(CNN) - NASA astronauts Robert Behnken and Douglas Hurley are aboard the SpaceX Crew Dragon capsule and began their 19-hour journey home.
The Crew Dragon spacecraft undocked from its docking port on the International Space Station at 7:36 p.m. (Miami time) on Saturday. The departure of Behnken and Hurley marks the beginning of the final leg of their historic two-month trip to the ISS.
- LOOK: Mars is in fashion, and we tell you why there are so many missions to the red planet
The spacecraft will slowly descend from the International Space Station, which orbits about 402 kilometers above the ground, during the night.
The SpaceX Falcon 9 rocket takes off from the Kennedy Space Center. NASA and space lovers had waited almost a decade for this milestone. The United States has not launched its own astronauts into space since the shuttle program ended in 2011 (SpaceX / Getty Images).
On Sunday afternoon, the Dragon capsule will start its engines as it passes through the thickest parts of Earth's atmosphere. It will then deploy a series of parachutes and is slated to drop off the west coast of Florida on Sunday at 2:42 pm (Miami time).
- MORE: NASA engineer answers your questions about the last mission to Mars
Behnken and Hurley arrived at the ISS in May after they took off from a ground platform in Florida. It was the first launch of NASA astronauts from American soil since 2011 and the first time in history that a commercially developed spacecraft brought humans into orbit.
International Space Station SpaceX