On board the final launch of the space shuttle Endeavour is baby squid. 

This is not because the astronauts want a change in their menu: the squid could help us understand how "good" bacteria behave in the microgravity of space. 

We already know that disease microbes grow faster and become more virulent if they are sent into space. In 2006 Salmonella bacteria were sent up on a space shuttle, and when they returned to Earth they were almost three times as likely to kill mice as normal (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0707155104). Escherichia coli also changes its behaviour.

These studies all focused on harmful bacteria. "This is the first to look at beneficial bacteria," Foster says.   

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