On Sunday night, SpaceX will attempt to launch another Dragon capsule full of food, clothes and science experiments for the astronauts at the space station. The company hopes to repeat the success of its test flight in May.
Rainy weather could keep the company's Falcon rocket grounded. Forecasters said Thursday there's a 60 percent chance of favorable conditions for the 8:35 p.m. launch from Cape Canaveral.
This is the California company's first official launch under a $1.6 billion contract with NASA. The contract calls for 12 deliveries.
The Dragon will spend a few weeks at the space station before being cut loose at the end of October with a full load of science experiments and old equipment. It will parachute into the Pacific.
Among the items going up and coming back on the Dragon are a dozen student experiments that flew aboard the SpaceX capsule in May, but were not properly activated by the station crew. NASA offered this second chance.
NASA is counting on private business to help keep the space station stocked, now that the shuttles are retired. The governments of Russia, Japan and Europe also provide periodic supply runs.
A second company, the Virginia-based Orbital Sciences Corp., hopes to launch its Antares rocket with a mockup capsule by the end of this year, out of Wallops Island. The first test flight to the space station, by Orbital Sciences, is targeted for early 2013.
SpaceX -- or Space Exploration Technologies Corp. -- is run by PayPal co-founder Elon Musk, who's also the chief executive officer of the electric car-maker, Tesla Motors. He is working to modify the Dragon capsule in order to carry astronauts back and forth to the space station, within three to five years. Americans currently hitch rides on Russian rockets.