“We’ve got to restore American ability to transport astronauts with domestic vehicles, and that’s what we hope to do in about two years.
“The next step beyond that is to maybe send people beyond low Earth orbit to a loop around the Moon, possibly land on the Moon — although I’m not super interested in the Moon personally because obviously we’ve done that and we know we can — but maybe just to prove the capability.
“Then we need to develop a much larger vehicle which would be sort of what I call a large colonial transport system. This would really be — we’re talking about rockets on a scale, a bigger scale than has ever been done before, that make the Apollo Moon rocket look small. And they would have to launch very frequently as well.
“That’s what’s needed in order to send millions of people and millions of tons of cargo to Mars, which is the minimum level to have a self-sustaining civilization on Mars.
“We might be able to complete that [rocket] in about 10 or 12 years, and hopefully the first people we’d send to Mars would be around the middle of the next decade.”