CAPE CANAVERAL, FLA. —Space E xploration Technologies (SpaceX) is counting on a successful trial run to the international space station early next year to clinch a tightening competition to develop a commercial space taxi for NASA.

With a hoped-for commercial crew budget of $850 million for the fiscal year that began Oct. 1, NASA said it planned to continue development work on two or more space taxi designs, in hopes of breaking Russia’s post-shuttle monopoly on station crew transportation before the end of 2016.

But the agency received $406 million for commercial crew, less than half its request, raising the prospect that either the number of companies funded in the next round of the program would be cut, or the amounts awarded would be insufficient to keep the current schedule. Currently, NASA is investing in four companies: SpaceX, Boeing, Sierra Nevada Corp. and Blue Origin.

“We are still reviewing the budget, its impacts and how we will respond, but meeting our target of having commercial crew capabilities up and running by the middle of this decade is unlikely with the current funding,” Ed Mango, manager of NASA’s Commercial Crew Program at the Kennedy Space Center, wrote in an email to Space News.

NASA planned to release a solicitation for the program’s Integrated Design Contract (IDC) this month. The contract or contracts are slated to begin in July 2012 and conclude in April 2014, a draft request for proposals issued in September shows.

Before selection is made, SpaceX, which debuted its Dragon cargo capsule during a test flight last December, plans to fly a demonstration mission to the station. It also may have flown the first of 12 supply runs already purchased by NASA under a related program.

“I always expected that for the next phase, NASA would down-select from four [companies] to two and that the two would probably be Boeing and SpaceX. Given the lower funding for commercial crew, I’m not sure if NASA still intends to down-select to two or not. If they down-select to one, I think we’ve got a better than even chance of beating Boeing because of the maturity of our spacecraft,” Elon Musk, SpaceX chief executive and chief technical officer, said in an interview with Space News.

“We will have flown to the space station probably twice by the time the commercial crew decision is awarded, and the design of our spacecraft is very similar between cargo and crew, so I think from a risk standpoint, SpaceX is the lowest risk and will be the most proven path to success for commercial crew,” Musk said.

SpaceX currently employs about 1,600 people, including about 70 in Florida. The company is looking for a second launch pad at either Cape Canaveral Air Force Station or one of the space shuttle launch pads at Kennedy, and expects its Florida payroll to include about 1,000 people within four to five years, depending on NASA and other awards.

“I’m highly confident that the commercial space industry will employ more than the government space industry ever did,” Musk said.

The company is awaiting NASA technical reviews for its second demonstration flight, which could include a berthing at the space station.

“From a SpaceX standpoint, we’re ready to go in December, but we have to coordinate that with NASA and any other missions that are going to the space station. What I’ve heard through the grapevine is that NASA is maybe aiming for a February launch,” Musk said. “We’re not going to launch until we’re ready and until NASA thinks we’re ready.”