How will SpaceX’s historic Polaris Dawn private spacewalk work?

Science: Polaris Dawn is set to make history. The SpaceX mission, scheduled to launch Tuesday morning (Aug. 27), will send four people into orbit for five days aboard a Crew Dragon capsule. The quartet will travel farther from Earth than any humans have traveled since the Apollo era — and two of them will carry out the first spacewalk ever performed by a private mission. Here’s a brief overview of what to expect during the epic Polaris Dawn spacewalk, which you’ll be able to watch live via a SpaceX webcast. Day 3 of mission The spacewalk, or extravehicular activity (EVA), will take place on day 3 of the mission — Thursday (Aug. 29). SpaceX and the Polaris Dawn team have not yet announced a target time.

Related: SpaceX Polaris Dawn Crew Lands at Launch Site Ahead of First Private Spacewalk Mission (Photos, Video) The EVA will involve two of the four crew members — commander Jared Isaacman, the billionaire tech entrepreneur who funded and organized Polaris Dawn, and mission specialist Sarah Gillis, an engineer at SpaceX. But the other two astronauts — mission specialist Anna Menon, who is also a SpaceX engineer, and pilot Scott “Kidd” Poteat, a former lieutenant colonel in the U.S. Air Force — will wear their own EVA suits, too. That’s because Crew Dragon doesn’t have an airlock, so the interior of the capsule will be exposed to the vacuum of space. The entire EVA operation — from initial venting to repressurization of the capsule — will take about two hours, Isaacman said during a press conference Monday (Aug. 19).