Ground control to Major Tim.
British Astronaut Tim Peake -- who is a retired major in the British Army -- is taking part in his first-ever spacewalk today, alongside NASA's Tim Kopra.
The two Tims spent the morning outside the International Space Station fixing a voltage regulator, which caused an outage to one of the station's eight power channels last fall. The two astronauts are now spending the remainder of the planned six-and-a-half hour walk routing cables, which will support the docking of future NASA commercial crew vehicles.
Peake, who arrived at the space station last month, is part of a six-month mission and has the distinction of being the first British astronaut to live at the International Space Station -- and the first to take a space walk.
Before stepping outside today, Peake reflected on his years of training for an EVA -- that's short for extravehicular activity, what astronauts call a space walk -- and the work ahead.
"To undertake an EVA takes several years of training. We have spent many hours working in our spacesuits, ‘floating’ in the largest swimming pool on Earth with a Space Station mockup," he wrote in a blog post. "We have used virtual reality headsets to re-enact our operations and trained for the worst case scenario of becoming detached from the Space Station.
For this particular space walk, Peake said he had spent months training on Earth and in space, reviewing the 40-page timeline he and Kopra will be walked through from ground control, along with making sure their space suits and tools were ready for the job.
And as he points out -- in true "The Martian" fashion -- Peake is even taking a toothbrush with him on his space walk. The reason: It can be fabricated into a makeshift tool, if necessary, to clean debris out of a part of the space station that doesn't always turn smoothly.