For those vehicles to work together in space, they will need a set of standard interfaces that allow them to rendezvous, transfer payloads, dock and refuel in orbit. Standard interfaces will make it easier for new vehicles to be developed and join the network. ESA believes this system should establish a European standard, so that the transportation network can operate independently of support from outside of Europe.

Helping the European private sector to develop such technological building blocks is an important focus of ESA's Future Launchers Preparatory Programme (FLPP). Indeed, ESA's vision for its own transformation is to become one client among many of an independent and impactful European space industry. In this model, ESA – often working through FLPP – acts as a key enabler.

One current project aims to help private sector partners develop proof-of-concept in-space transportation vehicles. These vehicles will be able to dock with target spacecraft and cargo in-orbit, take on payloads, carry them to their final orbits – and refuel themselves from orbiting propellant depots.

A first phase was successfully performed by consortia selected by ESA – led by D-Orbit, The Exploration Company, OHB System, S.A.B. Aerospace and Thales Alenia Space France. Now, the project is moving on to a second phase, where preliminary designs will be developed with a view to flying a proof-of-concept mission in two to three years.