The countdown starts early. At the beginning of the selection to become an astronaut, or even as soon as the idea of ​​making the trip out of the atmosphere crosses the mind of the candidate. Everything is then linked, step by step, success after success, until the ultimate consecration when the contender is part of the team, the one that brings together extraordinary human beings, ready to follow the training mission for an adventure into space. Many months of intensive preparation, with a meticulously planned program, still separate the future hero from the last seconds of the countdown. The astronaut has to keep making progress every day. A few hours before they take off, the crew are placed into quarantine. On the launching ramp, curled up in their seats, they will be propelled into space within the deadline imposed by the launching procedure. In less than nine minutes, they will travel at an orbital speed of 28,000 km / h and will pass around the Earth 16 times each day. The real mission has just begun. Whether it is to ensure proper operation of the instruments, to repair them, to carry out scientific experiments, to communicate with Earth, to interact with their teammates, to sleep, to eat, the astronauts evolve at a certain pace, a pace which is imposed upon them by the trials of space. Although they are very busy, the return to Earth, close to where their loved ones reside can sometimes seem so far away. At each stage, even during an extravehicular exit or the return trip to Earth: is it possible for astronauts to challenge time?