A mission that will scour space for Earth-like planets is scheduled for launch on Wednesday.
Corot will be the first spacecraft capable of detecting planets outside of the Solar System that are just a few times larger than the Earth.
The French-led multinational mission will also help uncover the secrets of stellar interiors.
Corot will be launched at 1443 GMT from the Baikonur Cosmodrome in Kazakhstan on the Soyuz-2-1b vehicle.
We've been waiting 25 years to get such a mission into space Professor Ian Roxburgh It will be taken into a polar orbit 827km (514 miles) above the Earth where it will survey star fields for approximately 2.5 years.
The mission is led by the French space agency, Cnes, which is working with six international partners: European Space Agency (Esa), Austria, Spain, Germany, Belgium and Brazil.
"We've been waiting 25 years to get such a mission into space," said Ian Roxburgh, professor of astronomy at Queen Mary, University of London, UK, and the Esa member of the Corot scientific committee.
"It will be the first space mission that will be searching for planets around other stars that are of a similar nature to Earth.
"We should be able to detect them down to about twice the size of Earth."
He added: "We will also be monitoring a substantial number of stars to find out what they are like inside and to see how they evolve over time."
1. 4CCD camera and electronics: captures tiny variations in a star's brightness 2. Baffle: shields telescope lens from light pollution3. Telescope: views the star fields4. Proteus platform: contains communication equipment, temperature controls and direction controls5. Solar panel: the Sun's radiation is a source of power for the satellite