Nasa says UK astronaut Tim Peake is to help two astronauts carry out a space walk outside the International Space Station.
Tim Kopra and Scott Kelly will go outside to fix a broken part possibly on Monday.
"It will be a very busy and interesting day for Tim," said Libby Jackson from the UK Space Agency.
Tim only arrived at the ISS on Tuesday. He is the first British astronaut to live there.
The space walk is taking place so the astronauts can try to fix a part called the "mobile transporter" - a rail that runs along the length of the space station, which a robotic arm moves along.
Tim, who is living there for about six months will follow the space walk from the inside.
He will get the crew suited and out of the airlock while talking to mission control.
The part became stuck on Wednesday. "The cause of the stall is being evaluated, but experts believe it may be related to a stuck brake handle," said the mission's operations manager, Kenny Todd.
The space walk will be the third for Scott Kelly and the second for Tim Kopra.
Tim Peake's thanked the thousands of people around the world who have sent him good luck messages.
On social media he wrote: "The support for our launch was outstanding, and I want to thank each of you for the #GoodLuckTim messages.
"From the schoolchildren who watched the launch in class, people watching on the underground, and viewers outside of UK, your messages have shown how much interest there is in space and they mean a great deal to me.
"We are very busy up here but I promise to start sharing more of our life in space soon."