Orbital Sciences Cygnus cargo ship reaches International Space Station

This picture provided by NASA shows the Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft onboard, at sunrise on July 12, 2014 on launch Pad-0A at NASA's Wallops Flight Facility in Virginia

Orbital Sciences Corporation's unmanned cargo ship arrived Wednesday at the International Space Station carrying a load of food and equipment for the six-man crew at the research outpost.

The vessel called Cygnus was grabbed by the space station's robotic arm at 6:36 am (1036 GMT) and completed the berthing procedure that attached the spaceship to the ISS at 1253 GMT, NASA said.

"Cygnus is now hard-mated to the International Space Station's Harmony module," where it will stay for the next four weeks, a commentator said on NASA's live broadcast of the event.

The spacecraft, which is shaped like a giant beer keg, launched from Wallops Island, Virginia on Sunday atop an Antares rocket.

Astronauts are scheduled to open the hatch on Thursday, but they may do so as early as Wednesday if the work of bolting the cargo ship to the orbiting lab goes faster than planned.

The spacecraft is packed with 3,653 pounds (1,657 kilograms) of gear for the space station.

Much of the load is prepackaged food for the crew, but the cargo also contains Earth-imaging satellites, experiments for growing arugula in space and a pump for the Japanese module to replace one that failed.

The mission, known as Orb-2, is the second of eight that Orbital has contracted with NASA, and is the third journey by a Cygnus to the International Space Station after a successful demonstration trip last year.

Orbital Sciences and SpaceX are the two private US companies that have won major contracts with NASA for multiple missions to carry supplies to the International Space Station.

Orbital's deal is worth $1.9 billion and SpaceX's contract is for $1.6 billion.