Engineering Memory of the Month

Research in free-fall

People often overlook (or simply don't know) that astronauts are never fully outside the Earth’s gravity, but are instead in free-fall as they orbit. The net effect, however, is the same: they float around as if they were weightless. The ability to replicate free-fall, at least briefly, on Earth means that in certain circumstances, engineers can re-create space-like conditions in the lab.

That’s what the drop mechanism in this picture from 1963 did. It allowed mechanical engineering researchers to study fluid properties such as surface tension in an environment with no apparent gravity. The goal was to better understand what was going on inside the propellant fuel tanks of spacecraft. Looking up at the device were (l. to r.) Professors William Kays and William Reynolds and student Hugh Satterlee. In the case of this research 45 years ago, the space race was a race to the bottom.

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