AstroGrav Help / Sample Simulations / Space Missions

Space Missions

The following simulations are examples of space missions in which "gravity assists" were used to reach the mission target.

New Horizons shows the path followed by the New Horizons spacecraft.
Pioneer shows the paths followed by the Pioneer 10 and Pioneer 11 spacecraft.
STEREO shows the paths followed by the STEREO-A and STEREO-B spacecraft.
Ulysses shows the path followed by the Ulysses spacecraft.
Voyager shows the paths followed by the Voyager 1 and Voyager 2 spacecraft.

During a gravity assist, a spacecraft passes very close to a planet (or other massive body) and is accelerated towards its target by the planet's gravity. In some missions, more than one gravity assist is used to reach the target. The exact position and velocity at which a spacecraft emerges from a gravity assist is very sensitive to the position and velocity at which it enters the gravity assist, and so minor 'course correction manoeuvres' are used to keep it on an accurate course. AstroGrav cannot easily simulate course correction manoeuvres, and so multiple gravity assists (such as Voyager 2) are not particularly well simulated.

The starting date for each simulation has been chosen to best illustrate the gravity assist(s), and where possible, more than one spacecraft has been included in a single simulation.