Sling effect
|
|
Sling effect is an effect of accelerating a body in space (as e.g. a space probe) through a gravitational interaction with another body in its vicinity (as e.g. a planet). It is called sling effect if the momentum and the kinetic energy of the body under consideration are increasing and dynamical friction if they are decreasing.
The effect is based on the fact that gravitational interactions between bodies in space during their passing by each other are the same as in elastic collisions (in which total kinetic energy of the colliding pair is conserved). It is possible to position the space probe behind the planet, while the probe is passing the planet, in such a way that gravitational interaction with the planet gives a kick to the probe at the expense of planet's momentum and kinetic energy, as if the probe collided elastically with the planet. This way the space probes can be accelerated to much greater velocities than could be reached through the application of any other known type of propulsion.