from orbit.
See full NASA Tribute to Teacher McAuliffe:
35 Years Ago: Remembering Challenger and Her Crew
The Challenger Space Shuttle Disaster - Explained (Minute by Minute)