It’s one of the fastest spacecraft ever launched. New Horizons entered directly into an Earth and Sun escape trajectory after launching on 19 January 2006 at a velocity of 58,536 km/h (36,373 mph), making it the fastest spacecraft to ever leave Earth orbit at the time, 100 times faster than a jetliner.
It’s now the closest manmade object to Pluto (and it’s getting closer). Until 2 December 2011 the Voyager 1 spacecraft held the “record” for the closest approach to Pluto, a mammoth 10.58 times further than the Earth-Sun distance. New Horizons is well within this record.
Its journey is almost equal to 32 trips between the Earth and the Sun. On 14 July 2015 – around 3,460 days after launching and having travelled 4.76 billion kilometres (2.96 billion miles) – New Horizons will become the first probe ever to fly past Pluto. It will observe the once ninth planet of the Solar System for several weeks.
It could hit a hidden Plutonian moon. Five moons are known to currently be in orbit around Pluto, but three of these were discovered in just the last couple of years. Pluto may have more moons, or other objects like asteroids, that could pose a threat to New Horizons as it approaches.
Its mission will continue beyond Pluto. New Horizons will use Pluto’s gravity to give it an additional speed boost to help it make its way into the outer Solar System. Here it will observe Kuiper Belt Objects until 2020 before the mission officially ends in 2026.