text: The orbital speed of a body , generally a planet , a natural satellite , an artificial satellite , or a multiple star , is the speed at which it orbits around the barycenter of a system , usually around a more massive body .
simplified: The orbital speed of a body , usually a planet , a natural satellite , an artificial satellite , or a multiple star , is the speed at which it orbits around the barycenter of a system , usually around a more massive body .