SpaceX just docked the first commercial spaceship built for astronauts to the International Space Station ? what NASA calls a 'historic achievement'

"A new generation of space flight starts now with the arrival of @SpaceX's Crew Dragon to the @Space_Station," Jim Bridenstine, NASA's administrator, tweeted on Sunday. "Congratulations to all for this historic achievement getting us closer to flying American Astronauts on American rockets." Read more: NASA picked these 9 astronauts to fly SpaceX and Boeing's spaceships for the first timeThe astronauts of Expedition 58 at the International Space Station speak during a welcome ceremony for SpaceX's Crew Dragon capsule, the first commercial spaceship to enter orbit, on March 3, 2019. This is a good day, a first day of a new era for the next generation of space explorers." Astronaut Anne McClain plays with a plush Earth toy inside SpaceX's Crew Dragon capsule. SpaceX founder Elon Musk (left), NASA astronauts Victor Glover, Doug Hurley, Bob Behnken, NASA Administrator Jim Bridenstine, and NASA astronaut Mike Hopkins are seen inside the crew access arm with the SpaceX Crew Dragon spacecraft visible behind them during a tour of Launch Complex 39A before the early Saturday morning launch of the Demo-1 mission, Friday, March 1, 2019 at the Kennedy Space Center in Florida.Joel Kowsky/NASA "The whole goal of SpaceX was crewed spaceflight, and improving space exploration technologies — that's actually the full name of the company: Space Exploration Technologies," Musk said during a press briefing on Saturday after launch.