The Apollo 15 Hammer-Feather Drop
At the end of the last Apollo 15 EVA, on August 2, 1971, Commander David Scott performed a live demonstration for the television camera. He held out a 1.32-kg aluminum geologic hammer and a .03-kg falcon feather and dropped them both at the same time. Because they were in a vacuum, there was no interfering air resistance and the feather fell at the same rate as the hammer, just as Galileo had surmised in 1589 - all objects released together fall at the same rate regardless of mass.
Source: http://nssdc.gsfc.nasa.gov/planetary/...
Video: NASA