"But I think talking about space with as many people as possible and relaying my experiences is my main mission for a while," she said.
Williams, 47, who holds the world record for the most spacewalk time - 50 hours 40 minutes - by a female astronaut, is in India on a week-long trip. "For me, it would be a dream to go back to the moon. It would be awesome to go to Mars, but I have a feeling that in my life as a professional astronaut, that might not happen," she said.
On Indo-US collaboration in space, she said, "I have been at the NASA. I have seen a growing relationship between the US and India. I think that's great. I have also seen the growing relationship between ISRO and NASA and that is also great." Asked if it gets lonely out there in space, she said, "No, it doesn't get lonely. There is enough connection to Earth that you don't really feel all alone. You can make phone calls to friends and family."