WASHINGTON — When privately operated spacecraft begin ferrying NASA astronauts to the international space station, the Federal Aviation Administration (FAA) will license launch and re-entry but leave it to NASA to decide whether the vehicles are fit to dock with the station and carry astronauts in the first place, the heads of the two agencies said June 18 in a joint press briefing.

NASA and FAA held the briefing to discuss a memorandum of understanding (MOU) they signed June 4. The document lays the foundation for developing the federal regulations that will govern crewed flights of privately operated spacecraft.

“This MOU is intended to support the transition to commercial transport of government and non-government passengers to low-Earth orbit in a manner that avoids conflicting requirements and multiple sets of standards,” the document states.

The FAA’s Office of Commercial Space Transportation is the licensing and permitting body for all U.S. commercial space transportation.

“On the FAA side, the licensing requirements and our assurance of public safety is the same whether it’s a NASA mission or a pure commercial mission,” acting FAA Administrator Michael Huerta said. “It’s all just to maintain the safe environment during launch and re-entry.”

NASA Administrator Charles Bolden said NASA will have no jurisdiction over commercial human space transportation unless the vehicles are carrying NASA personnel or visiting NASA destinations, such as the space station.

“The FAA is always involved,” Bolden said during the briefing. “NASA is only involved when there is a NASA fee being paid for the service because there are NASA crew members aboard.”

The first privately operated, passenger-carrying spacecraft likely to reach orbit are being developed in part with NASA funding for the purpose of getting NASA astronauts to and from the international space station.

At least four companies are vying for funding under the third round of NASA’s Commercial Crew Program: ATK Aerospace, Magna, Utah; Boeing Space Exploration, Houston; Sierra Nevada Space Systems, Louisville, Colo.; and Space Exploration Technologies Corp., Hawthorne, Calif.

The companies are competing for awards worth $300 million to $500 million apiece over a 21-month technology development period. NASA’s goal is to get designs for at least two competing systems, including a crew vehicle and a launcher, ready to enter production in time to begin crewed flights by 2017. The agency will pick three winners around mid-July, Bolden said during the teleconference.

One of those three will be funded at half the level of the other two winners, Bolden said.

“Two companies will get full funding at whatever level is decided based upon the amount in the NASA appropriation for commercial crew,” Bolden said. “The third company would get about half of that.”

This arrangement is part of a compromise NASA reached with Rep. Frank Wolf, chairman of the House Appropriations commerce, justice, science subcommittee, as a condition of Wolf dropping his insistence that NASA immediately pick a single company to build an astronaut taxi system.

Although only three companies will be eligible for funding, NASA wants to keep “upwards of three companies” involved in the third round of the Commercial Crew Program, which is known as the Commercial Crew Integrated Capability phase.

In the Commercial Crew Program’s previous round, which is set to wrap up in August, NASA gave financial assistance to four companies working on crewed spacecraft. Three other companies, however, got unfunded Space Act Agreements. The latter type of agreement provides access to NASA facilities, documents and technical expertise, but no NASA funding.

The Commercial Crew Program has encountered resistance from congressional appropriators, who have yet to allocate anything close to the more than $800 million in annual funding the White House has sought for the past two years. The program got $406 million last year. This year, spending bills in the House and Senate provide $500 million and $525 million, respectively, for 2013. Wolf has agreed to fund the program at the Senate-approved level, but that will not become official until lawmakers in both chambers gather in conference to iron out the differences in the two spending bills.

While Bolden praised the compromise, he once again warned that the Commercial Crew Program will need more cash soon to meet its goal of producing a domestic astronaut transportation system by 2017. He said NASA will seek a “significant increase” in commercial crew funds in 2014.

“Ideally, I would say that what we want is to see the president’s [2013] request, which was the $850 million,” Bolden said during the briefing.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.