Rosetta is the first spacecraft ever to tailgate a comet – in a decade-long mission that scientists hope will unlock the secrets of the solar system.
Launched by the European Space Agency (ESA) in 2004, Rosetta finally caught up with its quarry, the comet named "67P/Churyumov-Gerasimenko", rendezvousing with it on Aug 6. It will now accompany the hunk of ice and rock on its trip around the sun and land a probe on it in November this year in an unprecedented manoeuvre.
Because it's never been done before, ESA scientists are on a tight schedule to learn as much as they can about the comet using data from Rosetta to safely land the spacecraft’s probe, called Philae, on it. “We know what the comet’s shape is. But we haven’t really measured its gravity, we don’t know yet where the centre of mass is,” Rosetta flight director Andrea Accomazzo said, ahead of the rendezvous.