The Ulysses spacecraft, the first to reach the poles of the Sun, accomplished its task by playing planetary billiards.
Most spacecraft operate in the plane of the Earth's orbit.
Getting out of the plane of the Earth's orbit requires enormous energy, and Ulysses got its energy from a gravitational bounce at Jupiter. To enable Ulysses to reach the Sun's south pole, the NASA space shuttle launched the craft toward Jupiter in October of 1990. As Ulysses flew past Jupiter, the planet's gravity pulled it around and gave it an enormous push in the direction of the south pole of the Sun. Ulysses' journey from launch to the south pole took nearly four years. The spacecraft traveled almost five years and 1.86 billion miles from launch, over the Sun's south pole and on to the Sun's north pole.