Nick Patrick is a British-born astronaut working in the Johnson Space Centre, Houston. He has worked on the Shuttle and helped to prepare the International Space Station. A keen diver Nick has also spent time in Project NEEMO - an underwater habitat used by NASA to research ways to keep astronauts alive. Nick loves his job and talks about some of his most exciting moments - takeoff and weightlessness in this interview.

So, Nick, what does an astronaut actually do?

The job of an astronaut is mostly to train for space flights and then to fly in space. It's a very busy job but between space flights when you're not actually training you can have another job too - an engineering job. Before I joined NASA I was a mechanical and aeronautical engineer and so my technical job between my last flight assignment and my next one is to follow the design and development of NASA's next spacecraft the Orion.

I love the variety of my work. I get to train with some very interesting people doing very difficult, challenging things. I occasionally get to go to exotic places like space and I once spent 10 days living under water as part of my training!

The training to be an astronaut is so interesting, we get to do fascinating things - you get to fly space simulators, we get to train in the neutral buoyancy lab in a 40ft deep swimming pool - the largest swimming pool in the world - in which we can float around as if we are weightless.

What is the most exciting thing you’ve ever done?

My most exciting event in my career so far has probably been the launch of my mission in December 2006. We were on board the space craft Discovery and we'd been sitting on the launch pad for the second launch attempt for three hours.
To watch the clock count down from 10 seconds to 0 after what for me was then 8 years of training was probably the most exciting moment of my life! This is then followed by the incredible experience of launch and 8.5 minutes of being thrust back into your seat followed by complete weightlessness - that was amazing!

They try to simulate this before hand and it is very helpful but its nothing like the real thing! You can get into a centrifuge and you can experience what we call the G-profile - the acceleration versus time of an entire launch. Alternatively you can get into a flight simulator and flick all the appropriate switches for the 8.5 minutes of a launch. But you can't put those two things together - the only place these all come together is in the space shuttle at launch and that's what makes it so exciting.

So what’s left after that experience?

I would love to be involved in a geological discovery or a biological discovery on a different planet. I would love to be involved in discovering some of the geological processes that take place on Mars and discovery what happened to its climate, which we believe at once contained a fair amount of liquid water.

Manned spaceflight isn't going to find everything unfortunately because some of it is so far away and we just can't get there, like this newly discovered planet 'Gliese 581' which orbits in the so called 'Goldilocks' zone. Gliese 581 is 20.5 light years away - so its not something humans are going to visit in the foreseeable future! The Goldilocks zone is fascinating because its a zone where the temperature is just right - it's not too close to the sun so the water would be boiled off and its not too far away so the water would all be frozen ice.

This planet is going round just far enough away from the sun that water would be, we think, liquid all of the time and that means its possible you could have the kind of life we have here on earth.

Do you think we will ever be able to meet any people (if they exist!) on Gliese 581?

It is possible to communicate to a planet this far away, but you need to wait for a really long tome for the message to get there and then get back. To send a message and receive a reply takes 41 years and that's assuming that they answer straight away and of course assuming that they are smart enough to be listening and able to think of an answer anyway!

There is a project called SETI (Search for Extra-Terrestrial Intelligence) that is actively listening to signals from many quadrants of the sky to see if they can hear radio broadcasts. Maybe they are trying to contact us even now!

You have some children, what do you hope for them?

I want to make sure my kids take the same kind of interest in science and technology that I did as a youngster. It would trouble me a lot if my kids weren't interested in science, I would be very surprised too! My kids are fairly mechanically inclined and interested in aeroplanes and construction but they are very young.

If they really showed no interest later on I would try to help them find, not so much a different subject, but a better reason to like the technical subjects. I think these are such an important foundation for anything in life you want to do. Even if you want to be a lawyer if you can understand engineering it opens up branches of the law that many people aren't familiar with it, like patent law.