How do we get there? How do we get there without using the earth as our fuel?
What is the ideal fuel source? Will InterPlanetary travel require fundamentally new motion and energy technologies?
Is nuclear tech a realistic solution? Why?
Should space crafts be autonomous vehicles?
Will space cities be planetary establishments or will we live our lives in the confines of a space ship?
Where is the interplanetary dump?
How can we mitigate energy increases with our growing population?
How can we build sustainably energized outposts off-planet?