...
- Rocket maximum revolution rate
- Rocket moment of inertia
Formulas in parens aren't finished.
Conservation of angular momentum gives that Irwr + Iwww = 0, which can be rearranged to say that (Iw / Ir = wr / ww), to find the rotational inertia the wheel should have, knowing the rocket's and wheel's maximum revolution rates, and the rocket's moment of inertia. However, the rocket's moment of inertia is relatively harder to measure, so the mass can be used to approximate.
...
- Underestimate of reaction wheel mass: The maximum revolution rate underestimates the angular momentum the wheel needs to remove from the rocket.
- Overestimate of reaction wheel mass: The mass ratio (intentionally) overestimates the necessary inertia ratio, as described.
- Underestimate of reaction wheel mass: The radii of the wheel and rocket are assumed to be equal; however, the wheel's radius is necessarily smaller.
...
- .