Page 60 - Intro to Space Sciences Spacecraft Applications

Orbital Principles

Figure 2-1 0. Satellite constellation. Multiple satellites can be placed into 47
mutually supporting orbits.

ORBIT ESTABLISHMENT AND ORBITAL MANEUVERS

This section is included to give an orbital mechanics view of orbit
establishment and orbital maneuvers. This topic is discussed again in
Chapter 3 which deals with the propulsion concepts needed to perform
these maneuvers.
Orbit Establishment

It was stated earlier that the total specific energy of an object in orbit
was constant and could be determined from equation 2-8, which is repeat-
ed here for convenience.

For spacecraft, this energy is usually established by having a launch
system carry the payload to a specific altitude r = & + h with a specific
velocity v before burning out. It must be remembered that the velocity is
a vector quantity having both magnitude and direction. If the launch vehi-
cle establishes a velocity magnitude and direction that corresponds exact-