No problem... it turns out we reverse engineered a primitive FTL drive from the debris at Area 51, so we stick it onto a Space Shuttle, but it also turns out to be the only thing powerful enough to blow up the star, so it has to be detonated, sacrificing the ship.

However,the explosion also creates a wormhole that Bruce Willis bounces back into after blowing the star up, which lets him land safely back on Earth in a cool pose like Iron Man at the end.