In an effort to address the issue of running out of fuel among thousands of satellites and spacecraft in geostationary orbit at an altitude of approximately 35,800 km above the equator, the Southwest Research Institute (SwRI) in the US is developing a small spacecraft prototype called Astroscale Prototype Servicer for Refueling (APS-R). SwRI has been awarded $25.5 million for this project as part of the Space Mobility and Logistics pilot project funded by the US Space Force.
The APS-R will move in a circular orbit that matches the Earth’s rotation period and will transport hydrazine propellant from storage to satellites in need of refueling. It can provide refueling services to any spacecraft equipped with a compatible refueling port in geostationary orbit. SwRI aims to build a “spaceship bus” to carry APS-R to space within the next 16 months, with maximum dimensions of 61 x 71 x 114 cm when stowed for launch and a launch mass of 198 kg including propellant.
Development of the spacecraft bus will take place at SwRI’s new Space Systems Orbiter and Payload Handling Facility, where they can quickly assemble and test small spacecraft. Once the spacecraft bus is complete, SwRI will integrate cargo provided by Astroscale and conduct environmental testing in preparation for launch. The APS-R ship is expected to be ready for launch in 2026.
