27 years ago, the worst tragedy in space exploration occurred, in which 7 astronauts lost their lives when the space shuttle Challenger exploded after take-off.
The explosion happened 73 seconds after the Challenger was airborne, at around 16km above sea level. And although the crewmembers did not die instantly, like one would think. The cabin did not suffer any damages, but was shot up in the air about 5km more after the explosion, and descended towards the earth at a speed rate of 333km/hr into the sea and disintegrating completely on impact.
Regarding the details about the safety measures of the cabin, the Titanic effect took place, in which NASA had previously felt that an escape system was not necessary, due to that they considered it to be a very safe and secure shuttle.
Among the crewmembers on board was Christa McAuliffe, who was a teacher from Concord, New Hampshire, and winner of the NASA's "Teacher in Space Program" who would be the first civilian to travel in a space mission.
Astronauts Dick Scobee and Michael J Smith remains were buried in individual graves, and everyone else was buried together at the Arlington National Cemetery.
After this tragedy the space program was put on hold for 32 months, until the space shuttle Discovery was introduced which then soon after the Challenger's successor the "Endeavour" made its first flight.
VIDEO: Challenger Tragedy (courtesy CNN)