The House yesterday passed a bill to allow U.S. astronauts to fly on Russian Soyuz spacecraft through the end of 2011 in a move to forestall the possibility that the United States would lose access to the international space station.

The legislation amends the Iran Nonproliferation Act of 2000 that prohibits the use of most Russian space technology and know-how as long as Russia is exporting nuclear and missile technology to Iran.

The House unanimously approved the bill, a modified version of legislation drafted by Senate Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.) and passed by the Senate last month.

Lugar's office said it is confident that the Senate will quickly pass the House version and that President Bush, despite some early misgivings, is prepared to sign it.

"A lot of folks in NASA and across the Bush administration have been working on this for a long time," NASA spokesman David Mould said earlier. "We're looking forward to it passing."

The amendment enables the United States to escape the consequences of a Republican-inspired congressional effort to stiffen the resolve of then-President Bill Clinton in responding to Russian support for Iran's nuclear ambitions.

The prohibition has never taken effect because of a previous agreement under which Russia agreed to provide 11 free Soyuz trips to the United States. The flight that took U.S. astronaut William S. McArthur Jr. to the space station early this month was the 11th.

Without a change in the Nonproliferation Act, U.S. astronauts would now have no way to reach the space station as long as the space shuttle remains grounded because of safety questions. A docked Soyuz serves as the station's emergency escape vehicle even when the shuttle is flying.

NASA Administrator Michael D. Griffin sent Congress a proposed amendment in July to effectively allow the United States to buy Russian space technology for as long as it is needed.

Lugar's bill would terminate purchases in 2012, while the bill passed by the House would terminate all purchases and contracts by Jan. 1, 2012, extend the underlying sanctions policy to include nuclear imports by Syria from governments as well as unspecified "entities," and strengthen the law to cover nuclear exports from Iran and Syria as well as imports by those countries.

Ground personnel help U.S. astronaut John Phillips after he returned from the space station and landed in Kazakhstan aboard a Russian spacecraft.