Chapter 6: Maneuvering in Space Understanding Space Sellers

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Chapter 6 Maneuvering in SpaceUnderstanding
Space (Sellers)
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Supplemental References
1. Liftoff to Space Exploration
http//liftoff.msfc.nasa.gov/toc.asp?sOrbital20M
echanics 2. Thomson, William T., Introduction
to Space Dynamics, John Wiley and Sons,
Inc., 1961 3. NSSDC Image Catalog Mission Index
http//nssdc.gsfc.nasa.gov/imgcat/mission_index
.html
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Parking and Other Orbits(Apollo 8)
(NASA GSFC)
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Section 6.1 Hohmann Transfers
Start with
Need specific mechanical

energy and alternate form
For tangential burn
(NASA)
To solve for ?Vs, need energy in each orbit
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Hohmann Transfers
(NASA)
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Hohmann Transfers
(NASA)
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Section 6.2 Plane Changes
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Simple Plane Changes
Assume spacecraft in orbit with inclination, i
28.5, and want to change to i 0 Change
orbits orientation, not its size Velocity
vectors magnitude stays the same, but its
direction changes
Vinitial
?
?
?Vsimple
28.5
?
Vfinal
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Combined Plane Changes
Vinitial
?Vcombined
?Vsimple
?
Use law of cosines
Vfinal
?Vincrease
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Section 6.3 Rendezvous (Using Hohmann Transfer)
Rint
?V
Rtarget
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Rendezvous
Coplanar rendezvous
?final
Rint
?V
?lead
Rtarget
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Co-orbital Rendezvous
?initial
Phasing Orbit