You can't 'control' a Mars mission from Earth. The Mars mission is going to have to be controlled by the people on Mars... There is just too much involved that is out of sight of Earth.
Chemical propulsion is obsolete to go anywhere other than the moon. Three days - that's acceptable. But for Mars, we need propulsion technologies to get us there in, say, 60 days - then spend whatever length of time we want to spend and return when we want to come home.
We're on the same radius from the Earth, and then we start to swing around to where we're ahead of them on the velocity vector, so we come in relative to the station from this forward velocity position and dock on to the forward end of the Lab.
Pulsars are in an ideal part of the universe to test Einstein's theory of relativity - so far, it's holding up well. They may even one day act as navigational beacons for spacecraft. I'll never tire of them; they really are the most extraordinary objects.
I definitely knew how to fly. That's something you don't forget. One spaceship is pretty much like another when it comes to flying.
If you're in space on the way to Mars, and a conflict develops... you can't turn around and go back, because Earth is already gone on its orbit.
What's aero braking? That's a way to use the gravity and upper atmosphere of Earth to sling shot a ship out either deeper into space, or slow it down to be 'captured' by Earth's gravity.
Houston, that may have seemed like a very long final phase. The autotargeting was taking us right into a ... crater, with a large number of big boulders and rocks ... and it required ... flying manually over the rock field to find a reasonably good area.
The g-forces increased and I wasn't able to continue to hold the camera against the window, so I had to lay it back against my chest, but still continued to photograph the re-entry until there was no more unusual visual effects of the energy in the atmosphere. And it was very comforting to understand that the people in Houston, the controllers, had very high confidence that we were on the right path.
To try to really land a spacecraft really on another world is really difficult, and if we lose that ability, it's going to be heartbreaking.
For here, am I sitting in a tin can, far above the world. Planet Earth is blue, and there's nothing I can do... Though I'm past one hundred thousand miles, I'm feeling very still - and I think my spaceship knows which way to go. Tell my wife I love her very much.
There is a project that's underway called the interplanetary Internet. It's in operation between Earth and Mars. It's operating on the International Space Station. It's part of the spacecraft that's in orbit around the Sun that's rendezvoused with two planets.
If the guidance failed or started to stray or went somewhere we didn't like or the ground didn't like, I could flip a switch, and I could control seven, over seven and a half million pounds of thrust with this handle and fly the thing to the Moon myself.
I think I set myself on a course to become a scientist around about the time that Carl Sagan's 'Cosmos' series was on television, and there really was no going back for me at that point, and then I went on to study space science and then get my Ph.D., then go aboard and work in the European Space Agency.
Space has not changed but technology has, in many cases, improved dramatically. A good example is digital technology where today's cell phones are far more powerful than the computers on the Apollo Command Module and Lunar Module that we used to navigate to the moon and operate all the spacecraft control systems.
Well, the coolest thing I have seen so far, in terms of, like, me being an astronaut and seeing something unusual, was the rendezvous, the docking of a Progress spaceship.
I study orbital dynamics as a hobby. My idea of a good time is sitting down and drawing on that knowledge to imagine a space mission from beginning to end, getting as many details right as I can.
