A former army helicopter pilot was on Monday named as the first "home-grown" British astronaut to head to the International Space Station.
Major Tim Peake, 41, will fly out to the ISS in November 2015 as part of a six-man crew, becoming the first Briton ever to travel to space on a British government-funded mission.
British-born astronauts have previously gone into orbit as US citizens through NASA, or on privately-funded ventures organized with Russian help.
Peake said it was a "true privilege" to have been chosen from more than 8,000 applicants for the six-month mission.
"The mission to the International Space Station is going to be a wonderful opportunity, not just for Europe and European science but the UK as well," he said at a press conference in London.
Prime Minister David Cameron said it was "a momentous day, not just for Tim Peake but for Great Britain".
"I am sure he will do us proud and I hope that he will inspire the next generation to pursue exciting careers in science and engineering," the prime minister said.
Peake, who will be on board the ISS for six months, has swiftly been dubbed "Major Tim" in reference to David Bowie's 1969 song "Space Oddity", which tells the tale of lonely astronaut Major Tom.
He uses Twitter under the handle @astro_timpeake, and there are hopes he could take over from Canadian astronaut Commander Chris Hadfield as the ISS's chief tweeter.
Hadfield, who returned to Earth last week, delighted Twitter users during his six-month mission with spectacular images taken from the ISS and insights into daily life in space.
He even posted a video of himself singing "Space Oddity" as he floated in zero gravity with his guitar.
Peake confirmed that he would be tweeting from the space station, but he added: "I do play the guitar, but very badly, and I wouldn't inflict my singing on anybody."
His tweets would hopefully "encourage a generation to take an interest in space", he told journalists.
During his mission Peake will work on a range of experiments and will potentially have the opportunity to conduct a spacewalk.
The team will lift off to the ISS from Kazakhstan in a Soyuz rocket.
Britain has traditionally refused to get involved in the funding of human space flight due to the huge cost, but its interest in the sector has grown in recent years.
Cameron said Peake's mission was "a great sign of our thriving British space sector, which has seen real growth thanks to our world-class research, and now supports nearly 30,000 jobs".
Helen Sharman became the first Briton in space in 1991, spending eight days at the now-defunct Mir Space Station as part of the Soviet mission Project Juno.
The most experienced British-born astronaut is NASA's Michael Foale, who has completed missions to both Mir and the ISS.