Inside Astronaut Training: How Space Agencies and Commercial Companies Prepare Humans for the Final Frontier

When we think of astronauts, it is easy to imagine them only at the most dramatic moments: floating effortlessly in microgravity, walking across the International Space Station’s solar arrays, or strapping into a spacecraft moments before launch. Yet behind these images lies years of preparation, a meticulous training pipeline that transforms ordinary people - scientists, pilots, engineers, and now even civilians - into individuals capable of surviving and working in the most hostile environment humans have ever known. Astronaut training is not uniform across the world; NASA, ESA, Roscosmos, and the growing commercial space sector all approach it differently, shaped by history, culture, and the missions they are preparing for.

At NASA’s Johnson Space Center in Houston, astronaut candidates begin their journey with an intense two-year training program that is as much about shaping the mind as it is about conditioning the body. Candidates cycle between advanced scientific instruction, language courses, and physical training, but the heart of NASA training lies in the massive pool known as the Neutral Buoyancy Laboratory. This facility, which houses a full-scale underwater mockup of the International Space Station, is where astronauts learn the painstaking choreography of spacewalks. Hours underwater, encumbered by weighted suits that mimic the resistance of microgravity, teach them not only the mechanics of tools and tethers but also the patience to endure tasks that are mentally draining and physically exhausting. Beyond the pool, NASA trainees spend time in motion simulators that replicate the violent shaking of launch, in high-G centrifuges that expose them to the crushing forces of re-entry, and in classrooms where they memorise the countless systems of spacecraft they may one day fly.

Across the Atlantic, the European Space Agency shares many of the same foundations, but its training philosophy emphasises international collaboration. ESA astronauts in Cologne, Germany, train alongside NASA counterparts, and their programs include long rotations at facilities in Houston, Moscow, and Tokyo. A European astronaut might begin in the classroom learning orbital mechanics in Germany, spend months in Russia practicing Soyuz spacecraft operations in Star City, and then travel to Japan to master the systems of the Kibo module before ever flying in space. Language training is not optional but central: English and Russian remain the two operational languages of the International Space Station, so European astronauts must be fluent in both, switching between them seamlessly under stress. Where ESA particularly shines is in cross-cultural preparation; its astronauts are trained not only in science and engineering but in how to build trust and resolve conflict within multinational crews who must live together in isolation for months at a time.

In Russia, Roscosmos preserves a training culture rooted in the Soviet era, one that remains strikingly different from its American and European counterparts. At Star City, outside Moscow, cosmonauts are subjected to extreme endurance tests and survival training that reflect the hard pragmatism of Russian spaceflight. Since Soyuz spacecraft land unpredictably across the steppes of Kazakhstan, cosmonauts must prepare to endure days in the wilderness until recovery teams arrive. They spend weeks learning to build shelters, start fires, and hunt or fish for food in harsh conditions, sometimes even being dropped into forests in the middle of winter as part of training scenarios. This survival component, less emphasised at NASA or ESA, reflects the unique demands of Soyuz operations. Cosmonauts also train extensively in centrifuges that spin them to levels of acceleration few other astronauts experience, reinforcing Russia’s view that human endurance is as critical as technical skill. Their simulators are spartan, their drills repetitive, but the result is a kind of psychological toughness that has defined the Russian approach to human spaceflight for decades.

What is new and transforming astronaut training is the rise of commercial and private missions. Companies such as SpaceX, Axiom Space, and Blue Origin are now preparing crews that include not only career astronauts but also scientists, artists, and even paying tourists. These individuals do not undergo years of immersion in neutral buoyancy pools or Russian survival courses. Instead, their training is shorter, tailored to mission objectives, and heavily dependent on simulation. SpaceX astronauts, for instance, train in high-fidelity Dragon spacecraft simulators for hundreds of hours, drilling on manual controls, emergency procedures, and communication protocols. Axiom Space, which is planning private missions to the International Space Station, supplements this technical training with condensed versions of NASA’s instruction - including underwater exercises, medical simulations, and even cultural training to prepare private astronauts for life aboard the ISS alongside professional crews. The commercial model strips away much of the broader preparation that government agencies demand, focusing instead on ensuring safety, mission readiness, and baseline competency. Yet it raises a fascinating question: what does it mean to be an astronaut when the term now includes both seasoned pilots and civilian passengers?

Despite these differences, there are threads that unify astronaut training across institutions. All astronauts, whether selected by NASA or Roscosmos or trained by a private company, must learn to work in confined environments for extended periods of time. They must understand the physics of orbital flight and the delicate systems that keep them alive in the vacuum of space. They must be prepared for emergencies (fire, depressurization, toxic atmosphere leaks) that could demand split-second action and calm under pressure. Perhaps most importantly, they must learn to function as part of a crew, subordinating ego to teamwork, because no one survives space alone.

Looking ahead, astronaut training will continue to evolve as missions extend beyond low Earth orbit. Preparing astronauts for the Artemis program and eventual Mars expeditions requires new skills: long-duration autonomy, radiation protection, field geology, and even surgical medical procedures performed in isolation. Space agencies are already experimenting with analog missions in remote deserts, caves, and polar regions to simulate the psychological and operational challenges of deep space. Meanwhile, commercial providers are reshaping the definition of astronaut itself, opening pathways for a much wider diversity of people to experience space.

Yours truly,

Contributing writer - Riyam Ojaimi

Founder & CEO, Executive Team

Sources:

NASA. “Astronaut Selection and Training.” https://www.nasa.gov/humans-in-space/astronauts/astronaut-selection-program/

European Space Agency. “Basic Training.” https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Astronauts/Basic_training

The Aerospace Corporation. “Framing the Future of Commercial Human Spaceflight Environment.”

https://aerospace.org/article/framing-future-commercial-human-spaceflight-environment