Lift off: The Orbital Sciences Antares rocket "Cygnus" launches from NASA's Wallops Flight Facility in Wallops Island, Virginia.
A privately-launched supply ship rocketed toward the International Space Station on Thursday following a series of delays.
Orbital Sciences Corp launched its unmanned Antares rocket from Wallops Island, Virginia, carrying a capsule packed with more than 1300 kilograms of equipment and experiments provided by NASA, as well as food and even some ants for an educational project.
Cygnus launches from NASA's Wallops Flight Facility in Wallops Island, Virginia.
The project, which involves about 800 ants in eight separate habitats, aims to study changes in the ants' behaviour in microgravity.
Christmas presents also are on board for the six space station residents; the delivery is a month late.
The spacecraft, named Cygnus, should reach the station on Sunday.
"It's going to be an exciting weekend," Japanese astronaut Koichi Wakata said in a tweet from the space station.
Congratulations on the successful launch of Cygnus spacecraft. It's going to be an exciting weekend of its arrival at the ISS.— Koichi Wakata (@Astro_Wakata) January 9, 2014
Congratulations on the successful launch of Cygnus spacecraft. It's going to be an exciting weekend of its arrival at the ISS.
The delivery had been delayed three times since December, most recently because of a strong solar storm.
Engineers initially feared solar radiation might cause the rocket to veer off course, but additional reviews on Wednesday deemed it an acceptable risk.
Previous delays were due to space station repairs and frigid temperatures.
NASA is paying Orbital Sciences and the SpaceX company to restock the space station.
The Orbital Sciences' contract alone is worth $US1.9 billion ($2.1 billion).
NASA is counting on private industry to keep the space station well stocked and, in another four years, to provide rides to the outpost for US astronauts.
Until then, NASA is forced to buy seats on Russian Soyuz capsules after the retirement of the space shuttles in 2011.
After arriving at the space station, the Cygnus will be unloaded and then filled with rubbish and cut loose for a fiery re-entry in mid-February.
Space station construction began in 1998 and ended with the shuttle program. The White House on Wednesday agreed to a four-year lifetime extension for the station, to 2024.