SpaceX's new crew capsule aces space station docking

SpaceX's sleek, new crew capsule arrived at the International Space Station, acing its second milestone in just over a day. No one was aboard the Dragon capsule launched Saturday on its first test flight, only an instrumented dummy. But that quickly changed once the hatch swung open and the space station astronauts floated inside.

This beefed-up, redesigned Dragon is the first American-made, designed-for-crew spacecraft to pull up to the station in eight years. The next one coming up will have its own two-man crew.

"A new generation of space flight starts now with the arrival of @SpaceX's Crew Dragon to the @Space_Station," NASA Administrator Jim Bridenstine tweeted.

The space station's three astronauts had front-row seats as the white 27-foot-long (8-meter-long) capsule neatly docked. Two hours later, the station crew entered to take air samples, wear oxygen masks and hoods until getting the all-clear.

If the six-day demo goes well, SpaceX could launch two astronauts this summer under NASA's commercial crew program. Both astronauts Doug Hurley and Bob Behnken were at SpaceX Mission Control in Southern California, watching all the action. They rushed there from Florida after the Dragon rocketed into orbit early Saturday from NASA's Kennedy Space Centre.

"Just super excited to see it," Behnken said minutes after the link-up. "Just one more milestone that gets us ready for our flight coming up here." Dragon will remain at the space station until Friday, when it undocks and aims for a splashdown in the Atlantic, a couple hundred miles off the Florida coast.

While the private SpaceX has sent plenty of its Dragon capsules filled with cargo to the space station for NASA, crew Dragon is a different beast. It docked on its own, instead of relying on the station's robot arm for berthing. The capsule's nose cap was wide open like a dragon's mouth, to expose the docking mechanism.

Behnken said that's the way it should work when he and Hurley are on board; they may push a button or two and will have the ability to intervene, if necessary.

As part of Sunday's shakedown, the station astronauts sent commands for the Dragon to retreat and then move forward again, before the capsule closed in for good.

SpaceX employees at company headquarters in Hawthorne, California, cheered and applauded as crew Dragon pulled up and docked at the orbiting lab, nearly 260 miles (400 kilometres) above the Pacific, north of New Zealand.

The capsule's lone passenger for launch a mannequin wearing a white SpaceX spacesuit remained strapped into its seat as the station's U.S., Canadian and Russian crew removed supplies and photographed the spotless white interior. The test dummy or Smarty as SpaceX likes to call it is named Ripley after the lead character in the science-fiction "Alien" films.

Like Ripley, the capsule is rigged with sensors to measure noise, vibration and stresses, and to monitor the life-support, propulsion and other critical systems throughout the flight.

SpaceX aims to launch Behnken and Hurley as early as July. Next up should be Boeing, NASA's other commercial crew provider. Boeing is looking to launch its Starliner capsule without a crew as early as April and with a crew possibly in August.

NASA is paying the two private companies $8 billion to build and operate the capsules for ferrying astronauts to and from the space station. Astronauts have been stuck riding Russian rockets ever since NASA's space shuttle program ended in 2011. Russian Soyuz seats go for up to USD 82 million apiece.