On the morning of 28 January 1986, the NASA space shuttle Challenger launched from the Kennedy Space Center.
73 seconds later, the spacecraft exploded, killing all seven crew members on board as their families and other spectators watched on in horror.
Many tuned in to watch the Challenger's launch due to the presence of Christa McAuliffe, a teacher who was meant to give lessons from space as part of a US government program.
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Her presence gave the shuttle launch greater media attention, and many children were watching the launch from school too.
Footage of the horrific disaster captured the reactions of the spectators who had come to see what they thought was a routine space shuttle launch.
At first, the spectators were all cheers and applause as everything seems to be going well before their faces turned to horror and some started screaming as they witnessed the moment the space shuttle exploded.
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Some spectators initially didn't realise exactly what had happened before it began to sink in that the launch had gone horribly wrong.
The footage prominently features McAuliffe's parents, who could only look on in disbelief as the space shuttle with their daughter onboard exploded before their very eyes.
Some people in the crowd held each other in distress, while others could do nothing but keep looking skyward at the site of the disaster in the hopes that some other development might reassure them.
Announcements were made to tell the spectators that 'the vehicle has exploded' and the crowds were ushered away to assurances that they would hear more when more details became known.
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A piece of the Challenger shuttle was discovered last year on the ocean floor by a History Channel documentary team who dived down off the Florida coast.
Divers uncovered a segment from the rocket's heat shield which was confirmed to belong to the Challenger after the discovery was turned over to NASA for inspection.
Their experts made sure the debris had come from the Challenger and hailed it as the first finding of a piece of the space shuttle in 'more than 25 years'.
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The Challenger exploded due to the failure of O-ring seals in the right hand side solid rocket booster (the white rockets either side of the big orange one attached a space shuttle) after record low temperatures at the launch site caused them to fail.
Challenger broke into pieces 46,000 feet above ground and subsequent investigations into the disaster have found that some of the crew members survived the initial explosion.
However, the loss of cabin pressure would have rendered them unconscious within seconds and they would have died of oxygen deficiency shortly before the cabin hit the ocean surface at 207mph.
Joe Harker