The Unconventional Realities of Astronaut Training
The public image of astronaut training is one of heroic figures in gleaming white suits, pilots spinning in high-G centrifuges, and engineers solving complex equations. This picture is not wrong, but it’s fundamentally incomplete. The process of preparing a human being to leave Earth is a bizarre, grueling, and deeply strange endeavor. It involves re-wiring the body to function in an environment it never evolved for, all while breaking down the mind’s dependencies on the familiar comforts of our planet – like gravity, fresh air, and the ability to walk away from an annoying coworker.
The training regimen, developed over decades of hard-learned lessons by space agencies like NASA, Roscosmos, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA), is a gauntlet. It stretches far beyond physics and engineering. It’s a curriculum of survival, psychological endurance, and surprisingly mundane, awkward tasks. This article explores the stranger side of becoming an astronaut, the training that happens far from the popular imagination.
Simulating the Unsimulatable
Space is defined by its alien physics. The two most jarring are the crushing forces of launch and the perpetual freefall of orbit. Astronauts can’t just show up and experience these for the first time. They must be conditioned, and the simulations on Earth are intense physical and psychological ordeals.
The Vomit Comet
The only way to experience true microgravity on Earth, outside of a brief drop tower, is by falling. To do this in a controlled way, agencies use a specially modified aircraft, like NASA‘s former KC-135 or its current “Weightless Wonder” aircraft. The plane performs a maneuver called parabolic flight.
It’s not a gentle ride. The aircraft climbs at a steep 45-degree angle, pushing passengers into their seats with a force of about 1.8 Gs (1.8 times their body weight). Then, the pilots “push over” the top of the arc, effectively throwing the plane and everyone inside it into a controlled fall. For about 20 to 25 seconds, the occupants are in freefall, floating weightlessly inside the padded fuselage. The plane then pulls out of the dive, again subjecting the occupants to high G-forces, before immediately climbing to do it all over again.
A typical training flight repeats this maneuver 40 to 60 times. The “Vomit Comet” nickname is not an exaggeration. The constant, rapid transition from high-G to zero-G and back wreaks havoc on the human vestibular system – the inner ear’s balance mechanism. Motion sickness is extremely common, even for seasoned test pilots.
The strange fact here isn’t just the nausea; it’s that astronauts are expected to work through it. They aren’t on a joyride. They are tasked with performing delicate procedures: practicing with medical equipment, testing repair techniques on a floating panel, or simply attempting to put on a spacesuit. They learn to orient themselves without an “up” or “down” and to control their movements precisely, all while their body is screaming in protest. They must learn to “fly” their own bodies with tiny, precise movements, as pushing off a wall too hard will send them careening uncontrollably.
The World’s Deepest Pool
While the Vomit Comet provides brief moments of true weightlessness, it’s useless for practicing long, complex tasks like a spacewalk (EVA). For that, NASA uses the Neutral Buoyancy Laboratory (NBL) at the Johnson Space Center in Houston, Texas.
This is not a swimming pool; it’s an indoor ocean. It holds 6.2 million gallons of water and contains a full-scale, high-fidelity mockup of the entire International Space Station (ISS).
To simulate the weightlessness of an EVA, an astronaut is put into a full spacesuit, which is then carefully weighted and given flotation devices by a team of support divers. The goal is “neutral buoyancy,” a state where the astronaut neither sinks nor floats. They are suspended in the middle of the water, much like they will be suspended in the vacuum of space.
The strangeness here is the sheer endurance required. A typical EVA on the ISS lasts six to eight hours. Because working underwater is exhausting and slow, training runs are just as long. Astronauts will spend an entire workday submerged, meticulously practicing a single repair task, like replacing a battery unit or routing a cable.
This training is physically punishing in unexpected ways. The spacesuit gloves are pressurized and stiff. After hours of gripping tools and bolts, astronauts emerge with their hands raw, blistered, and swollen, a condition they call “sausage fingers.” They also face a real risk of decompression sickness, or “the bends,” just like deep-sea divers.
Furthermore, each training astronaut is shadowed by a team of scuba divers who act as safety monitors, camera operators, and stagehands, handing them the correct tools. The astronaut is alone in their helmet, communicating only by radio, executing a complex ballet in slow motion, all while fighting the simple drag of the water.
The Human Centrifuge
The G-force centrifuge is the most iconic piece of astronaut training hardware. It’s a machine designed to simulate the crushing acceleration of launch and the fiery deceleration of re-entry. Trainees are strapped into a capsule at the end of a long rotating arm and spun at high speed.
The experience is significantly unsettling. As the G-forces build, the astronaut’s body becomes impossibly heavy. Their 10-pound arm now feels like it weighs 50 or 80 pounds, making it a Herculean effort to simply reach a switch on the control panel. Breathing becomes a conscious, laborious act as the force compresses their chest, a feeling often compared to having a small car parked on their sternum.
The primary challenge is physiological. The G-forces pull blood away from the brain and down toward the feet. This leads to a predictable sequence of symptoms. First, vision loses color (“grey-out”). Then, it narrows into tunnel vision. If the G-load continues or the astronaut fails to counter it, the result is G-LOC: G-induced Loss of Consciousness.
A strange part of this training is learning the “AGSM” or Anti-G Straining Maneuver. This is a coordinated technique of tensing the muscles in the legs, abdomen, and buttocks, combined with a specific breathing pattern, to physically squeeze blood back up into the brain. Astronauts must train their bodies to do this instinctively, all while trying to monitor their (simulated) spacecraft controls. They are training not just to endure the ride, but to remain functional and clear-headed while their body is on the verge of blacking out.
The Psychological Gauntlet
The physical challenges are daunting, but the human mind is often the weakest link on a long-duration space mission. Space is not just physically distant; it’s significantly, unnervingly isolated. Training astronauts to cope with this isolation – and with each other – is one of the stranger and more personal aspects of their preparation.
Living in a Can
To prepare for a multi-year mission to Mars, agencies can’t just rely on theory. They must run full-scale simulations. These are experiments in extreme isolation. Projects like the Mars-500 program, a joint venture between Russia, the ESA, and China, locked a six-man crew inside a windowless, sealed habitat in Moscow for 520 days – the time it would take to fly to Mars, “land” for 30 days, and fly back.
NASA conducts similar missions at its HERA (Human Exploration Research Analog) facility. Crews are sealed inside a small, multi-level habitat for weeks or months at a time, performing mission tasks and living in close quarters.
The strangeness is the engineered psychological stress. The crews eat freeze-dried space food, follow a rigid schedule, and have their every move and conversation monitored. Mission control intentionally introduces problems: equipment “breaks,” emergencies arise, and tasks are changed without warning.
The most bizarre element is the simulated communication delay. On a real Mars mission, the distance means radio signals can take up to 20 minutes to travel one way. This makes real-time conversation impossible. In the HERA and Mars-500 habitats, this delay is built in. A crew member sending a message to “Houston” can’t expect a reply for 40 minutes. This severs the psychological tether to Earth, forcing the crew to become completely autonomous and self-reliant. It’s a test of “expeditionary behavior”: can you remain a functional, helpful, and polite team member when you are stressed, tired, and have no escape from the same few faces for months on end?
Sensory Deprivation
While isolation chambers test social dynamics, other training tests the mind’s response to the void. Space is a sensory deprivation tank. Outside the window is an unchanging blackness. Inside is the constant, monotonous hum of air filters and electronics.
To test this, astronauts are sometimes placed in sensory deprivation chambers or flotation tanks. In total darkness and silence, floating in body-temperature saltwater, all external stimuli are removed. The test is to see how the mind reacts. Some people find it calming, but for others, the lack of input can be distressing, even leading to mild hallucinations.
This training helps astronauts – and the psychologists screening them – understand their own mental baseline. It prepares them for the long, uneventful “cruise” phases of a mission. The challenge of spaceflight isn’t just the moments of terror; it’s the long stretches of significant boredom and disconnection.
High-Stakes Conflict Resolution
In the early days of Project Mercury, astronauts were cut from the same cloth: male, military test pilots. Today, an ISS crew is a complex mix of international partners, scientists, engineers, and pilots. A NASA biologist may share quarters with a Roscosmos engineer and an ESA doctor.
Because of this, a huge part of training is dedicated to “soft skills” that become high-stakes in orbit. Astronauts are explicitly trained in conflict resolution, team communication, and cultural sensitivity. They participate in forced-proximity survival drills, like camping together on a glacier or living in an underwater habitat like NEMO (NASA Extreme Environment Mission Operations).
These exercises are designed to create friction points and then force the crew to work through them constructively. When you can’t “go for a walk” to cool off, a minor disagreement about housekeeping or task priority can fester and jeopardize the mission. Astronauts are taught to give and receive feedback in a structured, non-confrontational way, a skill that is arguably as important as knowing how to fly the spacecraft.
The Survivalist’s Handbook
A space mission has two points of extreme danger: the beginning and the end. Launch is a controlled explosion, and re-entry is a controlled crash. Astronaut training must account for what happens if that crash is uncontrolled.
Landing in Siberia (or the Ocean)
The Russian Soyuz capsule, which for decades was the only ride to and from the ISS, is designed to land on the flat, vast steppes of Kazakhstan. But it doesn’t always hit its target.
This reality is why all astronauts who fly on the Soyuz – including Americans, Europeans, and Canadians – must undergo extreme wilderness survival training with their Roscosmos colleagues.
The strangest and most grueling of these is the winter survival drill. A crew of three, dressed in their bulky launch-and-entry suits, is dropped by helicopter into the remote, snow-covered taiga forest of Siberia. Their “capsule” is a simulation, and they have only the emergency survival kit that is packed on the Soyuz. For two days and two nights, they must survive in sub-zero temperatures.
This training is a direct result of the Voskhod 2 mission in 1965. Cosmonauts Alexei Leonov and Pavel Belyayev’s capsule overshot its landing site by hundreds of miles, leaving them stranded in a forest full of wolves. Modern crews practice building a shelter from their parachute and tree branches, starting a fire (a difficult task in bulky, pressurized gloves), and rationing emergency supplies.
This isn’t the only scenario. Crews also practice sea survival, leaping from a mockup capsule into the Gulf of Mexico or the Black Sea. They must inflate a raft, manage seasickness (compounded by post-re-entry sickness), and practice being hoisted by a rescue helicopter. They also run drills for a desert landing, focusing on water discipline and using the parachute for shade.
Fire, Smoke, and Poison Air
Three emergencies are dreaded above all else on a space station: fire, depressurization, and a toxic atmosphere (like an ammonia leak from the cooling system). Training for these is a high-octane, panic-inducing simulation.
Fire in microgravity is especially strange. Flames don’t “rise” because there is no “up” for hot air to go. A fire burns in a sphere, and smoke doesn’t layer at the ceiling; it simply fills the module like a thick, choking fog.
To simulate this, trainers will fill an ISS mockup with thick, non-toxic theater smoke. Alarms blare, and the astronaut crew, wearing emergency masks, must “float” through the blinding smoke to find the source of the fire. They have to communicate, coordinate to find the right fire extinguisher (one for electrical fires, one for others), and perform the procedures to cut power and vent the smoke – all while their hearts are pounding.
Depressurization drills are a race against the clock. If the station is breached by a micrometeoroid, the air will rush out. The “time of useful consciousness” can be less than a minute. Astronauts practice hearing the tell-tale hissing sound, identifying which module is leaking (by watching air-flow indicators), and quickly sealing the hatches to isolate it. If the leak is in their own module, the drill is a frantic scramble to get into their Soyuz or Crew Dragon “lifeboat” before the pressure drops.
The Bizarre and the Mundane
Not all astronaut training is about high-stakes survival. Some of the strangest parts involve re-learning the most basic human functions, which are completely different without gravity.
The Art of the Space Toilet
Perhaps the most famously bizarre piece of training involves the space toilet. On Earth, gravity handles the “waste collection” process. In space, everything floats.
The space toilet, or Waste Collection System (WCS), is not a simple device. It’s a complex machine that uses airflow (suction) to pull waste away from the body. Using it correctly is a matter of sanitation and safety; escaped waste is a biohazard that can float into sensitive equipment or the crew’s breathing space.
To ensure astronauts know how to use it, they practice on a “positional trainer” on the ground. This is a mockup of the toilet seat with a camera inside the bowl and a light for alignment. Trainees must use this “potty trainer” to practice positioning themselves perfectly over the small opening, using a nearby monitor to check their alignment. It’s an awkward, slightly embarrassing, but absolutely necessary part of the curriculum.
Everyday Life Without Gravity
Almost every daily task must be re-learned.
- Eating: Food must be sticky, liquid (in pouches), or in bite-sized forms to prevent “crumbs.” Crumbs don’t fall to the floor; they float. They can be inhaled, get into an astronaut’s eye, or clog air filters. This is why tortillas are a spaceflight staple instead of bread. The Apollo program astronaut John Young famously smuggled a corned beef sandwich on board, and the resulting crumbs were a serious (though humorous in hindsight) concern.
- Hygiene: You can’t take a shower. Water doesn’t flow; it clings to the skin due to surface tension. Astronauts “shower” with a small amount of water on a washcloth. They use no-rinse shampoo, toweling their hair “dry.” When brushing teeth, they must swallow the toothpaste or spit it into a towel.
- Grooming: Shaving requires a razor connected to a vacuum to suck up the whiskers. Cutting fingernails is a major operation, usually done over an air vent to catch the flying clippings.
Everyone is a Part-Time Doctor
There is very limited medical support in orbit. While one crew member is usually the designated Crew Medical Officer (CMO), they can’t operate on themselves. What if the CMO is the one who gets sick or injured?
For this reason, all astronauts receive extensive medical training. This goes far beyond basic first aid. They practice on high-fidelity medical mannequins that can simulate breathing, bleeding, and cardiac arrest.
The stranger fact is that they practice invasive procedures on each other. Astronauts learn to draw blood from their crewmates’ arms, give IVs, perform sutures (stitches) on pads of synthetic skin, and even use dental equipment to place temporary fillings or, if necessary, pull a tooth. They must be prepared to be medical assistants in a complex emergency, all while floating in microgravity, where blood forms floating spheres and all their tools must be tethered.
The Unexpected Curriculum
Finally, there is a set of skills required of astronauts that seem to have nothing to do with spaceflight, yet are fundamental to the job.
Learning Russian
For more than two decades, a non-negotiable part of every NASA, ESA, CSA, and JAXA astronaut’s training was learning Russian. With the retirement of the Space Shuttle in 2011, the only way to the ISS was the Russian Soyuz.
This isn’t conversational Russian. Astronauts must become fluent in high-stakes, technical language. The controls on the Soyuz are labeled in Russian. Communications with Russian Mission Control (TsUP) are in Russian. All emergency procedures are in Russian.
This requires an intensive, multi-year language immersion program. Astronauts and their families often move to Star City, Russia, the home of the Roscosmos training center, to live and breathe the language. For many astronauts, who often have backgrounds in engineering or medicine, mastering a complex new language is one of the most difficult academic challenges they face. While the advent of SpaceX‘s Crew Dragon has provided an American alternative, the ISS itself is a joint facility, and Russian remains a required skill.
Geology Field Trips
During the Apollo program, NASA faced a unique problem. They were about to send test pilots to the Moon, an untouched geological treasure chest. But these pilots didn’t know the first thing about rocks.
So, NASA turned its elite aviators into field geologists. This was a strange and sometimes unwelcome diversion for the pilots. They were sent on field trips to places on Earth that resembled the lunar landscape, like Meteor Crater in Arizona, volcanic fields in Iceland, and other impact sites.
They were taught by leading geologists how to identify different rock formations, how to describe them verbally for the team back on Earth, and how to select the most scientifically valuable samples to bring home. This training was essential. The Apollo missions returned 382 kilograms (842 pounds) of lunar material, and the astronauts had to be the on-site scientists making the choices. This training, which fused piloting with field science, is being revived for the crews of the Artemis program, who will be the next to walk on the Moon.
Flying Supersonic Jets
Even astronauts who are not pilots must spend a significant amount of their training time flying NASA‘s two-seater T-38 Talon supersonic jets. This often seems strange, especially for “mission specialists” like scientists or doctors. The Space Shuttle is retired, and modern capsules like the Crew Dragon and Soyuz are largely automated.
The reason is not about learning to fly the spacecraft. It’s about mindset. The T-38 is a fast, complex, and unforgiving aircraft. Flying it forces astronauts to remain in a high-stakes environment where they must make rapid, correct decisions under pressure. It keeps their situational awareness sharp and their procedural discipline flawless. For two crew members flying together, it’s a powerful tool for building crew coordination and trust. It’s a way to keep an astronaut’s mind “on the edge,” preventing the complacency that can be lethal in space exploration.
Summary
Astronaut training is a testament to human adaptability. It’s a curriculum built from decades of failure and success, designed to take an ordinary person and prepare them for an extraordinary, and extraordinarily hostile, environment. The strange facts of this training – the “potty trainer,” the Siberian survival drills, the geology lessons, and the psychological isolation – are not arbitrary. Each one is a specific, practical solution to a problem that space poses. The training proves that the most complex component of any space mission is not the rocket, but the human being.
