Japanese astronaut Furukawa Satoshi, who is aboard the International Space Station, spoke to reporters on Thursday, Japan time, about his mission. He suggested humans have a marvelous ability to adapt to space travel.

Furukawa said this is his 19th day in space and he is doing fine.

He said, "I feel that I have gotten accustomed to this environment more quickly than in my previous stay at the ISS."

Furukawa was a surgeon before becoming an astronaut. The 59-year-old made his first trip to space in 2011 on board a Russian Soyuz spacecraft. He said he suffered from space sickness on that flight.

This time Furukawa said, "I've hardly had any space sickness. The last time I suffered from the illness for about a week. So I'm surprised that I've been able to adjust to this environment pretty quickly."

This is Furukawa's second time on the ISS. He says the food and daily essentials have greatly improved since his first stay in 2011.

He also said, " The quality of life in space is much better than that of my last flight and it's very comfortable here. I will work hard on the ISS with other crewmembers and ground staff."

Furukawa's mission theme is "there are answers which can be found only in space."

During his 6-month stay, he will conduct various experiments, including a project to improve equipment that purifies urine to turn it into drinking water.