Viewing the footage of the Challenger disaster, it’s easy to conclude that the shuttle exploded. There is a large fireball quickly followed by the disintegration of the rocket and shuttle. But a closer look at the evidence shows that the breakup technically wasn’t an explosion at all.
Essentially, the root cause of the disaster was a fuel leak in the shuttle’s right solid fuel rocket booster. During the launch, that escaping fuel caught fire, weakening connections between the booster and the large liquid fuel rocket. Eventually, the booster broke loose, swung around, and pierced the liquid fuel tank, releasing liquid oxygen. The liquid hydrogen fuel tank had also already been compromised by the fire and had begun to leak as well. When the two fuels mixed, they ignited and created the large fireball seen in the footage. However, the boosters actually survived this catastrophic failure and continued flying on their own until NASA officials remotely detonated them over the Atlantic.
The shuttle also survived the fireball — for a short while, anyway. It continued flying for a moment but, soon after breaking away from the fuel tanks, the aerodynamic forces acting upon it tore the craft apart. Ultimately, though the fireball and subsequent breakup were dramatic and catastrophic, it had few of the auditory or physical effects of an explosion, such as a shockwave or loud noise. Instead, those on the ground likely heard something more chilling: silence as the rockets cut out.