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Space Propulsion - IAP/TU Wien

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

Spiraling up<br />

time required to spiral up from r 0 to r<br />

assumption: T = const.<br />

•<br />

m = T / I dm/dt = const. •<br />

( )<br />

sp<br />

m = m0 − m t − t 0<br />

ΔV<br />

=<br />

t<br />

∫<br />

t0<br />

T<br />

m<br />

dt =<br />

T<br />

m<br />

0<br />

t<br />

∫<br />

t0<br />

m<br />

1−<br />

m<br />

dt<br />

•<br />

( t − t0<br />

)<br />

0<br />

⎡<br />

T<br />

⎢<br />

m<br />

= − ln 1−<br />

•<br />

m<br />

⎢ m0<br />

⎣<br />

⎤<br />

•<br />

( t − t0<br />

)<br />

⎥ ⎥ ⎦<br />

Δ V<br />

=<br />

μ −<br />

r<br />

0<br />

μ =<br />

r<br />

μ ⎛<br />

⎜1<br />

−<br />

r<br />

0 ⎝<br />

r<br />

0<br />

r<br />

⎞<br />

⎟<br />

⎠<br />

τ =<br />

t<br />

− t<br />

0<br />

=<br />

m<br />

•<br />

⎤⎫<br />

μ ⎞<br />

⎟<br />

m<br />

⎥⎪<br />

⎠ ⎦⎪<br />

⎭<br />

0<br />

sp<br />

1 exp<br />

m<br />

• ⎨ − −<br />

⎬ =<br />

0<br />

−<br />

⎢ ⎜<br />

−<br />

r0<br />

r ⎟ T ⎥ T<br />

m<br />

⎧<br />

⎪<br />

⎪<br />

⎩<br />

⎡<br />

⎢<br />

⎣<br />

⎛<br />

⎜<br />

⎝<br />

μ<br />

I<br />

−( vc,0<br />

−vc,1<br />

)/<br />

Isp<br />

[ 1 e ]

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