Europe’s ASTRAL mission will test Orbit Fab’s RAFTI refueling technology in orbit

Questions and Answers: 

What is the goal of the ASTRAL mission? ASTRAL aims to conduct Europe’s first in-orbit refueling experiment, validating hardware and procedures needed to refuel satellites in space and extend mission lifetimes.

What technology will be tested during the mission? The mission will test Orbit Fab’s RAFTI and GRASP interfaces in an operational environment, including docking, leak-free connections, and the transfer of multiple propellants such as nitrous oxide, ethane, and Xenon.

Who is funding the project? The project includes up to $3.8 million in UK funding, with a $1.7 million first-stage contract awarded through ESA’s ARTES Core Competitiveness program.

BREMEN, Germany - Orbit Fab, a Lafayette, Colo.-based company developing in-orbit refueling and long-term space logistics, has reached a new milestone in its efforts to support sustainable satellite servicing with the awarding of two contracts. 
The company will deliver the Advancing Satcom Technology with Refueling and Logistics (ASTRAL) project with up to $3.8 million in total U.K. funding. The European Space Agency’s (ESA) Advanced Research in Telecommunications Systems Core Competitiveness program has awarded Orbit Fab a contract valued at $1.7 million for the first stage of the mission.

ASTRAL will conduct an in-orbit experiment by 2028 to test Orbit Fab’s RAFTI and GRASP refueling interfaces under operational conditions. The mission is intended to validate docking performance and propellant transfer in space, a key step toward enabling refuelable satellites and long-duration missions.

The ASTRAL consortium includes Orbit Fab, KISPE Space Systems, Gate Space Innovation GmbH, Blackswan Space, and Indra Deimos. The partners, representing organizations in the UK, Austria, and Lithuania, will conduct Europe’s first in-orbit Xenon refueling experiment. The mission aims to advance the design and validation of hardware that supports satellite sustainability and maneuverability in increasingly crowded orbits.

Related: Momentus, Orbit Fab to launch space domain awareness and refueling tech demo

Demo goals

During the mission, ASTRAL will demonstrate docking, leak-free connections, and the transfer of multiple propellants including nitrous oxide, ethane, and Xenon through the RAFTI system. It will also validate rendezvous, proximity operations, and safe release procedures.

ASTRAL is a multi-purpose activity co-funded through ESA’s ARTES program. The mission is supported by the UK Space Agency and national delegations from Lithuania, Austria, and other participating nations. It is intended to mature hardware and operational procedures needed for in-orbit spacecraft refueling, with completion targeted for 2028.

"We are proud that Orbit Fab will lead Europe’s first in-orbit test of satellite refueling. Through the support of the ESA ARTES we are bringing together technology developed in Austria, Lithuania, the UK and beyond with our proven RAFTI interface to conduct the world’s first in orbit fueling of Xenon," Jacob Geer, managing director of UK and Europe at Orbit Fab, said. "Developing the European capability now is vital to extend the life of communication satellites and make defense spacecraft more maneuverable and resilient."

Orbit Fab is developing refueling infrastructure to support long-duration commercial, scientific, and defense space missions. The company, headquartered in Colorado, operates a UK subsidiary established in 2022. Its achievements include resupplying the International Space Station and developing a refueling valve approved by the U.S. Space Force. RAFTI, the Rapidly Attachable Fluid Transfer Interface, is an open-license docking and refueling standard designed to replace traditional fill and drain valves.

ESA’s Core Competitiveness program within ARTES supports satellite communications innovation through funding and technical expertise. The program helps organizations advance technologies from early concepts to market-ready products and services across Europe and Canada. It includes two components, ARTES Advanced Technology and ARTES Competitiveness and Growth, to help organizations develop solutions throughout the full development cycle.