Two astronauts based at the International Space Station (ISS) are currently walking in space. Wearing their astronaut suits, they have exited their spacecraft are now floating around, gravity-free.
The purpose of their space walk is to mend a key component of the ISS' machinery, the mobile transporter, a rail car that moves a robotic arm along the length of the station. It's been stuck since Wednesday last week, and the team needs to sort it out before a cargo supply ship arrives in two days.
The pair – flight engineer Tim Kopra and commander Scott Kelly – are working for Nasa, and are expected to be spacewalking for between three and three and a half hours, from 1.10pm onwards. You can watch the walk live on Nasa TV here:
Also based at the station, although not involved in today's walk, is British astronaut Tim Peake. After travelling up to the ISS on Tuesday last week, he has now begun his six month mission, which will focus on scientific experiments.
He's not the first British person to go into space, but he is the only British astronaut to ever be selected by the European Space Agency for a mission. Technically, this makes him the UK's first ever official astronaut.
He may not be going into space today, but he is providing assistance, along with Russian astronaut Sergey Volkov. Their duties include getting the crew into their suits and out of airlock, while also interacting with mission control.