SpaceX

Therefore, Boeing's Starliner spacecraft will undock from the station early next month—the tentative date, according to a source, is September 6—and attempt to make an autonomous return to Earth and land in a desert in the southwestern United States.

Then, no earlier than September 24, a Crew Dragon spacecraft will launch with two astronauts (NASA has not named the two crew members yet) to the space station with two empty seats. Wilmore and Williams will join these two Crew-9 astronauts for their previously scheduled six-month increment on the space station. All four will then return to Earth on the Crew Dragon vehicle.