The key to earning the three star rating is to time the meteor rotations and taking a really great laser shot. First launch your bird with the angle and path shown in the picture.
Power Activation Point
Activate your lasers when all the pigs line up on the right side, your laser need to kill the right two pigs along with the green armor pig.
First Shot Result
After your lasers kill the pigs, the meteors fall from the sky and kill the rest. The three star mastery rating is then yours.