Space exploration has been marked by incredible achievements but it has also been shadowed by tragedies
Here are five of the deadliest disasters in spaceflight history that remind us of the risks and sacrifices made in the quest to explore the universe
Mission: Soyuz 11
On June 30, 1971, the Soyuz 11 crew died tragically when a cabin vent valve malfunctioned during reentry, causing fatal decompression after undocking from Salyut 1
Mission: Soyuz 1
On April 24, 1967, Soyuz 1 ended tragically when parachute failure caused the capsule to crash, killing cosmonaut Vladimir Komarov. A memorial stands near the site
Mission: X-15 Flight 3-65-97
On Nov. 15, 1967, electrical and control issues caused pilot Michael Adams’ X-15 to spin at Mach 5, leading to structural failure and his tragic loss
Mission: Space Shuttle Challenger Disaster
On January 28, 1986, Challenger exploded 73 seconds after liftoff due to an O-ring failure, killing all seven crew members upon impact
Mission: Space Shuttle Columbia Disaster
On February 1, 2003, Columbia broke apart while reentering Earth’s atmosphere due to thermal protection damage, scattering debris over California, Texas, and Louisiana