1 From the Department of Anaesthesiology and Intensive Care Medicine, Merheim Medical Center, Hospitals of Cologne, University of Witten/Herdecke (UL), German Aerospace Center (DLR), Institute of Aerospace Medicine (UL, FH, JJ, JT), Department of Internal Medicine III, University of Cologne, Cologne, Germany (FH, HR), Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA (VGZ, BDL), Department of Anaesthesiology, Medical Faculty, RWTH Aachen University, Aachen, Germany (MH), Department of Internal Medicine (HS), Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center (HS), Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas, USA (BDL) and Chair of Aerospace Medicine, University of Cologne, Cologne, Germany (JJ).