The International Space Station residents were back at work Thursday after an ammonia leak indication sent the crew over to the Russian segment. Flight controllers determined there was no leak and NASA managers allowed the crew to resume normal activities and open the U.S. segment back up.

This week, the orbital residents kicked off several new experiments delivered Monday morning aboard the SpaceX Dragon commercial cargo craft. Italian astronaut Samantha Cristoforetti worked in Japan’s Kibo lab module feeding fruit flies for an experiment that will observe how long-term microgravity affects the immune system. NASA astronaut Terry Virts set up bacteria kits inside the Destiny lab’s Microgravity Science Glovebox for an experiment that explores the risk of infectious disease in space.

› Read more about the Fruit Fly Lab-01 experiment

› Read more about the Micro-5 experiment