Propulsion is still the key to improving transportation in space and on earth

Question: What scientific breakthrough needs to take place to revolutionize travel?

Leroy Chiao: Well, it's always been – the big breakthroughs in transportation have always been in propulsion. However you're going to get the vehicle going. From the ground transportation side, you know horse and buggies gave way to steam engines and locomotives to the first practical small gasoline engine and the cars, the first cars, steam ships, sailing ships gave way to steam ships, which gave way to diesel and nuclear powered vessels. The airplane started out as these tiny little engines turning propellers to turbo props and modern propeller airplanes to the jet engine, the advent of the jet engine, turbo jets, and then to turbo fans, which were efficient enough to allow the air transportation system as it is today to develop.

Same with rockets. Rockets have remained fundamentally unchanged, except for a few exceptions for the last almost 50 years. So, for there to be a fundamental shift in rocketry and getting into space, there almost has to be a breakthrough in propulsion. Either in how to bring the price down, or how to more efficiently get people up into space and that's, as we talked about earlier, the key barrier is the expense of a rocket.

Question: What innovation is needed in terms of harnessing energy?

Leroy Chiao: Well, it's physics. It's a matter of getting enough energy to get off the planet and into lower Earth orbit. It takes a fixed amount of energy to do that per mass of payload. And so, that part is fixed, but how you do that, how do you get the energy, how do you extract it from a chemical propulsion you are using, or if you're coming up with a whole new way of doing it.

The neatest thing about research and science is we don't necessarily know what's going to come down the pike. We think we know what we're working on. Oftentimes, discoveries are made when you're trying to discover something else. You end up accidentally discovering a different thing. So, one of those things might happen that enable us to have more efficient rockets. It’s hard for me to kind of guess what that might be.

Recorded on December 16, 2009