American astronauts could be barred from Russia’s Gagarin Cosmonaut Training Center starting this spring until the United States guarantees that it will pay for Soyuz flights to the international space station once Russia’s treaty obligations to provide those flights expires early next year.

A U.S.-Russian agreement secures American astronauts a seat aboard the Soyuz spacecraft that ferry crews to the international space station and ensures their safe return in an emergency. However, that deal expires in early 2006. While Russia is willing to continue providing Soyuz spacecraft for the international space station after that, Russian officials have made it clear they expect to be paid for those flights and for the mandatory crew training that occurs before each Soyuz mission to the space station.

Russia wants the United States to pay for use of the Soyuz starting in April 2006, but a U.S. law enacted to curb outside assistance to Iran’s weapons programs also bars NASA from paying Russia for any space station-related goods or services.

NASA officials acknowledge the United States needs the Russian Soyuz if it wants American astronauts to participate in extended stays on board the space station in 2006 and beyond. But they also acknowledge that the Iran Nonproliferation Act (INA) of 2000 is a significant barrier to direct payments for the Soyuz spacecraft services Russia now provides as part of its obligation to other nations in the international space station partnership.

A central provision of the law prohibits NASA from making space station-related payments to Russia unless the president assures Congress that Russian industry has stopped helping Iran with its efforts to field ballistic missiles and other advanced weaponry.

The Bush administration and some members of Congress have been talking for months about possible remedies to the situation, but the White House has yet to make public what, if anything, it intends to do.

With two American astronauts needing to begin the Russian-led part of their training this spring if either of them are to fly to the space station next April as part of the Expedition 13 crew, Russia is insisting on at least a sign that the United States is making progress on the INA issues before the training begins, according to Russian and U.S. familiar with the ongoing negotiations.

“They don’t have to have the money or even a solution by April but they have to show that progress is being made,” said a Washington space policy analyst familiar with the situation.

That also is the word from Russia. A senior manager in the Russian space industry told Space News in a March 18 interview that the Russian space agency is not insisting on an upfront payment for training, but rather a guarantee that it will be paid. In the meantime, the senior manager said, the Gagarin center has been instructed not to accept any astronauts for training beyond Expedition 12 until the “issue of payment is resolved.”

U.S. and Russian space agency officials either declined comment or would say only that negotiations were still underway. A spokesman for the Gagarin center, Sergei Kovrov, declined to comment on whether Americans would be turned away.

NASA spokeswoman Debra Rahn said that any astronaut the United States would want to send to the space station in April 2006 aboard a Soyuz “would need to start training in earnest in the next one to two months” at the Gagarin center.

She said the training of U.S. astronauts is part of the ongoing negotiations, but would not say whether Russia needs proof of progress on a solution to the Soyuz problem before it will train an American for the April 2006 flight.

“The subject of the Russians training U.S. astronauts for Expedition 13 is part of our discussions with the Russians on the balance of contributions, and we do not comment on ongoing negotiations,” Rahn said March 25.

The Iran Nonproliferation Act is a delicate subject in official Washington. Since the law was enacted in 2000, U.S. relations with Iran have only deteriorated, and policy analysts and congressional sources agree that tackling the problems the INA creates for NASA entails political risk for a White House that recently has stepped up its rhetoric on the need to curb proliferation.

A report from the Congressional Research Service published in March warned that while it is unlikely U.S. President George W. Bush would determine that Russia is complying with the INA, it may be equally unlikely that the law would be repealed or amended given the current political atmosphere. “Iran’s nuclear program at present is an urgent concern,” the report notes.

The Congressional Research Service does not make recommendations, but does raise questions about whether extended U.S. stays aboard the space station are necessary to support the goals of NASA’s new long-term space exploration vision.

“From a space program perspective, the threshold question is the extent to which NASA needs to have U.S. astronauts on the [space station] or long duration missions between 2006 and 2010, and to have any astronauts there after 2010,” the report says. “Under the Vision, the only U.S. research that will be conducted on the [space station] is that needed to support the Vision. Questions thus arise as to whether adequate research could be performed on Earth (and, eventually, the Moon), or if NASA could pay astronauts from the non-Russian [space station] partners to conduct the research.”

Brian Berger is editor in chief of and the SpaceNews magazine. He joined in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...