SpaceX capsule arrives at International Space Station

A privately-owned unmanned US space capsule arrived at the International Space Station on Sunday, bringing to the space outpost food, scientific materials and other crucial equipment.

The capsule named Dragon was captured – with the help of a robotic arm – by Nasa Expedition 34 Commander Kevin Ford and Flight Engineer Tom Marshburn, when the ISS was over northern Ukraine, US space officials said.

The craft, owned by SpaceX corporation, will now be inspected via cameras, brought to the earth-facing port of the ISS’s Harmony module and bolted into place by commands from mission control.

The original plan was for Dragon to attach to the space station on Saturday and return to earth on March 25, splashing down in the Pacific Ocean off Mexico’s Baja California peninsula.

But the capsule ran into troubles with its thrusters shortly after launching on Friday from Cape Canaveral, Florida, triggering the delay.

SpaceX engineers found that only one of the spacecraft’s four thruster pods, which help manoeuvre the capsule in orbit, was working. The problems were later fixed.

The delay, however, will not affect the capsule’s splashdown, which remains planned for March 25, the US space agency said.

Dragon is carrying 544kg of supplies on SpaceX’s second resupply mission to the ISS.

This is the third commercial mission by SpaceX – Space Exploration Technologies – to the orbiting space station under contract with Nasa.

In May last year, SpaceX made history when Dragon became the first commercial spacecraft in history to successfully attach to the International Space Station.

Previously only four governments – the United States, Russia, Japan and the European Space Agency – had achieved this challenging technical feat.

SpaceX has now begun regular missions to the space station, completing its first official resupply mission in October.

Nasa is relying on SpaceX and other commercial ventures to take over for its retired fleet of space shuttles, which last flew in July 2011.

Before SpaceX’s successful mission in October, Nasa had been relying on Russian spacecraft – but the Soyuz craft does not have room for cargo on the return flight.

SpaceX says it has 50 launches planned – both Nasa missions and commercial flights – totalling about US$4 billion in contracts.

So far, SpaceX has only sent unmanned flights into orbit, but the company aims to send a manned flight within the next three or four years. It is under a separate contract with Nasa to refine the capsule so that it can carry a crew.

Nasa also has a US$1.9 billion resupply contract for the station with Orbital Sciences Corporation, which will launch the first test flight of its Antares rocket from a base in Virginia in the coming weeks.

The cargo for the 25-day mission includes equipment for 160 experiments to be conducted by the space station crew, which currently consists of two Americans, three Russians and a Canadian.