- published: 12 Jun 2015
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New Horizons is a NASA robotic spacecraft mission currently en route to the dwarf planet Pluto. It is expected to be the first spacecraft to flyby and study Pluto and its moons, Charon, Nix, Hydra and S/2011 P 1, with an estimated arrival date at the Pluto-Charon system of July 14, 2015. NASA may then also attempt flybys of one or more other Kuiper belt objects, if a suitable target can be located.[citation needed]
New Horizons was launched on January 19, 2006, directly into an Earth-and-solar-escape trajectory with an Earth-relative velocity of about 16.26 km/s (58,536 km/h; 36,373 mph) after its last engine was shut down. Thus, the spacecraft left Earth at the greatest-ever launch speed for a man-made object. It flew by the orbit of Mars on April 7, 2006, the orbit of Jupiter on February 28, 2007, the orbit of Saturn on June 8, 2008; and the orbit of Uranus on March 18, 2011. Since February 2012, its distance to Pluto is less than 10 AU (more than 20 AU from Earth).
As of February 12, 2012[update], the spacecraft was traveling at 15.41 km/s, or about 3.249 AU per year, at a distance of 21.99 astronomical units (3.290×109 km) from the Sun and 22.97 astronomical units (3.436×109 km) from Earth, just beyond the orbit of Uranus. The spacecraft was at a declination of −21.44 degrees, and a right ascension of 18.483 hours at that time. At that distance, light takes about 3.03 hours to reach the spacecraft from Earth, meaning that a round trip time for a radio signal was about 6.06 hours.