From NPR.

Later today, a SpaceX capsule is scheduled to carry four astronauts to the International Space Station. Their arrival will clear the way for two astronauts that have been labeled as "stranded" to finally return to Earth.

The astronauts, Butch Wilmore and Suni Williams, were supposed to spend about a week on the space station when they went up last June. But they remained on the ISS after the experimental Boeing capsule they took into orbit malfunctioned.

In the past month, President Trump and his close adviser Elon Musk have repeatedly claimed that the decision to leave Williams and Wilmore in space was politically motivated. But some former astronauts and NASA officials have denied any political motives behind the extended stay of Williams and Wilmore.