17.01.2014 Views

Space Propulsion - IAP/TU Wien

Space Propulsion - IAP/TU Wien

Space Propulsion - IAP/TU Wien

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

<strong>Space</strong> <strong>Propulsion</strong><br />

Kinetics for rotational motion of S/C<br />

Linear analogon<br />

torque, produced by n thrusters, mounted at torque arm L,<br />

firing with equal thrust F<br />

T = nFL<br />

F<br />

during the burn, the angular acceleration of the spacecraft is<br />

α =<br />

nFL<br />

I v<br />

a =<br />

F<br />

m<br />

at shut down, the vehicle will have turned by 2<br />

nFLtb<br />

2<br />

at shutdown, the spacecraft is left rotating at angular velocity<br />

Θ =<br />

ω =<br />

2I<br />

v<br />

v<br />

nFL<br />

I<br />

t<br />

b<br />

a<br />

s =<br />

2 t<br />

v = a.<br />

t<br />

angular momentum produced by a single firing is p =<br />

H = Tt b<br />

∫ Fdt<br />

propellant consumed during the burn is<br />

nFt<br />

b<br />

m<br />

p<br />

= =<br />

I<br />

sp<br />

H<br />

LI<br />

sp<br />

•<br />

= F m<br />

I sp<br />

/

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!