SpaceX's Crew Dragon safely delivered two NASA astronauts — Doug Hurley and Bob Behnken — to the International Space Station on Sunday after the company's historic launch Saturday. Why it matters: This marks the first time a private company has delivered people to the space station, and it signals the beginning of the end of NASA's reliance on Russia's Soyuz spacecraft for flights to orbit. Details: Behnken and Hurley docked to the station at 10:16am ET after spending about 19 hours flying through space to catch up to the orbiting outpost. During that flight, the two astronauts ate meals, slept for about eight hours and performed a number of systems checkouts ahead of docking. Behnken and Hurley join NASA's Chris Cassidy and Russian cosmonauts Anatoly Ivanishin and Ivan Vagner aboard the ISS.This mission marks SpaceX's final test flight of its crewed system before it's certified for fully operational missions to the station. The big picture: NASA hopes to continue working with private companies in the future in order to become a buyer of services in low-Earth orbit, opening up the agency to work on getting humans to the Moon and beyond. What's next: The Crew Dragon and its astronauts will stay docked to the space station for at least the next month and could remain in orbit longer, depending on how the capsule performs in orbit. NASA expects the first operational mission will occur in August or September, flying three NASA astronauts and a Japanese astronaut to orbit.Boeing is also partnering with NASA to bring astronauts to the space station. A troubled uncrewed test flight of Boeing's Starliner system is forcing the longtime NASA contractor to redo that test later this year before launching its first crewed mission, which is expected next year.