The heads of five agencies building the International Space Station staged talks here Thursday on tackling a looming transport problem for the ISS and gave positive signals for extending the orbital outpost's life beyond 2015.
The ISS will need extra transport for crew and freight to substitute for the US space shuttle, scheduled to be retired in 2010 when the ISS is completed.
A US replacement for the shuttle, a rocket-and-capsule system called Aries-Orion, is due to be operational around 2015.
The head of the Russian Space Agency, Anatoly Perminov, told reporters that the United States and Russia will hold talks on beefing up flights by the Soviet-era workhorse, Soyuz, to ferry astronauts to and from the ISS between 2011 and 2014.
"By the end of this year or by the beginning of next year at the latest, the whole rationale for our cooperation will be laid out," Perminov told a press conference at European Space Agency (ESA) headquarters.
Possible shuttle substitutes for freight, mulled by the agency chiefs, are commercial operators as well as Japan's unmanned cargo ship, the H-II Transfer Vehicle (HTV), due to be launched for the first time next year by its H-2 rocket, the Russian supply vessel Progress, and ESA's own cargo ship, which docked automatically with the ISS in March.