SpaceX launches space station docking port for NASA

SpaceX successfully launched a critical space station docking port for astronauts early Monday, along with a DNA decoder for high-flying genetic research.

As an extra treat, the company brought its leftover first-stage booster back to Cape Canaveral Air Force Station for a vertical landing only the second such land landing for an orbital mission and the ultimate in recycling. Twin sonic booms rocked the moonlit night, old shuttle landing-style.

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Everything got off to a good start as the unmanned Falcon rocket streaked through the middle-of-the-night darkness, carrying 2.3 tonnes of food, experiments and equipment for the International Space Station. The orbiting outpost was soaring over the North Atlantic at liftoff, its six residents asleep.

It was SpaceX's second shot at delivering a new-style docking port for NASA. The last one went up in smoke over the Atlantic last year, a rocket accident casualty.

NASA needs this new docking setup at the International Space Station before Americans can fly there in crew capsules set to debut next year. SpaceX is building astronaut-worthy versions of its Dragon cargo ships, while Boeing which makes these docking ports is working on a crew capsule called Starliner. The pair would dock to this ring and another due to fly in a year.

The Dragon and its latest shipment are due Wednesday at the 400-kilometre-high outpost.

NASA's space station program manager Kirk Shireman expected to be "sweating bullets without a doubt" at liftoff, as always. He said all the cargo is precious, but really wants this docking port "up there safe and sound."

SpaceX, meanwhile, had its sights not only on orbit, but also on the ground.

SpaceX brought its leftover first-stage booster back to Cape Canaveral Air Force Station, just a couple miles from where it lifted off. The company has now pulled off five vertical booster landings since December, three on an ocean platform and two on land. SpaceX employees at company headquarters in Hawthorne, Calif., cheered loudly and applauded when the 15-story booster touched down smoothly.

SpaceX founder and chief executive Elon Musk wants to re-fly his rockets to shave launch costs. The boosters normally are ditched at sea. The company hopes to launch its first recovered rocket this fall.

The station's two Americans will perform a spacewalk in August to hook up the new docking ring, about 1.5 metresacross and one metretall. Another port cobbled together from spare parts will replace the one lost in the June 2015 launch accident.

NASA went with private companies to supply the space station in the wake of the shuttle retirement five years ago this week. The next step will be launching NASA astronauts from U.S. soil; for now, Americans are hitching rides on Russian rockets.