Alexander Voorhies (Ph.D. 2014, Greg Dick) is currently working as a Post Doctoral Fellow at the J. Craig Venter Institute tracking changes to the microbes and viruses that live in and around astronauts spending six months to one year at the International Space Station (ISS). During a mission to space, astronauts are subject to many stressful conditions (g-forces, radiation, microgravity, anxiety, etc.) that can have a negative impact on their health. Several studies have demonstrated that space travel affects the astronauts’ immune systems and have shown some evidence suggesting that changes in their microbiomes occur as well. Because the human microbiome plays a key role in human health, it is important to assess the effect of long duration space exploration on the microbial population that inhabits the human body. This study will carry out a thorough evaluation of how long-term space travel impacts the human microbiome and ultimately human health, and it will form the basis for further studies towards the design of therapies to mitigate any microbiome changes or related health issues found as a result of this project. Therefore, this study has the potential to lower the risks to human health for future space explorations.