Princess Diana

You make your first album, you make some money, and you feel like you still have to show face, like 'I still go to the projects.' I'm like, why? Your job is to inspire people from your neighborhood to get out. You grew up there. What makes you think it's so cool?

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.