The Falcon 9 rocket and Crew Dragon capsule Resilience lifted off into a partly cloudy, dark sky at 7:27 p.m. EST from Kennedy Space Center.
The launch began a 27½-hour journey through space to the orbiting platform, which passed over the launch site just before liftoff. The astronauts planned to sleep aboard the spacecraft, which is about 27 feet tall including an attached storage trunk.
Unlike this year’s previous Crew Dragon mission, the astronauts who headed to space on Sunday did not plan to perform any navigation of the self-guided capsule unless necessary, according to NASA.
The rocket’s first-stage booster landed successfully on a barge in the Atlantic Ocean a little over 9 minutes after liftoff. SpaceX intends to use that booster to launch the next astronaut crew to the space station in spring 2021.
Live video from inside the capsule showed the four astronauts safely ensconced in their SpaceX spacesuits and chairs. After about 12 minutes, the capsule separated from the rocket’s second stage and flew independently.
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Astronauts had said earlier in the week they were eager to fly.
“As a crew, we are ready. We are ready for this launch,” astronaut Mike Hopkins, spacecraft commander, said in a press conference last week. “We are ready for the six months of work that is waiting for us on board the International Space Station, and we are ready for the return.”
The flight marks the first SpaceX crewed mission considered to be operational after NASA certified the rocket and capsule for regular missions last week. Two astronauts, Bob Behnken and Doug Hurley, flew with SpaceX in a two-month demonstration mission to the space station this summer.
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The mission also is the first routine flight to the space station under NASA’s Commercial Crew Program, in which the space agency contracts to use spacecraft developed and owned by private companies, namely SpaceX and Boeing.
President George W. Bush’s administration proposed the program and President Barack Obama’s administration began it. On Sunday, Vice President Mike Pence and his wife, Karen, traveled to Florida to watch that plan advance during a visit to Kennedy Space Center for the launch.