NOORDWIJK, Netherlands —

Europe’s space-exploration program has given itself about five months to conclude agreements with NASA and Russia for a planned European-led Mars rover mission in 2013, and to secure nearly $500 million in new funding that the program will need from European Space Agency (ESA) governments, the program’s director said.

The program also is under a deadline to firm up a cooperative effort with Russia and Japan on a crew transportation vehicle for future exploration, an effort that has been slowed by disagreements on work share among Europe’s prime contractors.

Daniel Sacotte, ESA’s director of human spaceflight and exploration, said the cooperation accord the agency is trying to reach on its ExoMars mission would include NASA-furnished experiment hardware, Russian-supplied nuclear-powered heaters for the ESA rover and the launch of ExoMars aboard a Russian Proton rocket.

ESA would provide the remaining rover elements and a Mars orbiter to provide telecommunications relay both for ExoMars and future Russian or U.S. missions as part of an agreement with NASA to assure continuous communications services from Mars for the coming years. Both agencies plan several missions to Mars.

orbiter also could be used for Russia’s Phobos-Grunt sample-return mission to the Martian moon, Phobos, which would carry telecommunications gear provided by Europe.

In a June 28 briefing at ESA’sEstec technology center here, Sacotte said ExoMars, which was approved by ESA governments in December 2005, will need substantial new financing to provide the minimum level of scientific return demanded by ESA’sExoMars backers.

Instead of a launch of a bare bones science payload aboard a medium-lift Soyuz rocket, ExoMars now is being designed for launch aboard a heavy-lift vehicle – Europe’s Ariane 5 or Russia’s Proton – with triple the mass of scientific instruments, as measured in kilograms.

Instead of the 650 million euros ($876 million) approved by ESA governments in December 2005 for a 2011 Soyuz launch, ESA is preparing to ask its delegations to back a billion-euro mission to lift off in 2013 aboard a heavy-lift Ariane 5 or a Proton.

“We need a decision on this in November to get our teams working on this cooperative scenario,” Sacotte said. “It would solve several problems we have with ExoMars, notably the insufficient science payload in a Soyuz launch. If we reach an agreement with Russia on a Proton launch, it would save us an investment in making our launch site capable of handling nuclear payloads.”

ESA has long considered using Russian-provided nuclear heaters to keep the ExoMars rover’s instruments from freezing. Europe has not developed this radioisotope energy power source for space missions, and securing it from the United States would be difficult given U.S. technology-transfer restrictions, ESA officials said.

But integrating the Russian nuclear technology into an ExoMars rover launched by a European Ariane 5 rocket would require that new safety and security procedures be developed and qualified at Europe’s Guiana Space Center in French Guiana. Launching ExoMars aboard a Russian Proton vehicle would spare ESA that difficulty, he said.

Russia’s Roskosmos space agency, ESA and NASA are three of the 14 space agencies worldwide that are crafting a long-term space-exploration strategy whose core idea is to coordinate missions and thus save money.

This Global Exploration Strategy also includes future crew-transportation systems. With the United States disinclined to share work on its future Orion vehicle with non-U.S. partners, Europe and Japan have both turned to Russia for collaboration on a crew-carrying space vehicle.

said it took six months just to reach an agreement with European contractors – mainly Astrium Space Transportation and ThalesAlenia Space – on their respective roles in the work, and another few months for Roskosmos to determine that RSC Energia would be Russia’s lead contractor. ESA has about 18 million euros to spend.

The Japanese space agency, Jaxa, has said that it too would like to take part in a program that included European and Russian investment. Sacotte said Jaxa officials reiterated their position in meetings during the recent Paris air show.

problem now is that it needs to develop a concrete program with Russia and Japan in time to be able to ask for financing from ESA government ministers at a meeting scheduled for October or November 2008. The major proposals for this meeting likely need to be presented to ESA delegations by mid-2008.

“I would like to spend 18 months refining the vehicle and the roles of the various partners,” Sacotte said. “I don’t have 18 months. I have less than that. We’ll do what we can within these time constraints.”