Two NASA astronauts will leave the relative safety of the International Space Station Wednesday in order to service the orbiting laboratory. It will be the 32nd spacewalk performed by US astronauts and the 189th over the life of the ISS, but it will be the first for both of the participants: commander Scott Kelly, who is in the middle of a year-long mission aboard the station, and flight engineer Kjell Lindgren. NASA TV's live coverage will begin at 6:45AM ET, and the spacewalk is scheduled to begin at 8:10AM ET.
While they're outside, Kelly and Lindgren will make a number of upgrades to the station. They'll install a thermal cover on the station's particle physics detector, known as the Alpha Magnetic Spectrometer. They will also service the Canadarm2 robotic arm, which is used to capture SpaceX's Dragon capsules, among other things.
Spacewalks are thrilling to watch (and think about), but they are also slow, laborious affairs. The astronauts are encased in spacewalking suits (or "Extravehicular Mobility Unit," in NASA parlance) that weigh more than 350 pounds. Performing a spacewalk is like taking part in a real-life platformer at excruciatingly low speeds. NASA plans the astronauts movements down to the minute, despite the fact that the missions typically last six, seven, or even eight hours. And even with all that planning, things can still go wrong. In 2013, Italian astronaut Luca Parmitano's helmet started filling with water on an otherwise-routine spacewalk, leading to one of the most terrifying moments in recent ISS history. (He eventually made it back inside safe and sound, but you should read his first-hand account here.)
A NASA animation of the spacewalk plan
Most of the time though, things go exactly as planned. And when that happens, it means space fans are in for a nice long broadcast of (literally) out-of-this-world footage. You can see all that above, courtesy of NASA TV. Also, this spacewalk is just the first of a pair that Kelly and Lindgren will perform. The second one is scheduled for 7:15AM ET on Friday, November 6th.