Tim Peake has apologized in a Twitter post after dialing a wrong number from space.
He said to a woman on the other end of the line: “Hello, is this planet Earth?”
The British astronaut tweeted: “I’d like to apologize to the lady I just called by mistake saying <<Hello, is this planet Earth?>> – not a prank call… just a wrong number!”
The British astronaut, a father-of-two from Chichester, West Sussex, arrived at the International Space Station (ISS) on Tuesday, December 15.
Tim Peake, 43, is spending six months conducting scientific experiments on the station.
Earlier in the week, he helped two fellow crew members to conduct a space walk outside the ISS.
NASA astronauts Tim Kopra and Scott Kelly went outside the ISS to fix a broken component.
Tim Peake, who is a former major in the Army, is the first Briton to join the crew of the ISS and is employed by the European Space Agency (ESA).
Helen Sharman became the first British citizen to travel to space when she visited the Soviet Mir orbiting station in 1991.
Other Britons who have flown into space have done so either as private individuals or by taking US citizenship.
Tim Peake, 43, was waved off by his wife and two sons, Thomas, 6, and Oliver, 4, at the Baikonur Cosmodrome in Kazakhstan.