ASTR 101 Lecture Notes - Lecture 13: Beach Ball, Toy Model, Weightlessness
6 Sep 2016
School
Course
Professor
Document Summary
Definition: objects moving only under the influence of gravity (no rockets firing, no air resistance, etc. ) are said to be moving ballistically. (newton"s imagined cannonball was such an object) To create this motion: launch something fast, then shut off the motors or driving force and let is coast thereafter. In the cold war, fear of intercontinental ballistic missiles. Fear was that these could be launched with the engines shutting off right away, after which nuclear weapons would coast ballistically over the oceans and land on their targets with no way of diverting them. Use knowledge to allow the design and launching into orbit of artificial satellites. Tens of thousands of them orbiting the earth, including telecommunication satellites, spy satellites, weather satellites, those that monitor resources, and astronomical satellites (hubble) Takes a lot of energy to launch a satellite into every high orbit, but some are at modest altitudes.
