Galileo has captured breathtaking images of Jupiter and its moons since 1995, but it is now scheduled to break apart as it enters Jupiter's atmosphere.
"Galileo mission draws to a close on 21 September with a plunge into Jupiter's atmosphere," the National Aeronautics and Space Administration said in a statement.
The administration added the collision course was a necessary measure to eliminate any possibility of the spacecraft crashing into the moon of Europa, which is likely to have a subsurface ocean.
Technicians expect Galileo - named after 17th Century Italian astronomer Galileo Galilei who discovered Jupiter's four key moons - to beam back a few hours of final scientific readings before it disintegrates.
The NASA statement explained that it is necessary to ditch the spacecraft, which was launched by the space shuttle Atlantis in 1989, because the craft is almost out of fuel.
"Without propellant, the spacecraft would not be able to point its antenna toward Earth or adjust its flight path, so controlling the spacecraft would no longer be possible," NASA said.
Galileo found evidence of subsurface salt water on Jupiter's moons Europa, Ganymede and Callisto, as well as detecting high levels of volcanic activity on Io.