There’s a little bit of water inside each kernel of popcorn, and if you can heat the kernel above 212°F, that water should boil, turn into high-pressure steam, and pop the kernel. But in orbit, things aren’t so simple. First off, the cold vacuum of space would suck all the water out of the kernel before it could pop the corn. So any ordinary kernels would drop, not pop. But let’s say we figured out a way to keep the kernel watertight. In that case, it all depends.