E uropean Space Agency (ESA) governments agreed June 22 to participate in a two-year program with Russia, and probably Japan as well, to explore crew-transport vehicle designs for missions to the international space station, the Moon and elsewhere.

The Russian-proposed program, formerly called Clipper, has evolved into a more modest effort to start with an evolved and enlarged Soyuz capsule as a design focus. Only later would the program, now called Advanced Crew Transportation System (ACTS), move to a possibly winged spacecraft along the lines of what the Russians have proposed for Clipper.

Daniel Sacotte, ESA director of human spaceflight, microgravity and exploration, said in a June 22 interview that ESA governments led by France and Germany had agreed to invest around 15 million euros ($19 million) on a two-year, collaborative effort with Russia to settle outstanding ACTS issues.

These issues include a division of labor between the Russian and European companies on development of the major ACTS systems — docking, leading-edge materials, avionics and other technologies. ESA has insisted that it be given development authority over a mission-critical system and not be limited to a subcontractor’s role. Sacotte said the Japanese space agency, JAXA, has indicated that, if Europe joins Russia in the program, Japan will do likewise.

By 2008, Sacotte said, the partners should be in a position to determine whether a full-scale development effort is warranted.

More immediately, Sacotte said, the Russian space agency, Roskosmos, this summer will select a Russian prime contractor for the ACTS studies. Europe then will assemble a consortium of its own to work with the Russian company.

ESA’s principal member states, including France, Germany, Italy and Belgium, have all indicated that they want to participate in the development of a manned vehicle that would be capable of performing a range of missions in the post-shuttle era. The U.S. space shuttle is scheduled to be retired in 2010.

European government officials have said they will not embark on a solo development effort. They have approached NASA about joining the U.S. Crew Exploration Vehicle program but have been rebuffed by the current U.S. government policy of making the vehicle off limits to non-U.S. participants.

Russia has taken the opposite approach, and has solicited ESA involvement in designing a vehicle that would carry six astronauts and be capable of rendezvous and docking in orbit, and ultimately of carrying out manned lunar missions and perhaps Mars exploration as well.

Roskosmos had asked ESA last December, during a meeting of ESA government ministers, to take part in Clipper development. ESA governments declined to commit themselves then, saying Clipper’s design and mission goals were ill-defined. They said they would review the program in June.

Russia’s Soyuz rocket is being modified for launch from Europe’s equatorial Guiana Space Center in French Guiana, with a first launch scheduled for late 2008. That vehicle is designed to carry only satellites, not astronauts. But Russian and European officials say an ACTS agreement would include both the French Guiana site and Russia’s Baikonur Cosmodrome in Kazakhstan as launch bases for future manned ACTS missions.

Sergio Vetrella, president of the Italian Space Agency, said June 21 that Italy likely will be contributing to the two-year study effort at ESA in the hope that, by 2008, ACTS’ mission and design are more clearly designed.

Sigmar Wittig, executive chairman of the German aerospace center, DLR, said June 21 that Germany also would take part in the two-year ESA-led work, but that ACTS and Clipper are not ready to go beyond the study phase.

“I start with data points,” Wittig said. “One data point is the shuttle’s announced retirement in 2010. Another is the need for a six-passenger vehicle to serve the space station. A third is Russia’s plans to upgrade or replace the current Soyuz capsule. These are starting points. Obviously more are needed.”

Sacotte said the two-year study would include negotiations with Russia on how to treat technology transfer between Europe and Russia. He said discussions so far with Roskosmos have led him to believe that these concerns will not be major obstacles.

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