Orbital's Cygnus Cargo Craft Arrives at International Space Station

Orbital Sciences' Cygnus cargo craft arrived at the International Space Station early Sunday morning as part of the company's first resupply mission following a successful test run last September.

NASA crew member Mike Hopkins used the station's Canadarm2 to grapple Cygnus at 6:08 a.m. EST, more than two days after the cargo craft was launched into space aboard Orbital's Antares rocket.

Japan's Koichi Wakata guided Cygnus to the Harmony node where it berthed two hours later. Rick Mastracchio, also from NASA, led the bolting and latching of the craft before he and Hopkins opened the craft's hatch just after noon.

The cargo craft arrived on time at the station despite the launch being delayed a day due to an X1.2-class solar flare and its associated Earth-directed coronal mass ejection. In classifying solar flares, both the letter and number relate to strength, with X being the strongest and an X2 being twice as strong as an X1. While the radiation they produce is unable to make its way through the Earth's atmosphere to harm humans, launch officials expressed concern regarding the particles' effects on the rocket's electronic systems.

The hold up came after weeks of delays that began when a pump module on one of the station's two external cooling pipes automatically shut down Dec. 11 upon reaching its preset temperature limit. Two spacewalks followed - one to remove the faulty module and a second to replace it. Both were performed by Hopkins and Mastracchio, who finished up Dec. 25 after more than 7 hours outside the space station.

Cygnus brought with it almost 3,000 pounds of cargo, including science equipment, crew provisions and 23 student projects. Once its job at the station is completed, the cargo ship will be unberthed and abandoned ahead of its fiery end over the Pacific Ocean on Feb. 19. Once this happens, Orbital will have completed its first mission as part of a nearly $2 billion contract with NASA.