Two astronauts are one step closer to returning to Earth. A SpaceX Dragon carrying a crew of four will dock at the International Space Station later tonight. The crew will replace Butch Wilmore and Suni Williams, who have been in space for more than nine months.

NASA plans to provide live coverage of both the undocking process and the ship's reentry into Earth's atmosphere through landing. People at home can watch the hatch closing with a broadcast that begins at 10:45 p.m. ET on March 17. Undocking will roll into the next day at 12:45 a.m. on March 18 .