According to Wikipedia: > New Horizons has been called "the fastest spacecraft ever launched" because it left Earth at 16.26 kilometers per second [...] Howeve

According to Wikipedia: > New Horizons has been called "the fastest spacecraft ever launched" because it left Earth at 16.26 kilometers per second [...] However, it is not the fastest spacecraft to leave the Solar System. As of January 2018, this record is held by Voyager 1, traveling at 16.985 km/s relative to the Sun. Voyager 1 attained greater hyperbolic excess velocity than New Horizons due to gravity assists by Jupiter and Saturn. When New Horizons reaches the distance of 100 AU, it will be travelling at about 13 km/s, around 4 km/s slower than Voyager 1 at that distance.