Why has a current British national not flown in space with NASA? When I see pictures of all the Shuttle astronauts they have flags of various nations on their sleeves, but never the Union Flag.
Michael Foale (dual citizenship) - 6 shuttle missions
Nicholas Patrick - 2 shuttle missions
Piers Sellers (British born but a US citizen when an astronaut) - 3 shuttle missions
Timothy Peake - was selected but never made it into space
Richard Garriott, while an American citizen, was born in England. When he visited the ISS his coverall carried a logo showing a combined Stars and Stripes and Union Jack.