Tamed Dragon: Cargo Space Ship And ISS Link Up

A commercial cargo spacecraft, delivering a ton of supplies, has successfully docked with the International Space Station after a shaky start to its mission.

The station's astronauts used a robotic arm to capture the Dragon, owned by the SpaceX company, about 240 miles above the earth, over Ukraine.

Nasa is paying the California-based firm $1.6bn (£1bn) for a series of supply runs to the manned outpost. This is the second of 12.

SpaceX launched the cargo ship into orbit on Friday and quickly ran into trouble.

A clogged pressure line or stuck valve kept the thrusters, or small manoeuvering rockets, from working.

Flight controllers finally got the thrusters up and managed to salvage the supply mission.

The Dragon's arrival was just one day late.

In the end, the Dragon approached the orbiting lab with its one-ton load about as smoothly as could be expected, with all of its thrusters operating perfectly.

"As they say, it's not where you start, but where you finish that counts," said space station commander Kevin Ford, "and you guys really finished this one on the mark".

He added: "We've got lots of science on there to bring aboard and get done. So congratulations to all of you."

Among the items on board: 640 seeds of a flowering weed used for research, mouse stem cells, food and clothes for the six men on board the space station, trash bags, computer equipment, air purifiers, spacewalking tools and batteries.

The Dragon will remain at the space station for most of March before returning to Earth with science samples, empty food containers and old equipment.