The main toilet [has broken down](http://news.bbc.co.uk/2/hi/science/nature/8158350.stm) on the International Space Station (ISS), currently home to a record 13 astronauts.

Mission Control told the crew to hang an “out of service” sign until the toilet can be fixed. ISS residents are using a back-up toilet in the Russian part of the station.

If repairs fail, Apollo-era urine collection bags are on hand, Nasa said.