ESA astronaut Thomas Reiter was the first European on a long-duration mission to the International Space Station. In 2006 he spent over five months in space for the Astrolab mission.<br />One of the experiments for Astrolab was Leukin, an experiment to study how human immune system cells adapt to weightlessness. A batch of human immune cells was allowed to float in microgravity while another was held in a centrifuge to simulate gravity.<br />In this video Thomas is adding a chemical to the immune cells to make them think they are under attack. The process is performed in a portable glovebox for safety reasons. Nothing can escape the box and contaminate the International Space Station.<br />The cells are then injected with a fixative to create a snapshot of the cells activity.<br />The cells were stored in ESA's Minus Eighty-Degree Laboratory Freezer for analysis back on Earth where researchers have discovered that living in space weakens astronauts' immune systems.<br />By comparing the samples, researchers saw what was stopping the immune cells from working. A specific transmitter in the immune cells stops working in weightlessness.<br />The findings are providing clues on how to tackle diseases on Earth before symptoms appear.
