How much did it cost?
The overall budget of the mission, is approximately 1.3 billion of current euros, for which nearly 20 % was provided by France.
What did France do? What did CNES do?
Through the national contribution to the budget of the European Space Agency, French industry took part in the realization of the Rosetta orbiter (EADS Astrium, Thomson tubes...) and of the launcher (Arianespace, EADS Launcher, SNECMA...).
Moreover, CNRS and CNES cooperated to provide instruments of the scientific payload.
Lastly, with 9 other partners, CNES designed, developed and tested the Philae Lander whose science scheduling and monitoring are performed from the Toulouse space center.