ESA astronaut Alexander Gerst and his five colleagues on the International Space Station spend many hours running experiments but their orbital home needs care and attention too.

Here Alexander is analysing a water pump in Europe's Columbus laboratory to make sure that it is working correctly. A number of water pumps work continuously to keep the module and its experiments at the correct temperature. Making sure they work well is an unglamorous task but a vital one.

Read more about the Blue Dot mission:
http://www.esa.int/bluedot