28 April 2001 (Lunar Calendar 6 April 2001), the "Pioneer 10" signal back to the Earth lost connection with the Earth. 28 April 2001, the first human space probe "Pioneer 10" flew out of the solar system after eight months of loss of contact with the Earth, at 11 billion kilometers away from the space signal "Pioneer 10" to the Earth in March 1972, it was the first unharmed crossing the meteorite belt between Mars and Mercury, sending back the photos of Jupiter and Saturn; the first arrived at Jupiter; the first flew across the orbit of Pluto, leaving the solar system. The "Pioneer 10" probe in June 1986 flew out of the solar system, and retired on March 31, 1997, it is currently about 11 billion kilometers away from the Earth, it will continue to the direction of Jupiter, if it passes