Operation Hard Rock will assault the Earth's surface with rocks, with a goal of maximum destruction and minimum loss of life. The first target is North American Directorate.
To ensure a minimum loss of life, they send warnings to Earth for three days straight.
Okay, we know what you're thinking, why don't the Federated Nations just bomb them with ships? Well, Mannie explains that ships are expensive and sending them up to the Moon adds to the cost. Also, you remember what happened to the last ship, right?
On the day of the bombing, Mannie leaves Mike alone so the calculations can go smoothly, and goes out with some binoculars to watch the moon rocks hit.