Quote

Mars is a long ways away. The moon is only 240,000 miles, but Mars is in the millions. It's too risky without spending more time going to the moon.

Back in the days of Apollo, sending humans to the moon was the only viable way to get the scientific data we wanted. But now, with our computer and robotics technology, there's very little an astronaut can do on Mars that a well-designed rover can't.

We like to talk about pioneering Mars rather than just exploring Mars, because once we get to Mars, we will set up some sort of permanent presence.

Let's not spend resources that we don't need to be sending astronauts back to the moon. Let's not spend expensive resources on bringing people who have reached Mars back again. Prepare them to become a growing colony.

If NASA is to reach beyond the Moon and someday reach Mars, it must be relieved of the burden of launching people and cargo to low earth orbit. To do that, we must invest more in commercial spaceflight.

Mars is far more attractive as an outpost colony for earthlings than the moon is.

My view is that we should go back to the moon, build up the infrastructure to make flights there commonplace - be comfortable with it - then use that infrastructure to expand and go to Mars.

Is a one-way trip to Mars ever really seriously going to happen? Surely that's morally reprehensible. However old people are, however much they say they want to go on a one-way mission, people should be thinking about the possibility of returning.

When you go to Mars, you need to have made the decision that you're there permanently. The more people we have there, the more it can become a sustaining environment. Except for very rare exceptions, the people who go to Mars shouldn't be coming back. Once you get on the surface, you're there.