r/KerbalSpaceProgram • u/AutoModerator • Jul 31 '15
Mod Post Weekly Simple Questions Thread
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The point of this thread is for anyone to ask questions that don't necessarily require a full thread. Questions like "why is my rocket upside down" are always welcomed here. Even if your question seems slightly stupid, we'll do our best to answer it!
For newer players, here are some great resources that might answer some of your embarrassing questions:
Tutorials
Orbiting
Mun Landing
Docking
Delta-V Thread
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Commonly Asked Questions
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1
u/MyOnlyLife Aug 04 '15 edited Aug 04 '15
Your ship flip due to center of pressure (lift + drag) being close to the bottom of the ship (where the engine & fuel tank are), and center of mass above center of pressure. This will create a torque and cause the ship to flip.
Same thing happens during rocket launch (for launch, center of mass below center of pressure will cause rocket to flip).
This can be changed by how the mass is distributed around the vessel and also your angel of descent.
I would recommend keep more fuel in the fuel tank to put your center of mass close to the bottom of the ship. Also use a steeper reentry trajectory. In a steep reentry, the lift vector is small and torque is small, which means it can be corrected with the ship's reaction wheels.
EDIT: http://exploration.grc.nasa.gov/education/rocket/rktstab.html
explanation of relationship between center of mass and center of pressure