Putting a Spacecraft into Orbit
You are in your rocket. Your potential energy U is set
by gravity; you can't change that.
You can change your kinetic energy K can be altered (by
firing rockets).
Changing K changes Etot.
So you change your orbit by firing your rockets.
|
Orbit
|
Velocity
|
Result
|
|
A
|
V=0
|
immediate crash
|
|
B,C
|
V << Vcirc
|
eventual crash
|
|
D
|
V < Vcirc
|
elliptical orbit (P=apogee)
|
|
E
|
V = Vcirc
|
circular orbit
|
|
F
|
Vcirc < V < Vesc
|
elliptical orbit (P=perigee)
|
|
G
|
V = Vesc
|
barely escapes (parabolic orbit)
|
|
H
|
V > Vesc
|
easily escapes (hyperbolic orbit)
|