Virtual Reality On-Board Training (VR-OBT) is a technology demonstration led by ESA and supported by the German Space Agency DLR. It seeks effective ways to deliver on-board training to astronauts through virtual reality. ESA uses virtual reality to train astronauts on the ground and is currently used for training astronauts on the European Life Support Rack (LSR) installed on the Space Station. LSR contains ESA’s Advanced Closed Loop System which filters the air on the Space Station for CO2, and through further processing, creates clean oxygen for the astronauts to breathe and water to be re-used in the life support system.