Astronauts Suni Williams and Butch Wilmore, who have been stranded at the International Space Station for nine months, will finally return to Earth on Tuesday, one day earlier than expected.

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.