ESA Explores is a podcast from inside ESA, and the episodes gathered here stay close to one subject: how people are turned into astronauts. A string of them carries titles beginning 'ESA's Astronaut Reserve: Astro Chat with', each followed by a guest's name. In those, host Laura Zurmühlen talks with members of ESA's Astronaut Reserve at the European Astronaut Center in Cologne, Germany, during the first phase of their training. That phase covers spacecraft systems, robotics, scuba diving and survival. The pattern is simple: first where a trainee comes from, then how the training has felt so far. What makes it worth hearing is how different those starting points are. Carmen Possnig is a medical doctor and space physiologist who spent more than a year in Antarctica on research for ESA. She found the biology classes a little easier than the engineers in her group did, and she wishes she had taken the human behavior and teamwork lessons before going to Concordia. John McFall, a former Paralympic sprinter and trauma and orthopedic surgeon, is part of the FLY Project, where he is helping to open spaceflight to people with disabilities. He describes a block of reserve training that ran alongside basic training, including a module on human behavior and performance, and what he learned about everything a piece of hardware goes through before it flies. Meganne Christian, an industrial chemist who researches advanced materials for space and advises the UK Space Agency, remembers 100 days of darkness with a small team. Her 'pinch me' moments were getting her first flight suit and making her first dive in the neutral buoyancy facility. Arnaud Prost, an aviation engineer, recalls a winter survival exercise: a snow hole, a parachute for cover, nothing but a flight suit, a very long night, and a team where nobody complained. Sara García Alonso, a biotechnologist in cancer research and an advocate for science communication, has pipetted daily for more than twelve years and has given the others in her group a few pointers. She is drawn to space experiments in drug design, which sit close to her own work isolating proteins that are targets for diseases such as lung cancer. Beyond the reserve, ESA astronaut Pablo Álvarez Fernández from Spain, who joined the Corps in 2022 and has completed basic training, appears in 'Pablo Álvarez Fernández: Spacesuits, survival and spacewalk dreams'. That conversation was recorded in Cologne after his time at NASA in the US. He calls pool training both the best part and the hardest: around six hours in the water, where pressurized gloves make every movement a struggle. Two threads run through these conversations. Antarctica comes up more than once, and several guests treat teamwork as something the training deliberately works on. The mood is warm and enthusiastic, and the host keeps the questions personal. For the physical side of training, start with Pablo Álvarez Fernández. For how a scientist adjusts to the classroom, try Carmen Possnig or Sara García Alonso.