On July 8, at approximately 11:26 am EDT, the space shuttle Atlantis will streak skyward from the Kennedy Space Center's launch pad 39A, for one last mission.

Recent research aboard the space shuttle is giving scientists a better understanding of how infectious disease occurs in space and could someday improve astronaut health and provide novel treatments for people on Earth.

The cells and tissues in our bodies grow, develop and interact in a highly complex, three-dimensional world. Likewise, the various microbial pathogens that invade our bodies and cause infectious disease interact with this complex 3-D tissue milieu.

In a first-of-its-kind experiment, the unique conditions of spaceflight will be used to examine how cells remain healthy or succumb to disease, particularly in the face of stress or damage.

Researchers have been asking themselves this question ever since Salmonella bacteria grown on board the space shuttle returned to Earth 3 to 7 times more virulent than Salmonella grown on the ground under otherwise identical conditions.