NASA scientists found that the flight speed of spacecraft "Pioneer-10", "Pioneer-11", "Galileo", "Ulysses" decreases faster than it requires calculations in accordance with gravity laws. Rough explanations for this incomprehensible phenomenon appeared. In this connection, the question arose about the existence of an unknown force, about the attraction of an invisible object, about the violation of the laws of gravity, about the revision of the current notion of gravitational forces. Explanation of the possible cause of deceleration of spacecraft flights can be found in the work published earlier by us (Space Sci.&Technol., 1999, 5(2-3), 113), where it is shown that if we imagine the planets "kakby" by electrons, the Sun is a kind of oxygen nucleus, and Pluto is very close to it in terms of Neptune's satellite, Triton - like a nucleus of hydrogen, then the structure of the Solar system will be similar to the structure of water.