LONDON, ENGLAND - MAY 20: Members of the European Association of Space Explorers (L-R) Michel Tognini, Franz Viehbock, Ernst Messerschmidt, Sergei Krikalev and Helen Sharman celebrate 25 years since Ms Sharman's space mission hosted at the Science Museum on May 20, 2016 in London, England. Ms Sharman became the first Briton into space and the first female astronaut to visit the Mir space station in 1991, as part of Project Juno, a UK-Soviet cooperative programme. (Photo by Jack Taylor/Getty Images)
