The U.S. Southwest Research Institute (SwRI) and Astroscale U.S. are collaborating on the development and testing of a satellite refueling spacecraft. The Astroscale Prototype Servicer for Refueling (APS-R) will extend satellite missions by delivering hydrazine propellant to these vehicles while in geostationary orbit around Earth.

As part of the U.S. Space Force-funded project, the host vehicle for the APS-R will be constructed by SwRI with maximum dimensions of 24 inches by 28 inches by 45 inches when stowed for launch, and a total vehicle launch mass of 437 lb, including propellant. The completed system will be integrated with the Astroscale-supplied payload and subjected to system-level environmental testing in preparation for vehicle launch.

The fuel transfer will be facilitated by the use of the Rapidly Attachable Fuel Transfer Interface docking system engineered by Colorado-based Orbit Fab. Designed to be installed on satellites, this equipment will support the propellant refueling in orbit.

“Recently, other approaches to life extension have emerged, such as a vehicle that can use its thrusters to push another spacecraft where it needs to go after it runs out of fuel,” said SwRI project systems engineer Steve Thompson. “A refueling vehicle broadens life extension options with a flexible alternative.”

The launch-ready APS-R is expected to be delivered by 2026.