Space exploration on 16 June 1963. China first launched a person into space 42 years after the launch of "Vostok 1", on 15 October 2003, with the flight of Yang Liwei aboard the "Shenzhou 5" (Divine Vessel 5) spacecraft. The first artificial object to reach another celestial body was Luna 2 in 1959. The first automatic landing on another celestial body was performed by Luna 9 in 1966. Luna 10 became the first artificial satellite of the Moon. The first crewed landing on another celestial body was performed by Apollo 11 on 20 July 1969. The first successful interplanetary flyby was the
Celestial navigation celestial body's GP and the observer's position. After some computations, referred to as sight reduction, this measurement is used to plot a line of position (LOP) on a navigational chart or plotting work sheet, the observer's position being somewhere on that line. (The LOP is actually a short segment of a very large circle on Earth that surrounds the GP of the observed celestial body. An observer located anywhere on the circumference of this circle on Earth, measuring the angle of the same celestial body above the horizon at that instant of time, would observe that body to be at