[cordite]

How big and how fast must a flywheel be to perturb Earth's rotation, in a similar method of https://en.wikipedia.org/wiki/Control_moment_gyroscope

[ricardobeat]

The rotational energy of the planet is absolutely massive. I don't remember the numbers but you'd need millions of atomic bombs fired at once just to make a dent - and it would still not affect the orbit of this now radioactive fireball at all.