Difference between sub-orbital and orbital spaceflights: Difference between revisions

Revision as of 16:59, 26 August 2005

Revision as of 04:01, 18 November 2005

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==Angular velocity==

An orbital spaceflight is achieved when the spacecraft travels around the Earth in space at sufficient lateral velocity (or equivalently, enough [[angular velocity]]) forto "miss" the Earth, even though [[centrifugal forcegravity]] tois cancelstill outeffecting theit, pulland of"free-fall" Earth'sforever. [[gravity]]. Lateral velocity is the speed of something around an object and it is this which is the critical factor. Although the angular velocity required is a function of the height of the orbit, orbital spaceflight is possible at any altitude beyond the edge of space.

A body which does not have sufficient angular velocity cannot orbit the Earth. The actual speed of a sub-orbital spacecraft could exceed that of an orbital one and the height that a sub-orbital spacecraft attains may even exceed that of an orbital one, but the critical difference between the two - the achieving of an orbit - depends crucially on the angular velocity. Travelling straight up will never result in an orbit, doing so faster than [[escape velocity]] will have the obvious effect and orbit is still not attained.