“We have two pressurized fuel tanks linked to two pairs of thrusters. Rather than burning propellant, these are simpler ‘cold-gas’ thrusters designed specifically for such a small mission. And simpler means cheaper and smaller. The fuel is stored under pressure, then released through a tiny rocket nozzle. Even though it’s cold gas, we achieve a substantial velocity change by using liquid butane that turns to gas as it exits. Storing it as a liquid, like in a cigarette lighter, allows us to pack as many butane molecules as possible inside the small available volume – its liquid form being some 1000 times denser than its gas.”
Source: Tor-Arne Grönland, head of NanoSpace, describing how ESA&rsquo