This image, from a future of human spaceflight presentation given on 29 January at the EADS Astrium site in Bremen, Germany, is one of the concepts undergoing trade studies for the joint European Space Agency-Russian Federal Space Agency Crew Space Transportation System preparatory programme.

"This is one of the numerous ideas being traded for CSTS. We [are] working towards defining the vehicle concept. It is taking a bit longer than planned," says Manuel Valls, CSTS programme manager and head of policy for the ESA's human spaceflight, microgravity and exploration directorate.