Tim Peake isn't the first Brit in space - that honor went to Helen Sharman , who visited the Russian Mir space station as part of a privately contracted mission over 20 years ago.
And since then, several Brits with dual citizenship have gone into space as part of other countries' space programs, or as part of privately-funded missions.
But on Tuesday, Peake became the first publicly-funded British astronaut to step inside the International Space Station, giving the country its first official representation on ISS.
"The U.K. has taken an understandably hard economic view of human space flight over the years and asked itself what it might be worth," Kevin Fong, an expert in space medicine, told the Associated Press .
Peake docked safely at the space station on Tuesday , along with the Russian Yuri Malenchenko and NASA's Timothy Kopra.
