There were caves beneath the Moon’s surface. According to NASA, the project could become the first mission designed to explore caves on another world. Stone Aerospace’s proposed Lunar Underground eXplorer, or LUX, would descend into a massive hole in Mare Tranquillitatis, the same general area where Apollo 11 landed. A Laser-Powered Drone Could Be the First Mission to Explore Caves on Another WorldThe drone itself sounds like the stuff of science fiction. It doesn’t carry a bulky battery, and instead would remain connected to a rover on the surface via a fiber-optic tether.