In the experiment, detailed in PLOS Biology, the team incubated specimens of common lab bacteriophage T7 alongside its foe, Escherichia coli bacteria, for varying durations. They ran the same experiment on Earth and in space; the terrestrially reared viruses infected bacteria within two to four hours, but those in space took more than four hours to breach bacteria’s defenses. The infection took longer in orbit because microgravity is an unfamiliar stressor to which both microbes must adapt, the researchers suggest.