Helen Sharman, Mark Shuttleworth, and Richard Garriott) and/or foreign citizenship (held by astronauts Michael Foale, Gregory H. Johnson, Piers Sellers, Nicholas Patrick, Shuttleworth, and Garriott). As part of his extensive astronaut training in 2011, Peake and five other astronauts joined an international mission, living in and exploring cave systems in Sardinia. This ESA CAVES mission enabled them to study how humans react to living in extreme conditions with complete isolation from the outside world. This expedition gave the team an idea of what they could expect and how they would cope in the confined space of the ISS. On 16 April 2012, NASA announced that Peake would serve as an aquanaut aboard the Aquarius underwater laboratory during the NEEMO 16 undersea exploration mission, scheduled to begin on 11 June 2012 and last twelve days. The NEEMO 16 crew successfully "splashed down" at 11:05 am on 11 June. On the morning of 12 June, Peake and his crewmates officially became aquanauts, having spent over 24 hours underwater. The crew safely returned to the surface on 22 June. During Expedition 44 Peake served as a backup astronaut for Soyuz TMA-17M spaceflight. Expedition 46/47 Peake was launched to the space station (ISS), on 15 December 2015, for Expeditions 46 and 47. He launched successfully at 11:03 GMT from Baikonur Cosmodrome on board Soyuz TMA-19M. The official website dedicated to his mission is principia.org.uk. During the launch, as per tradition, each cosmonaut was allowed three songs to be played to them. Peake chose Queen's "Don't Stop Me Now", U2's "Beautiful Day" and Coldplay's "A Sky Full of Stars". During docking, the Kurs docking navigation system failed, and a manual docking was performed by Yuri Malenchenko who was alongside Peake and Tim Kopra. This delayed docking with the ISS by 10 minutes. The Soyuz finally docked with the ISS at 17:33 GMT. Peake received messages of support from the Queen and Elton John, after the successful docking. His first meal at the ISS was a bacon sandwich and a cup of tea. A new year's message by Peake was broadcast by the BBC to celebrate 2016. Peake supported a spacewalk by two American astronauts on 21 December 2015. He participated in the first spacewalk outside the ISS by a British astronaut on 15 January 2016. The purpose of the spacewalk was to replace a faulty sequential shunt unit on the station's solar arrays. At the