Kennedy Space Center’s Carolina Franco, Ph.D., weighs one of the water tanks, recently returned to the center after remaining on the International Space Station for the past five years, in the Florida spaceport’s Neil Armstrong Operations and Checkout Building on Nov. 13, 2019. Two tanks containing water were first sent to the orbiting laboratory in 2014 to study slosh, or the movement of water, in a zero-gravity environment to help engineers predict the movement of propellant in rocket tanks. Kennedy’s Air and Water Revitalization lab is studying the water tanks to determine if there is, or was, any microbial growth within them. The results will help NASA determine whether clean water can be stored in space for long-duration missions, an essential component to keeping astronauts safe and healthy as the agency prepares for missions to the Moon and beyond to Mars.