Gravity is the force needed to maintain the orbit of planets, asteroids and comets around a star and moons and artificial satellites around a planet. An artificial satellite is a man-made body ...

Ion thrusters are the most common primary engine powering satellites through orbital ... of ion thruster capable of achieving ...

The attractive force of gravity also keeps moons and artificial satellites in orbit around a planet. The Moon is a natural satellite. An artificial satellite is a man-made body placed in orbit ...