Space Propulsion - IAP/TU Wien
Space Propulsion - IAP/TU Wien
Space Propulsion - IAP/TU Wien
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1 – axis maneuvre, cont‘d<br />
<strong>Space</strong> <strong>Propulsion</strong><br />
total angle of rotation is<br />
rotation during coasting is<br />
Θ m<br />
= Θ (accelerating) + Θ (coasting) + Θ (braking)<br />
Θ = ωtc<br />
the coasting rotation angle is<br />
Θ =<br />
nFL<br />
t<br />
I<br />
v<br />
b<br />
t<br />
c<br />
ω =<br />
nFL<br />
I<br />
v<br />
t<br />
b<br />
total rotation during acceleration, coasting and braking is<br />
Θ<br />
m<br />
⎛ nFL<br />
= 2<br />
⎜ t<br />
⎝ 2I<br />
v<br />
2<br />
b<br />
⎞ nFL<br />
⎟ + t<br />
⎠ I<br />
v<br />
b<br />
t<br />
c<br />
=<br />
nFL<br />
I<br />
v<br />
2<br />
( 2t<br />
+ t t )<br />
b<br />
b<br />
c<br />
Θ =<br />
nFLt<br />
2I<br />
v<br />
2<br />
b<br />
maneuver time is<br />
t m = t C + 2t b<br />
accel.<br />
minimum rotation time is a fully powered<br />
maneuver with zero coast time<br />
t<br />
min<br />
= 2t<br />
b<br />
=<br />
2. Θ<br />
m<br />
I<br />
nFL<br />
v<br />
thrust level required for each thruster<br />
at given minimum rotation time<br />
F<br />
Θ m v<br />
2<br />
min<br />
I<br />
= 2<br />
nLt<br />
propellant required for a one-axis<br />
maneuver is twice the single burn consumption<br />
m<br />
p<br />
nFt<br />
b<br />
= 2 =<br />
I<br />
sp<br />
nFt<br />
I<br />
sp<br />
min<br />
nFt<br />
b<br />
m<br />
p<br />
= =<br />
I<br />
sp<br />
H<br />
LI<br />
sp