NASA rocket fuel experiment. Footage of NASA engineers carrying out a drop test experiment to determine how liquid hydrogen in a rocket tank behaves in zero gravity The clip starts with a view of the tower where the test tank is dropped, followed by engineers preparing the tank. The test tank is then seen falling down the tower in free-fall, replicating the effects of microgravity in Earth orbit. The remaining part of the clip is high-speed footage of the liquid hydrogen fuel inside the tank. NASA was established in 1958.