PRAGUE, Czech Republic — The European Space Agency (ESA) will be seeking the approval of is member states late this year to extend its participation in the international space station to 2020, a decision that will bind participating nations to preset budget contributions, ESA officials said Sept. 27.

ESA officials hope to use their member governments’ approval of a five-year extension to win endorsement for development of a reusable version of Europe’s Automated Transfer Vehicle, an unmanned freighter that delivers supplies to the station and reboosts the station’s orbit before being filled with garbage and burned up on a controlled re-entry into the Earth’s atmosphere.

If the station’s service life is extended to 2020, the agency has a greater incentive to replace the Automated Transfer Vehicle with an Advanced Re-entry Vehicle (ARV) that would return cargo to Earth.

ESA’s space station director, Simonetta di Pippo, said none of the agency’s delegations has voiced opposition to the five-year extension and that she is confident it will be approved. If that is the case, she said, the agency will propose to its governments to spend some 150 million euros ($200 million) on preparations for an ARV. Full development, which would cost considerably more, would then be proposed to ESA government ministers scheduled to meet sometime in 2012.

Speaking to reporters here during the 61st International Astronautical Congress, di Pippo said a decision to develop ARV would be accompanied by the cancellation of the sixth and seventh Automated Transfer Vehicle. Money saved on building these vessels would offset some of the ARV development costs. A full ARV program approval in 2012 would permit the agency to begin flying the vehicle perhaps around 2017.

ESA has agreed to repay NASA, the space station’s general contractor, in services rather than cash in return for NASA’s provision of the station’s operating expenses, which among other things permits ESA’s Columbus habitable module to function. Automated Transfer Vehicle cargo-delivery and station-reboost flights are part of that payment. ARV would take over that role.

ESA Director-General Jean-Jacques Dordain said here Sept. 27 that while he is confident that the five-year extension has the approval of all European nations participating in the station, he does not want a general agreement without specific guarantees on which nation will pay how much of the associated costs.

For now, Germany, France and Italy pay the dominant share of ESA’s space station expenses. These nations presumably will be asked to continue financing the project through 2020.

“There is no objection to extending the station’s operations to 2020,” Dordain said. “What still needs to be decided is the cost, and the scale of contributions. I don’t want an approval now without deciding this aspect as well. I hate decisions that are ‘subject to availability of funds.’ What we need to agree to now is the distribution of costs. That is the difficult part.”

Peter B. de Selding was the Paris bureau chief for SpaceNews.