Scientists have been baffled by a mysterious phenomenon that has prevented the craft from moving further into outer space.
Described as a force that defies all laws of nature, they have said gravity laws may eventually need to be changed.
Defying all previously-known theories about the universe, the strange force that gently pushes spacecraft away from outer space was discovered last year when the spacecraft Pioneer 10 was stopped in its path by the unknown phenomenon.
Researchers for NASA have said the force could be a totally new phenomenon that does not fall under familiar titles such as gravity or electromagnetic power.
A tangible scientific explanation has not been put forward for the fact that the Pioneer 10 left the solar system to start its voyage in a space where there is no solar radiation or planets to attract it toward their orbits.
Pioneer 10, which travels more than one million kilometers per day, started slowing down in an area where it is not supposed to meet any obstacles.
Pioneer 10 is the first spacecraft to have taken close photos of Jupiter, which it passed in 1973.
In 1978, it traveled towards Pluto and reached it in 1983.
It then left for a region called the Asteroid Belt, which is occupied by several irregular-shaped minor planets.
The spacecraft, which is currently 11 billion kilometers away from earth, now only travels at 25 centimetres every day, going backwards.