Final answer:
The statement is false; Kepler's laws of planetary motion do not require a planet-satellite system to be completely isolated from other massive objects, as these laws are an idealization and still hold well within our solar system despite other gravitational influences.
Step-by-step explanation:
The statement True or False: A planet-satellite system must be isolated from other massive objects to follow Kepler's laws of planetary motion is false. Kepler's laws of planetary motion can be applied to systems where a planet and its satellite(s) are gravitationally bound primarily to each other, and this assumption greatly simplifies the mathematics of their motion. However, Kepler's laws are an idealization and do not require complete isolation from other massive objects. In real-world scenarios, other celestial bodies such as stars, planets, and moons exert additional gravitational influences, which may lead to perturbations in the orbits predicted by Kepler's laws.
Nevertheless, in many cases, particularly within our solar system, the primary gravitational interaction between a planet and its satellite is sufficient to make Kepler's laws a very good approximation of their orbits.