Some satellites require fuel, and, as it turns out, fuel is very heavy. Once a satellite runs out of said fuel, it’s no longer fully operational.

For that reason, researchers are developing refueling stations for use in space with new techniques to overcome some challenging hurdles in liquid dynamics.

Last year, startup Orbit Fab successfully completed the first set of experiments to see if water could be transferred between two satellite test beds. Orbit Fab has been working with satellite manufacturers on something called the Rapidly Attachable Fuel Transfer Interface, or RAFTI, which is a new kind of valve system that would allow satellites to be fueled on the ground before launch and, someday, refueled in space. This would eventually allow more satellites to stay in orbit and help reduce the creation of new space junk.