A private space company operated by Internet entrepreneur Elon Musk, has received final clearance from the US Air Force for its debut rocket launch from Florida this weekend.
The company known as SpaceX is set to launch its Falcon 9 rocket between 1 am and 5 am (AEST) on Saturday from its newly refurbished launch pad at Cape Canaveral Air Force Station, just south of the Kennedy Space Center.
Musk, who moonlights as chairman and chief executive of electric car manufacturer Tesla Motors, put the odds of a successful flight at around 75%.
"I think we're probably three-quarters likely to succeed. I hope that fate favours us tomorrow," says Musk.
The company has flown smaller rockets from the Kwajalein Atoll's Omelek Island in the Pacific with mixed success, which Musk says is typical of any new technical system, particularly rocketry.
The Falcon 9's goal is to reach orbit. Typically about half of the first flights of new rockets end short of reaching that mark.
The 55 metre-high, liquid oxygen- and kerosene-fuelled booster will carry a mock-up of a SpaceX capsule known as the Dragon, which NASA plans to use to fly cargo - and perhaps astronauts - to the International Space Station.
NASA is retiring its shuttle fleet after two more flights this year to complete assembly of the station, a US$100 billion (A$ 118 billion) project of 16 nations. No replacement is planned under the NASA budget proposal for the year beginning 1 October, which is pending before Congress.
While NASA shifts its focus to research and technology development, the Obama administration is looking to private firms like SpaceX to pick up NASA's share of the station resupply business. Russia, Europe and Japan fly cargo ships to the station, while Russia operates the only space taxi service for crew members. China, which also has flown people in orbit, is not part of the station partnership.
Rockets for sale
Friday's flight is part of SpaceX's US$400-million (A$472 million) development effort to design and fly discount rockets for governments, companies and research institutes. Of that, US$100 million (A$118 million) came from Musk, co-owner of the PayPal electronic payment system that eBay Inc acquired in 2002 for US$1.5 billion (A$1.67 billion).
SpaceX is selling its Falcon 9 rockets, which can carry 12 tonnes to an orbit about 360 kilometres above Earth, for about US$50 million (A$59 million) - less than half what is typically charged for rides on similar US rockets.
"If the vehicle lifts off the pad, no matter what the outcome is, we're going to learn something that's going to make the second flight more likely and the third flight and the fourth flight," says Ken Bowersox, a SpaceX vice president and former NASA astronaut.
The firm plans to fly up to three Falcon 9/Dragon test missions for NASA, then begin delivering cargo to the space station under a US$1.6 billion (A$1.88 billion) contract next year.
NASA also has a US$1.9 billion (A$2.24 billion) station resupply contract with Orbital Sciences Corp, which plans to debut its Taurus 2 rocket in 2011.