The Challenger Disaster It was on January 28, 1986 at 11:38 am that the shuttle Challenger, NASA Flight 51-L, the twenty-fifth shuttle flight, took off. It was the "Teacher in Space" mission. At liftoff, the temperature at ground level was 36° Fahrenheit, which was 15° Fahrenheit colder than any previous NASA launch. It was the Challenger's tenth flight. Takeoff was delayed several times. Finally the shuttle had taken off. The shuttle had climbed high into the sky thirty-five seconds after takeoff and was being battered by strong winds. The onboard computers continually made adjustments to keep the shuttle on course. About eight miles up, about seventy-two seconds after liftoff, people watched in fear and horror as the shuttle was engulfed in a massive fireball. All crew members were killed instantly. Engineers and scientists almost immediately began trying to find out what went wrong. They studied the takeoff footage. While observing the footage, they noticed a small jet of flame coming from inside the casing of one of the rockets. The flame got bigger and bigger. He began touching a strut that connected the booster to the large fuel tank attached to the Space Shuttle. About two or three seconds later, hydrogen began to leak from the giant fuel tank. About seventy-two seconds after liftoff, the hydrogen ignited and the booster spun. This punctured the fuel tank, causing a large explosion. Even though people knew what happened, they didn't know why it happened. Gradually people found the answer. Here's why it happened: the rocket casing was made in several sections. These sections were attached to each other and sealed together with rubber O-rings. The O-rings were held in place by the pressure of hot gases, which came from the rocket after ignition. On previous Challenger missions, the O-rings were found to be worn out by hot gases. O-rings had been tested and the results had shown that they were much more likely to crack in cold or freezing weather conditions. This was what happened on the cold morning of January 28, 1986. The people aboard the shuttle on January 28, 1986 were Lieutenant Ellison Onizuka, an Air Force officer; Commander Michael Smith, a Navy officer; Christa McAuliffe, a high school teacher in New Hampshire; Dick Scobe, a Navy officer; Greg Jarvis, an engineer; Judy Resnik, an astronaut; and Ronald McNair, an astronaut.