Space Shuttle Challenger: It's been 38 years since explosion claimed the lives of its entire crew

It's been 38 years since NASA's space shuttle Challenger went up in flames within two minutes of launching – killing an entire crew.

On January 28, 1986, seven crew members boarded the space shuttle Challenger at the Kennedy Space Center in Cape Canaveral, Florida hoping to launch the second Tracking and Data Relay Satellite (TDRS-B).

The Challenger also carried the Spartan Halley spacecraft – a small satellite that was going to be released and picked up two days later after observing Halley's Comet during its closest approach to the sun.

Who was the part of the Challenger crew?

There were seven crew members onboard the Challenger spacecraft, one of whom was a teacher. Christa McAuliffe was the winner of a 1984 national screening and was to teach two lessons from orbit and then spend the next nine months lecturing students across the U.S.

ULA launches new Vulcan rocket from Florida, sending science to the moon

<div>Photo shows NASA's Challenger crew posing for photographs on Jan. 9 1986 | Credit: NASA</div>
Photo shows NASA's Challenger crew posing for photographs on Jan. 9 1986 | Credit: NASA

Commander Francis (Dick) Scobee, pilot Michael Smith, mission specialists Ellison Onizuka, Judith Resnik, and Ronald McNair, and Huges Aircraft engineer Gregory Jarvis were the other six crew members.

What happened to the Challenger?

The Challenger took off at 11:38 a.m. and everything seemed normal until the rocket emerged from its period of greatest aerodynamic pressure. After Mission Control told Scobee to "go with throttle up" the rocket exploded within 73 seconds of being in the air.

Salvaged tapes from the wreck showed that the last word before the explosion was Smith saying, "Uh-oh."

What caused the Challenger explosion?

The mission had several delays and setbacks leading up to the January 28 launch. Some delays were due in part to a previous shuttle mission Columbia needed to get back on the ground.

The night before the Challenger launch, all of Central Florida was dealing with a wave of cold temperatures resulting in a thick ice layer that was deposited on the launch pad.

Within days of the accident, it was suspected that severe cold weather reduced the resiliency of two rubber O-rings that sealed the joint between the two lower segments of the right-hand solid rocket booster.

Central Florida family sending loved ones ashes to final resting place in space

<div>Photo shows the STS-51L mission clear the tower at Launch Complex 39B at NASA's Kennedy Space Center | Credit: NASA</div>
Photo shows the STS-51L mission clear the tower at Launch Complex 39B at NASA's Kennedy Space Center | Credit: NASA

Under less frigid weather conditions, when the shuttle's three main engines ignited, they pressed the whole shuttle forward and the boosters were ignited when the vehicle swung back to center.

On the morning of the explosion, an effect called "joint rotation" happened. This prevented the rings from resealing and opened a path for hot exhaust gas to escape from inside the booster. Puffs of black smoke appeared on the far side of the booster in a spot not visible to many cameras.

As the shuttle ascended, after about 59 seconds, a stream of flame appeared from the hole eventually eroding one of three struts that secured the booster's base to a tank carrying liquid hydrogen and liquid oxygen for some of the engines.

When the strut broke, the booster's base swiveled outward and was forced through the top of the external fuel tank causing the entire tank to collapse and explode.

Who is to blame?

On June 6, the Rogers Commission report was delivered to the president faulting NASA, its Marshall Space Flight Center in Huntsville, and contractor Morton Thiokol Inc. in Ogden, Utah for poor engineering and management.

Several engineers expressed concerns about the reliability of the seals for two years. They warned management about a possible failure the night before the launch.

In response to the criticism, NASA added more checkpoints to its shuttle program to prevent a dangerous decision regarding a launch happening again.