06.2a - Orbital Mechanics

Escape speed (v_esc) the speed an object needs to have at the surface of a planet in order to have enough kinetic energy to escape the planet’s gravitational pull. For an object at orbital radius r (m) about a planet of mass M (kg), the escape speed in m s–1 is given by vesc=2GMr, where G is the universal gravitational constant.

Orbital speed (v_orbit) the linear orbital speed of a satellite about a planet. At an orbital radius r (m) above a planet of mass M (kg), v_orbit (m s–1) is given by vorbit=GMr, where G is the universal gravitational constant.