MOSCOW  After months sealed in an isolation chamber, participants in a simulated mission to Mars emerged into a muggy Moscow afternoon on Tuesday, completing what international scientists hope is a small step toward a staffed mission to the red planet.

The six participants  four Russians, a German soldier and a French airline pilot  spent 105 days locked in a series of hermetically sealed tubes as part of the Mars-500 project at the Institute of Biomedical Problems here.

An actual staffed mission, if one occurs, could be decades off, but Russian scientists and officials said the Mars-500 project, which will culminate in a 520-day isolation experiment scheduled to start next year, was an indication of Russia’s revitalized role in space exploration after years of struggling to keep a foothold in orbit.

“At this time we are moving from the era of preserving Russia’s place in space to its advancement,” Vitaly A. Davydov, the deputy chief of the Russian Federal Space Agency, said at a news conference. “This is a promising project that will guarantee the orbital deployment of equipment that will fly to the moon and Mars.”