The White House is requesting a $17.5 billion budget for the U.S. space agency in the fiscal year that begins Oct. 1.

That marks a 1 percent decrease from NASA's 2014 budget. But NASA could also have access to an additional $900 million from Obama's proposed Opportunity, Growth and Security Initiative, a $56 billion fund for special projects that is separate from the regular budget.

If approved, the agency would have $1.1 billion next year to help at least two companies develop commercial space taxis to fly astronauts to and from the space station. The $100 billion research outpost, a project of 15 nations, flies about 260 miles (420 km) above Earth.

Since the space shuttles were retired in 2011, the United States is dependent on Russia to fly crews to the space station at a cost of more than $65 million a seat.