Since the CubeSat specification was developed in 1999 by Stanford and California Polytechnic, low-cost satellites have become a reality for academic institutions and companies around the world. Their standardized dimensions and off-the-shelf components make for simpler design and production, but theres a problem: these 10-centimeter cubes, used widely in fields such as meteorology, communications, and aeronautics, are limited by Earths orbit. Now, a team of researchers wants to change that — making interplanetary exploration more affordable by crowdfunding the development of a novel thruster that uses water as its fuel. Their CubeSat Ambipolar Thruster, or CAT, works in a similar way to existing rocket thrusters — by heating up a propellant and expelling it through a nozzle.