The NASA Juno spacecraft is headed for Jupiter. Launched August 2011, it is scheduled to arrive July 4, 2016. On October 9, 2013, Juno coasted by the Earth and used gravity assist to speed it up and redirect it slightly so it will coast the rest of the way toward Jupiter. It received a boost in speed of more than 8,800 mi/hr (about 7.3 km/s). It is currently right on course. You can read about that flyby in this news release from the mission website.