Jaime Lerner

Many cities end up putting off things because they want to understand everything. They don't understand that innovating is about starting. Taking care of a city is a process that you start, and then give the population space to respond.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.