Outline of the proposed Hermes spaceplane programme. Hermes, with a crew of three, was to have been launched from the Guiana Space Centre by an Ariane 5 rated for human spaceflight. Hermes would have serviced the Columbus Free Flyer, an experiment platform in low Earth orbit, performed experiments in orbit, visited what was then called Space Station Freedom, now the International Space Station (ISS), or serviced the unmanned remote sensing Polar Platform (PPF).

The Hermes programme was cancelled in 1992 and plans for an Ariane 5 rated for human spaceflight were abandoned as a consequence. The Columbus Free Flyer was abandoned prior to the start of Phase C/D (detailed design and manufacturing) for cost reasons. The Polar Platform adopted some components from the French HELIOS satellite and eventually became the common platform on which Envisat and the MetOp satellites were built.