A cargo ship is en route to the International Space Station, carrying 3,600 lbs. of food, mini-satellites, science equipment, and experimental odor-resistant exercise clothing.

The 133-foot-tall unmanned Orbital Sciences Corp Antares rocket lifted off on Sunday at 12:52 pm Eastern Time, from a commercially operated launch pad at NASA's Wallops Island Flight Facility on the Virginia coast. Perched on top of the rocket was a Cygnus spacecraft, built by Orbital Sciences in partnership with Italy's Thales Alenia Space, a joint venture of Thales SA and Finmeccanica SpA. It is expected to arrive at the space station on Wednesday.

"It's like Christmas in July," said former astronaut Frank Culbertson, an executive vice president at Orbital Sciences.

NASA said the new type of clothing is resistant to bacteria and odor buildup, meaning that the astronauts, each of whom exercise daily in orbit for two hours, won't have to change their clothes as frequently.

Perched on top of the rocket was a Cygnus spacecraft, built by Orbital Sciences in partnership with Italy's Thales Alenia Space, a joint venture of Thales SA and Finmeccanica SpA.

The mission is the second of eight station cargo runs by Orbital Sciences under a $1.9 billion contract with NASA. The space agency hired two companies — Orbital Sciences and SpaceX — to make deliveries to the space station. The international partners also make shipments; the European Space Agency, for example, will launch its final supply ship from French Guiana late next week.

This particular Cygnus delivery was delayed a few months by various problems, including additional engine inspections and, most recently, bad weather at the Wallops Island launch site.

The Cygnus will remain at the space station for about a month. It will be filled with trash, cut loose from the space station, and redirected into the atmosphere for incineration.. Unlike the SpaceX Dragon capsule, the Cygnus is not built to return safely to Earth.

Saturday, meanwhile, marked the 5,000th day of continuous human habitation at the 260-mile-high outpost. Six men currently are on board, representing the United States, Russia and Germany.

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"Humans are explorers!" German astronaut Alexander Gerst said via Twitter.

Information from Reuters and the Associated Press was used in this report.