Space station docking port launched into orbit
SpaceX has successfully launched a docking port into orbit en route to the International Space Station.
The unmanned Falcon rocket streaked upwards through the night sky above Cape Canaveral, Florida, also carrying a range of supplies including food and a new DNA decoder for high-flying genetic research.
As well as the successful take-off, SpaceX was also celebrating after bringing its leftover first-stage booster back to Cape Canaveral Air Force Station for a vertical touchdown - only the second such land landing for an orbital mission and the ultimate in recycling.
Hans Koenigsmann, vice-president of flight reliability for SpaceX, described it as a "really good day".
It was SpaceX's second attempt at delivering a new-style docking port for Nasa. The last one went up in smoke over the Atlantic last year.
Nasa needs the new docking set-up at the 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 the docking ports - is working on a crew capsule called Starliner.
The Dragon and its latest shipment are due to arrive at the space station on Wednesday.
Nasa's space station programme manager Kirk Shireman said he had been "sweating bullets" at lift-off, as Nasa wants the docking port "up there safe and sound" as soon as possible.
SpaceX, meanwhile, had its sights not only on orbit, but also on the ground.
SpaceX brought its leftover first-stage booster back just a couple of miles from where it lifted off eight minutes earlier. The company has now pulled off five vertical booster landings since December, three on an ocean platform and two on land.
Employees at company headquarters in Hawthorne, California, cheered loudly and applauded when the 15-storey booster touched down smoothly.
Mr Koenigsmann said the booster looked to be in "excellent shape and probably pretty soon ready to fly again".
SpaceX founder and chief executive Elon Musk wants to re-fly his rockets to reduce launch costs.
The space station crew will perform a space walk in August to hook up the new docking ring, which is about 5ft across and 3.5ft tall. 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 US soil - for now, Americans are hitching rides on Russian rockets.