Nowadays astronauts normally spend six months in space at any one time although some missions can last longer. The record for the longest single spaceflight is 437 days and 18 hours. Theoretically it would be possible for us to live in space for much longer provided we developed a spacecraft with all the provisions to support life. If we became almost perfectly efficient at recycling resources such as oxygen, water and food it might be possible to live in space indefinitely.
However, we currently do not know the full long-term effects of living in space on the human body. Hopefully future missions and experiments with astronauts will help us find out more.
Got a question for us? Send it into firstname.lastname@example.org and you could see it featured in All About Space – available every month for just £3.99. Alternatively you can subscribe here for a fraction of the price!