Answer:
'The European spacecraft Rosetta was launched on March 2, 2004'. Rosetta is a European Space Agency-led robotic spacecraft launched to study the Comet 67P/Churyumov-Gerasimenko.
Article : Advances in Space Science
Next Question: When did NASA establish 'The Near-Earth Program Office'?
Previous Question: Which is 'The Second Largest Asteroid according to it's Diameter'?