Nasa astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko are one third of the way through a record-breaking year-long mission aboard the International Space Station (ISS) and in an interview from space on Thursday (30 July) they said they are feeling good.

"I'm feeling great. I think 'Misha' is feeling great as well. I think we still have a lot of energy left in the tank so to speak," Kelly said.

This is the first time anyone has spent a year on the ISS, although four Soviet-era cosmonauts did that and more aboard the Mir space station. Scientists are trying to find out how the human body fares during longer stays in space.

"I personally don't feel claustrophobic but I do recognise there is a sense of a loss of freedom to kind of do what you chose. You have a very structured schedule and you follow that schedule very closely. If you wanted to deviate from it, you really don't have that capability. And I also get the sense that you don't have the capability to go outside and take a walk and put your feet in the grass, go swimming, take a shower. That's definitely recognised. So there are some hardships that we live with up here but, on the other hand, it's an amazing place, it's fascinating and it's a great experience," Kelly said.

Kelly says there are several ways to stay in touch with those on Earth − including telephone and email for friends and family and the internet that allows him to post photos on social media. "As far as the pictures and stuff I post, it's fun for me and I think people connect with things, with the Earth and things they can see and things that are beautiful," Kelly said.

He also says the crew is doing fine with their supplies, despite several failed attempts to send cargo to the station and he says it's great to have company at the space station. Three new crew members arrived 22 July 2015. They are veteran Russian cosmonaut Oleg Kononenko and rookie astronauts Kjell Lindgren with Nasa and Japan's Kimiya Yui.

"It's great having company and the other interesting thing about that is it's great sharing the experience with two people that have never flown in space before. Kjell Lindgren from Nasa and Kimiya Yui from the Japanese space agency. It's great seeing this place a little bit through their eyes and how magical a place it is. They've been on board a week now and they are doing absolutely great, performing like veterans, feeling great and it's great to share this experience with them," Kelly said.

Kornienko says he is looking forward to a planned spacewalk on 10 August for him and fellow cosmonaut Gennady Padalka to clean windows and collect an experiment.