• I don't think there's anybody with access to television who doesn't know my guest this week -- astronaut Sunita Williams. Welcome to Walk the Talk, in Delhi, right next to the module in which our astronaut, Rakesh Sharma, returned.

Thank you. I had the pleasure of meeting him in Hyderabad. This is quite a different capsule from the space shuttle that I used. It's just amazing to go to space.

• You took space walks on 195 days -- more than 22 hours altogether. That's a record for a woman astronaut.

That was the time when time flew past. The 195 days flew by, literally. We had so much to do. We were in the middle of the construction of the International Space Station (ISS) and that's why we had so many space walks. I was up there changing the temporary electrical and heating systems.

• I thought I'd come to that a little later. But you started this whole business of setting up a space station. I know you admire John Young. In the Apollo 16 mission, he walked on the moon and he inspired you. I believe you listened to him, and he always said that we can't carry on being a one-planet species and we need to fix that.

Exactly. The space station is just a stepping-stone. It's a laboratory, a collaborative work, in which people from countries across the world try to help understand what it is like to live in space for a long time. We can use that laboratory to help and develop materials and new flight control systems, for example, to see how you can go to the moon and, hopefully, on to Mars.

... contd.