LONDON, ENGLAND - MAY 20: British astronaut Helen Sharman (2nd-L) poses with her crew from the Soyuz TM-11 mission Sergei Krikalev (L), Anatoli Artsebarski (R) and their commander Viktor Afanasyev at an event to mark 25 years since her space mission hosted by 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)

LONDON, ENGLAND - MAY 20: Badges on the jacket of European Space Agency astronaut Jean-Francois Clervoy are displayed at an event to mark 25 years since British astronaut Helen Sharman's space mission 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)

LONDON, ENGLAND - MAY 20: British astronaut Helen Sharman (2nd L) poses with her crew from the Soyuz TM-11 mission Sergei Krikalev (L), Anatoli Artsebarski (R) and their commander Viktor Afanasyev at an event to mark 25 years since her space mission hosted by 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)

LONDON, ENGLAND - MAY 20: British astronaut Helen Sharman attends an event to mark 25 years since her space mission hosted by 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)

LONDON, ENGLAND - MAY 20: The space suit of British astronaut Helen Sharman is on display 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)

LONDON, ENGLAND - MAY 20: Members of the European Association of Space Explorers and the crew from the Soyuz TM-11mission (back row L-R) Jean-Loup Chretien, Jean-Pierre Haignere, Michel Tognini, Franz Viehbock, Ernst Messerschmid, Sergei Krikalev, Helen Sharman, Claudie Haignere, Dumitru Prunariu, Anatoli Artsebarski, Viktor Afanasyev and (front row L-R) Reinhold Ewald, Jean-Francois Clervoy and Andreas Mogensen pose 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)

LONDON, ENGLAND - MAY 20: British astronaut Helen Sharman attends an event to mark 25 years since her space mission hosted by 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)

LONDON, ENGLAND - MAY 20: European Astronauts Jean-Loup Chretien (L) and Michel Tognini (R) attend an event to mark 25 years since British astronaut Helen 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)