The director of Roscosmos, the Russian space agency, said Tuesday that cosmonauts in the next few years would begin flying to the International Space Station aboard NASA shuttles, and U.S. astronauts would fly aboard Russian Soyuz spacecraft.

Anatoli Perminov told the Itar-Tass news agency that he had discussed the issue last week in Washington with NASA administrator Michael Griffin, and they agreed they were concerned about lack of continuity and exchanges of experience in missions to the station by the two nations.

Perminov also said he had proposed lengthening individual missions aboard the orbiting facility to one year from the current six months, but he could not obtain NASA's approval.

He confirmed what had been announced at a briefing March 2 - that the crew size on the ISS would be increased to six astronauts by 2009, and said the increase would create room for Canadian, European and Japanese crew members to begin their own science missions aboard the station.

The proposed ISS crew configuration matches what was originally planned, but in the wake of the shuttle Columbia disaster on Feb. 1, 2003, the station partners agreed to pare crew size temporarily to two.

At the March 2 briefing, attended by all five heads of the station partner agencies - Canada, Japan and the European Space Agency, as well as Roscosmos and NASA - Griffin said the shuttles would make 16 more flights to the station, until 2010 when the fleet would be retired.

Perminov said the shuttle schedule also would include two back-up flights if necessary.

Copyright 2006 by Space Daily, Distributed United Press International