GomX-4_pair
Two mini-satellites are launching into orbit soon, the GomX-4A and GomX-4B. GomSpace/ESA

Engineers have built the space version of a cigarette lighter to power a satellite that’s set to launch soon, allowing it to change orbit while it flies around the Earth. The thrusters run on butane and will be attached to GomX-4B when it launches into space from China on Feb. 2, the European Space Agency said.

It will head up at the same time as another satellite, GomX-4A, so the duo can work on an experiment together: They will have a space rendezvous designed to test out radio communications between the pair, including how they hold their link across different distances to share data with each other and with Earth.

GomX-4A is a satellite for the Danish Ministry of Defense while GomX-4B is the ESA’s project.

Like its counterpart, the new ESA satellite is small and constructed from CubeSat units. It is about the size of a cereal box and made from six of the 4-inch units.

The ESA has referred to them as “twins,” but the butane power will make them fraternal.

“The thrusters fitted along one side will allow it to adjust its motion by a total of 15 m/s — a speed equivalent to a kicked football,” the ESA said.

After getting their antennas lined up, GomX-4B will use its power to create distance between itself and its twin, testing the radio link at intervals. The thrusters are attached to pressurized fuel tanks.

But there won’t be any fire: “Rather than burning propellant, these are simpler ‘cold-gas’ thrusters designed specifically for such a small mission,” Tor-Arne Grönland, head of the Swedish firm Nanospace that designed the thrusters, said in the agency’s statement. “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 1,000 times denser than its gas.”

Apart from the radio testing, GomX-4B is carrying an instrument to image the planet in different wavelengths across the electromagnetic spectrum.

The ESA’s Roger Walker said through an agency statement that the satellite would be “gathering a wealth of environmental data — so much so, in fact, that the camera must perform its own processing to drastically reduce the amount needing to be sent back to the ground.”