Nothing works as it’s supposed to in zero gravity, or zero G, as it’s also known. “Even something as simple as a fuse,” astronaut Chris Hadfield told me, mistaking me for someone who knows how a fuse works. Now I know: Fuses have a metal strip that melts in response to a surplus of current. The molten bit drips away, leaving a gap that interrupts the power flow. Without gravity, the droplet doesn’t drip, so the power continues to flow until the metal boils, by which time the equipment has fried.
