Navigating space is no longer a privilege reserved for professional astronauts. This new kind of travel or exploration is increasingly expanding to civilians. The latter, however, may come to the mission in space without having received a minimum of training or acclimatization to extreme environments, as space itself would require. Now a new study led by Prof. Gerardo Bosco of the Department of Biomedical Sciences at the University of Padua, and Prof. Mrakic-Sposta of the CNR in Milan, and conducted in three Italian Air Force pilots who for the first time made a commercial suborbital flight, known as Galaxy 01, sheds new light on the changes in relevant biological parameters that astronauts may experience during, or rather upon re-entry to Earth. By resorting to very innovative and user-friendly techniques such as taking a saliva sample through a small salivette, Bosco, Mrakic-Sposta and colleagues have shown that even a rather short stay in space (such as the approximately 60 minutes of the Galaxy 01 mission) is sufficient, once back on the ground, to alter levels of molecules essential for controlling stress response or cognitive abilities. "We recorded a marked decrease in circulating levels of dopamine, which is implicated in the control of voluntary movement and emotional responses, accompanied by an increase in Brain-Derived Neurotrophic Factor (BDNF), a protein that presides over the control of nerve cell development, their maintenance and functioning, especially under stress conditions, and communication between nerve cells themselves," Bosco explains. "These alterations suggest an initial stress response. In fact, these alterations were also accompanied by a significant increase in cortisol levels, which is a hormone typically released in all those conditions characterized by fatigue, tension and physical and/or mental exhaustion".