WASHINGTON — NASA is banking on its Commercial Crew Program to increase international space station (ISS) crew capacity to seven from the current six — something that could happen as soon as 2017 if Congress is willing to dramatically increase the program’s budget, the agency’s top human spaceflight official said.

“We would definitely increase the crew size on ISS to seven crew members,” William Gerstenmaier, associate administrator for NASA’s Human Exploration and Operations Mission Directorate, said June 20 during a hearing before the Senate Commerce science and space subcommittee. “We think that will increase the research capability onboard station and allow us to do more national lab research and be more effective in utilizing space station.”

To do that, and to ensure that the privately operated astronaut taxis NASA is helping industry develop are flying by 2017, the Commercial Crew Program will need more than $800 million in annual funding from 2014 to 2017. Congress gave the program $406 million for 2012, less than half what NASA requested. The program is poised to fare somewhat better in 2013, with key lawmakers pledging $525 million of the $830 million the agency requested.

NASA currently pays the Russian space agency, Roscosmos, about $60 million a seat to ferry crew members to the international space station aboard Soyuz spacecraft. The U.S. companies competing to develop a domestic alternative to Soyuz are expected to beat that price, Gerstenmaier said.

“We expect there to be a cost reduction, but I think it’s a little too early for us to pick a particular value for a cost reduction,” Gerstenmaier said. He added that NASA plans to buy seats on two commercial crew flights a year. The agency would book four seats on each flight, he said.

Congress and the White House have frequently disagreed about how to run the Commercial Crew Program. Earlier this year, Rep. Frank Wolf (R-Va.), chairman of the House Appropriations commerce, justice, science subcommittee, drafted legislation calling for NASA to immediately pick a single provider to build a crew transportation system rather than prolong competition with multiple large awards.

Wolf announced June 5 that he had dropped that demand after NASA agreed to fund no more than three providers, one of which would get half as much funding as the others. Wolf also insisted that the agency shift away from funded Space Act Agreements to more traditional government contracts once the next 21-month phase of the program concludes.

Awards for the Commercial Crew Integrated Capability phase are on track for mid-July, NASA Administrator Charles Bolden said June 18. At least four companies are competing for an award: ATK Aerospace, Magna, Utah; Boeing Space Exploration, Houston; Sierra Nevada Space Systems, Louisville, Colo.; and Space Exploration Technologies Corp., Hawthorne, Calif.

Meanwhile, an industry witness at the June 20 hearing said space transportation prices will have to fall substantially before any business plan involving a payload — crew or cargo — becomes palatable to private enterprise.

“Those prices must come down from the 60-plus-million-dollar range,” said Mike Gold, director of Washington operations and business growth for Bigelow Aerospace, North Las Vegas, Nev. “They must come down dramatically for there to be a business case from the private sector.”

Bigelow is developing inflatable space habitats that it wants to market primarily to foreign governments. The company has sent two prototype modules into space on Russian rockets but says it cannot afford to develop or fly an operational habitat until cheaper space transportation is available. Gold said Bigelow needs a domestic transportation option because U.S. export control policies carry their own costs. Bigelow spent about $1 million on export control compliance for the two Russian launches it bought.

Michael Lopez-Alegria, president of the Commercial Spaceflight Federation here, told lawmakers that the companies developing commercial crew taxis are counting on ISS service contracts to make their business cases close.

“We sort of need the [international space station] to be there for us,” Lopez-Alegria said. “We support whatever is necessary to ensure future use of the space station.”

Lopez-Alegria called on Congress to renew NASA’s waiver to provisions in the Iran, North Korea and Syria Nonproliferation Act that bar the agency from buying space station-related goods and services from Russia. The current waiver expires in 2016 and, in addition to letting NASA buy Soyuz seats, allows the agency to barter with Russia for engineering and data analysis critical to keeping the station operational.

Gerstenmaier said without a new waiver, the United States will have to depend on Russian goodwill to secure needed engineering services.

“Maybe they would donate that engineering service and that research service without bartering for it, I don’t know if that’s the case or not,” Gerstenmaier said.

Sen. Bill Nelson (D-Fla.), chairman of the Senate Commerce science and space subcommittee, offered strong support for granting such a waiver.

“We don’t have any choice, we have to pass that,” Nelson said at the hearing. “We simply can’t let that get in the way of us moving ahead with the space program.” He did not say whether the waiver would appear as stand-alone legislation or as part of another bill.

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.