According to tracking service Orbiting Now, there are currently 9,707 satellites orbiting the planet right now. When some of those satellites run out of fuel, their usefulness is over and they become space junk rather than space-based tools – even if they're in otherwise good health. To help solve this issue, in January the United States Space Force (USSF) awarded US$25.5 million to orbit-service provider Astroscale U.S. to create a refueling solution, as part of a larger program focused on keeping government satellites operational after their tanks are empty.

"The advent of in-air refueling completely changed the equation for the duration and distance of aircraft missions," said Astroscale's, Ron Lopez at the time. "The space industry is on the cusp of a similar fuel-led technological revolution, and I am thrilled that SSC has selected Astroscale U.S. to develop APS-R to bring fuel to its client spacecraft.

"This innovation in on-orbit servicing will ultimately extend the range and mobility of satellites in orbit, allowing the USSF to do more with their operational assets. APS-R opens the door to rethinking the way satellites are designed and operated, marking a significant leap forward in the capabilities and sustainability of satellites in orbit."

This week, Astroscale U.S. tapped the Southwest Research Institute (SwRI) to build the host bus for the refueling system, which they have dubbed the Astroscale Prototype Servicer for Refueling (APS-R).

Over the next 16 months, SwRI will begin constructing the fuel transport craft at a new 74,000-square-foot facility in Texas. It will measure a modest 24 x 28 x 45 in (61 x 71 x 114 cm) and have a mass of 437 lb (198 kg) when it is linked to the refueling package from Astroscale. The bus is expected to be launch-ready by 2026.

The system will enter a geostationary orbit, meaning that it will remain in orbit over a fixed point on the planet. It will carry a propellant known as hydrazine that it will pick up from a depot that's also in geostationary orbit and deliver it to a spacecraft in need of fuel. SwRI says that the system will work with any spacecraft with a compatible refueling port.