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Michael Foale, the most experienced British-born astronaut in the history of human spaceflight, has retired from Nasa.

Holding dual US-UK citizenship, .

In his 26-year career in Nasa's astronaut corps, he flew on numerous shuttle and Soyuz missions.

He serviced the Hubble telescope, and had tours on both the Mir platform and the International Space Station.

The latter he commanded in 2003.

Dr Foale is leaving the agency to work on advancing green aviation technology, by helping to develop an electric aircraft.

Born in Louth, Lincolnshire, Michael Foale went to school in Canterbury, Kent, and received his astrophysics PhD from Cambridge. He then departed the UK shortly afterwards to pursue his dream of going into orbit by joining the US space agency. This required he become a US citizen.

The Nasa administrator, and former fellow astronaut, Charlie Bolden, paid tribute to Dr Foale.

"We salute Mike and his contributions to Nasa as an accomplished member of the astronaut corps," General Bolden said in a statement.

"Starting with his first flight, shuttle mission STS-45, when we flew together in 1992, Mike has worked tirelessly to support Nasa's quest to explore the unknown. I know Mike will go on to do more great things as he continues to support the aerospace industry in his new endeavour."

One of the most dramatic events in Dr Foale's career occurred on Mir in 1997 when the Russian space station was rammed by a visiting cargo ship.

He later recalled to the ����ý: "It weighed about seven tonnes so the impact was very noticeable. We heard a big thud and I remember having a severe adrenalin rush and thinking about how much longer do we have.

"I felt the fall of the air pressure in my ears and realised it was fairly severe but not so severe that we wouldn't have time to evacuate. It all started to fit together and a plan even started to form in all our minds that we would be ok - or we could be ok."

Dr Foale made a total of six trips into space and at one point held the record for the most cumulative time in orbit for a US astronaut.

Like most of the British-born individuals who have flown in space, Michael Foale had to take the Nasa route to achieve his goals. For years, successive UK governments deemed human spaceflight to be a waste of money and refused to fund programmes involving astronauts.

Dr Foale was sometimes critical of this attitude, and was delighted when the European Space Agency went ahead and selected British Army Air Corps pilot Major Tim Peake as an astronaut candidate, even though the UK government had no direct involvement in the Paris-based organisation's human spaceflight programme.

"Britain's exploration history is huge. It stops somewhere in the middle of the last century and I would like to see it pick up again; and I think Tim represents that," he told the ����ý in 2009.

The UK government's position on space has changed markedly since then, with ministers pumping money into the home industry and even funding activities on the space station.

In addition, the Chancellor George Osborne took the step in June of putting substantial investment behind a design for an air-breathing rocket engine that could one day power a space plane.

Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: