The tyranny of the rocket equation | Don Pettit | TEDxHouston 2013
17:30
Why We are Alone in the Galaxy | Marc Defant | TEDxUSF
16:42
Why the Moon | Don Pettit | TEDxNaperville
16:16
An astronaut's theory of how dinosaurs flew. | Don Pettit | TEDxNaperville
15:01
Have you ever imagined how interstellar travel could work? | Ryan Weed | TEDxDanubia
15:33
A better way to get to space: Dr. Michael Kelzenberg at TEDxWSU 2014
17:58
The Exploration and Colonization of Mars: Why Mars? Why Humans? | Dr. Joel Levine | TEDxRVA
11:44
Tara Rutley at TEDxHouston 2013
16:38