New Horizons is the fifth most distant spacecraft from Earth.
Pioneer 10, which was launched in 1972 and was the first probe to pass through the asteroid belt and to fly by Jupiter, reached 50 AU on Sept. 22, 1990. Today, it is approximately 129 AU from Earth.
Its sister ship, Pioneer 11, reached 50 AU a year later in 1991. It was launched in 1973 and in addition to flying by Jupiter, was the first to make direct observations of Saturn. It is now about 105 AU from Earth.