A gravity assist or slingshot effect around a planet changes

Last updated: 6/21/2023

A gravity assist or slingshot effect around a planet changes a spacecraft s velocity relative to the Sun by entering and leaving the gravitational field of a planet To accelerate the spacecraft flies with the movement of tr planet taking a small amount of the planet s orbital energy to decelerate the spacecraft flies against the movement of the planet The sum of the kinetic energies of both bodies spacecraft and planet remains constant ju like an elastic collision but without physical contact This can be assumed to be like a tennis ball bouncing off a moving train Imagine throwing a ball at 30 Kmph toward a train approaching at 50 Kmph The engineer of the train sees the ball approaching at 80 Kmph and thes departing at 80 Kmph after the ball bouncing elastically off the front of the train Because of the train s motion however that departure is at 130 Kmph relative to the station This explanation might seem to violate the conservation of energy and momentum but the spacecraff s effects on the planet have not been considered The linear momentum gained by the spaceship is equal in magnitude to that lost by the planet though the planet s enormous mass compared to the spacecraft makes the resulting change in its speed negligibly small These effects on the planet are so slight because planets are so much more massive than spacecraft that they can be ignored in the calculation The main practical limit to the use of a gravity assist maneuver is that planets and other large masses are seldom in the night places to enable a voyage to a particular destination For example the Voyager missions which started in the late 1970s were made possible by the Grand Tour alignment of Jupiter Saturn Uranus and Neptune A similar alignment will not occur again until the middle of the 22nd century Diagram shows a simplified version of satellite approaching earth The velocity of satellite after it suffers slingshot effect from earth relative to earth is u and relative to sun is v Find the value of v u Satellite 10 000 km h Earth 100 000 kam h 1 Gere