What if Larry Page decides he wants the future is to colonize the moon. Then, he decides to invests all or a large portions of Google's money in colonizing the moon. Will anyone stop him? Would this count as a startup again?
One of our biggest problems re space exploration and colonizing other planets is that our energy and propulsion systems suck for the task. Imho, materials science, nanotech, and further drilling down into sub-atomic mechanics is where we're more likely to make breakthroughs in things like energy generation, storage, and efficient propulsion.