Early on in the latest Indiana Jones installment, Dr. Jones survives the blast from a nuclear explosion by hiding in a lead-lined fridge. Oddly enough, this may be one of the more realistic stunts in the movie. When we think of nuclear explosions, we tend to imagine a fireball that annihilates absolutely everything within a certain radius. But in fact it is possible for man-made objects to survive an atomic blast, relatively intact, in even the heart of the nuclear explosion. During a 1954 15-megaton atomic bomb test, two steel balls covered in graphite were hung from the bomb tower. Incredibly the balls survived—but were thrown a considerable distance from the bomb site. This led scientists, including the famed Freeman Dyson, to consider the possibility of using nuclear bombs to propel spacecraft through space. A stream of relatively low-power bombs would be shot out behind the spacecraft, and as each one detonated, radiation pressure would force the spacecraft forward. The concept was known as the Orion drive, and in theory it could have allowed us to fly to the outer planets and back in just a few weeks, instead of the years required for today's space probes. However, despite some interesting early research work, Orion was killed off with the signing of the 1963 limited test ban treaty, which specifically banned nuclear explosions in the atmosphere or outer space—and made mushroom clouds perfect for 1950's period pieces such as Indiana Jones.