ASTRONAUT Tim Peake has sent a birthday message to his wife from space on Chris Evans's Radio 2 breakfast show.

Peake described his wife, Rebecca, as the "most amazing person I know" and said she "is an incredible mum to our two boys, I love her to bits."

He ended telling Evans: "She listens to your show so she'll be thrilled to hear this."

The British astronaut answered questions from Radio 2 listeners from aboard the International Space Station (ISS) during the show.

He said: "Sometimes it feels pretty normal until you look out the window and you're reminded of what a unique situation it is and how bizarre it is to be up here watching the earth go by, and it goes by so quickly. We're doing 17 and a half thousand miles per hour."

One listener, Adam from Swindon, wanted to know what space smelt like, and said he would "like it to smell a bit like Swindon", which made Major Peake chuckle before explaining they only get to "smell space" when people come in from a space walk.

"We open up the airlock, we kind of all jump in and get the first smell of space and really, it almost smells like a metallic, burnt smell," he said. "I actually think it's off-gassing or ionisation from the excessive heat that comes from the sun when you're out on a space walk."

Asked by a listener named Jackie if he was now the "king of the power nap" he said he wished he could manage a power nap but was being kept busy.

"But I do sleep pretty well, I'm tired by the end of the day," he said.

The 43-year-old from Chichester, became the first British astronaut to carry out a space walk earlier this year and is carrying out a number of experiments while aboard the ISS.

Major Peake also revealed that Sunday was his day off, normally spent by "chilling" and watching movies, having meals with the rest of the crew and making phone calls to friends and family back on earth.

When quizzed about what he was going to miss the most when he came back to earth he said it would definitely be weightlessness.

He said: "Because it is just so much fun being able to throw yourself around in all orientations, there's no up or down and you can move around pretty quickly and pretty efficiently."

The quirkiest question came from a listener named Adam, who asked: "With gravity not around, is there potential for the ageing process to be put on hold and if so, how are your wrinkles doing?"

Major Peake said: "You know wrinkles, varicose veins, space is great for that kind of thing, it gets rid of them all, but actually in terms of the ageing process, we accelerate unfortunately, so we're probably ageing by quite a few years by being up here just for six months."