After their weeklong journey turned into a monthslong stay on the International Space Station, two Boeing Starliner astronauts will soon be united with the spacecraft that will eventually bring them home.

In a significant milestone for space travel, the SpaceX crew tasked with bringing back two astronauts stranded on the International Space Station (ISS) successfully docked with the orbiting laboratory on Sunday,

The Crew-9 incident was the second Falcon 9 upper-stage issue to crop up in less than three months. On July 11, the rocket experienced a leak of liquid oxygen in its upper stage during the launch of 20 of SpaceX's Starlink internet satellites. As a result, the spacecraft were deployed too low and ended up being lost.

The SpaceX Crew-9 Dragon will dock at the International Space Station Sunday afternoon. After a successful launch on Saturday, the two-man crew will be docking at the ISS. The Dargon spacecraft, which is supporting this mission, previously flew the Crew-4, Ax-2, and Ax-3 missions to and from the International Space Station.

The SpaceX capsule will eventually bring home Butch Wilmore and Suni Williams, the NASA astronauts who piloted the Boeing Starliner test flight.

In that incident, the FAA grounded Falcon 9 for two weeks when the video feed of a launch from California on July 11 showed the second stage’s engine freezing over in space. It resulted in SpaceX not being able to put its payloads into a correct orbit.

The Dragon Crew 9 capsule has docked with the International Space Station, carrying a U.S. astronaut and a Russian cosmonaut. The craft will bring home two astronauts stranded on the International Space Station.

A SpaceX Crew Dragon spacecraft caught up with the International Space Station and moved in for docking Sunday.

A SpaceX Crew Dragon space capsule, which is due to bring home stuck astronauts Butch Wilmore and Suni Williams next year, arrived at the International Space Station (ISS) on Sunday, according to NASA and SpaceX.