PARIS — A European science panel has selected a dark-energy probe, a joint solar science mission with NASA and a space telescope designed to look for Earth-like planets around stars as the three finalists for Europe’s next space-science competition, according to European officials familiar with the selection.

The outgoing president of the panel, called the Space Science Advisory Committee (SSAC), confirmed the choices in a Jan. 19 interview and said a fourth mission proposal — a less-expensive collaboration with Japan on an infrared space telescope — also has been endorsed. But this mission, called the Space Infrared Telescope for Cosmology and Astrophysics (SPICA), will have to secure financing from outside the budget allocated to the current round of science-mission selections, he said.

TilmanSpohn, director of the Institute of Planetary Research in Berlin, which is part of the German Aerospace Center, DLR, said the SSAC eliminated from the competition two missions that were deemed too expensive to fit into the budget guidelines set by the 18-nation European Space Agency (ESA).

The Marco Polo asteroid sample-return mission and the seven-satellite Cross-Scale proposal to study the Earth’s plasma layer both were viewed as “superb from a science standpoint,” but beyond Europe’s current budget.

“They were both eliminated because they were solidly above the budget ceiling and there was no way to develop the missions within the budget guidelines without compromising the science,” Spohn said.

The SSAC’s selection, made during a Jan. 15 meeting, will be forwarded to Europe’s Science Program Committee for a final ruling expected Feb. 18. While this committee is free to discard the SSAC proposals, it usually accepts the lower body’s recommendations.

The three selected candidates are all either near or above the budget ceiling of 475 million euros ($683 million) that ESA had set for its next series of so-called M-Class missions to be pursued under the agency’s multiyear Cosmic Vision science program.

Euclid, envisioned as a satellite to map dark energy, is estimated to cost 500 million euros. Several European science managers had questioned whether Euclid’s complexity would inevitably push costs much higher.

Spohn said several SSAC members raised this during the debate on mission selection. “There was some questioning of the cost estimate for Euclid, but at some point you have to decide: Either you don’t believe the estimates that [ESA science program managers] produced, or you assume their estimates are credible. Euclid was the one mission where costs were debated, but the consensus was to use the cost estimates presented to us.”

The Solar Orbiter mission, to be developed in collaboration with NASA, is estimated to cost ESA some 490 million euros.

Plato, which will look for Earth-like planets around nearby stars, has been estimated to cost 460 million euros.

For all these missions, the cost estimates are only for elements that ESA will finance. The agency typically leaves science instrument development to its member nations’ national laboratories, which have their own budgets.

Once approved by the Science Program Committee, the selected missions will be pursued through separate Phase-A design contracts. In late 2011, full development will begin, with a final review in mid-2012 scheduled to verify that the mission costs have not risen prohibitively by then.

The missions that survive this process are scheduled for launch in 2017-2018.

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