The unmanned European Space Agency spacecraft will enter orbit around the comet 67P/Churumov-Gerasimenko Wednesday morning starting at 4 a.m. ET. The ESA is streaming the event live.
The comet is currently between the orbits of Mars and Jupiter.
Recent photos from Rosetta show that the comet, which is roughly three kilometres by five kilometres in diameter, has an irregular duck-like shape and rotates about once every 12.4 hours.
The car-sized, three-tonne spacecraft will follow the comet toward the sun for the next few months, before deploying a lander to touch down on the comet's surface in November.
Rosetta blasted off from Earth on March 2, 2004. Since then, it has travelled more than six billion kilometres, passing Earth three times and Mars once in order to get boosts from their gravity.
The mission will have an estimated cost of 1.3 billion euros ($1.9 billion).