Quoting from the article "Newton's theory of gravitation, while incomplete over vast distances and enormous speeds, is perfectly suitable for the Solar System.

Quoting from the article "Newton's theory of gravitation, while incomplete over vast distances and enormous speeds, is perfectly suitable for the Solar System. Halley's Comet appears punctually as Newton's theory of gravitation and laws of motion predict. All of rocketry is based on Newton, and Voyager II reached Uranus within a second of the predicted time. None of these things were outlawed by relativity." We need relativity to correct the atomic clocks on GPS satellites so as to maintain positional accuracy to a few feet, but getting the satellites up there needed only Newtonian mechanics.