Get the Rockets Ready: What Is an Astronaut and How to Become One?
- 3 days ago
- 12 min read
Updated: 3 days ago
Astronauts—the ultimate space enthusiasts on a mission to explore the farthest reaches of the universe! I’m super excited to be writing a blog about this because experiencing space and floating in zero gravity is insanely fun! But is an astronaut’s job just observing on the space station, walking on the Moon, or prepping for a Mars mission? Absolutely not—like any career, astronauts have intense training, tough missions, and complex procedures.
For example, an astronaut who’s spent a long time in space—like me—might still feel weightless upon returning to Earth, let go of objects mid-air, have disrupted sleep, or even risk depression! In short, exploring the universe is seriously hard work. Now, let’s get back to the topic: what exactly is an astronaut, what do they do, how do they return to Earth, how do they live in space, and how can you become one? Let’s dive into this career in full!
Contents
What Is an Astronaut?
An astronaut—also called a space traveler or cosmonaut—is a professional trained to participate in space missions. Traditionally, astronauts are selected and trained by space agencies to serve as crew members or commanders on spacecraft. Their duties can include conducting scientific research, performing spacewalks, and operating spacecraft systems. Today, however, the term has expanded to include anyone traveling to space, from scientists and politicians to journalists and even tourists.
What Does Astronaut Mean?
The word “astronaut” literally means “star sailor.” Its origin comes from Greek: “astron” means “star” and “nautēs” means “sailor.” It passed into Latin as “astronauta” and then into English as “astronaut.”
What Do Astronauts Do?
Let’s break down the responsibilities of an astronaut:
They conduct scientific experiments that take advantage of the microgravity environment.
They study how space conditions affect various fields, including biology, physics, and human physiology.
They are responsible for piloting spacecraft and managing its systems.
Their duties include monitoring systems, troubleshooting issues, and coordinating mission objectives with mission control.
They perform spacewalks to deploy satellites or conduct scientific experiments outside the spacecraft.
They repair and maintain the spacecraft and its systems, acting as plumbers, electricians, and IT specialists in the confined space of the vessel.
To counteract the effects of microgravity on their bodies, astronauts exercise about 2.5 hours daily to maintain muscle strength and bone density.
They work closely with other crew members and ground control teams.
They participate in educational outreach programs to inspire future generations in science and space exploration.
Even after becoming astronauts, they continue learning new skills and staying updated on technological advancements related to their missions.
How Long Do Astronauts Stay in Space?
The average mission duration for astronauts aboard the International Space Station (ISS) is about six months (180 days). Depending on the mission, stays can range from a few days to several weeks or months, and sometimes even longer than six months. For example, NASA’s planned crewed Mars mission in the 2030s is expected to last more than a year.
Who is the Astronaut Who Spent the Longest Time in Space?
Russian cosmonaut Valeri Polyakov holds the record for the longest single spaceflight, spending 437 days and 18 hours (over 14 months) aboard the Mir space station in the mid-1990s.
How Do Astronauts Return from Space?
Astronauts depart the International Space Station (ISS) using a spacecraft such as SpaceX’s Crew Dragon or Russia’s Soyuz, ensuring that all systems are fully operational before beginning re-entry preparations.
The spacecraft performs orbital maneuvers to position for landing and re-enters Earth’s atmosphere at speeds exceeding 27,358 km/h. As it approaches, parachutes deploy at about 5.5 km altitude to slow the descent. Depending on the spacecraft, astronauts either splash down in the ocean or land on solid ground. After landing, recovery teams assist in retrieving the spacecraft, and medical checks are conducted to assess the astronauts’ health.
Changes Observed in Astronauts Returning from Space
Bone Density: In microgravity, the legs, hips, and spine do less work, so astronauts experience a decrease in bone density.
Muscle Loss: Earth’s gravity naturally stimulates muscles, but in space there’s no such force, so muscles aren’t required to “work,” leading to atrophy.
Physiological Adjustment: Adapting to microgravity takes time, and returning astronauts need to reacclimate to Earth’s gravity. They may experience dizziness, difficulty standing, walking, or seeing properly.
Eyes: The most common vision issues in space include flattening of the eyeball, optic disc edema, and other changes. Space-Associated Neuro-ocular Syndrome (SANS), which causes swelling at the back of the eye, is particularly prevalent.
Cardiovascular: The heart doesn’t have to work as hard in microgravity, leading to reduced conditioning and a smaller heart size. Upon return to Earth, a smaller, weaker heart can struggle.
Radiation Exposure: On Earth, we’re exposed to low levels of radiation, but in space astronauts face roughly 100 times more, equivalent to 150–6,000 chest X-rays.
How Astronauts Prepare for Space
Astronauts undergo extensive training to tackle the unique challenges of space travel. The process spans several years and includes multiple stages, each focusing on different aspects of spaceflight.
Basic Training: Candidates start with an intensive two-year foundational program at facilities like NASA’s Johnson Space Center.
Theoretical Lessons: Subjects such as mathematics, geology, meteorology, guidance and navigation, orbital dynamics, and physics provide a solid foundation for understanding space missions.
Physical Fitness: Candidates engage in cardiovascular, strength, and endurance training to achieve peak physical condition capable of handling microgravity demands.
Flight Training: Astronauts train in T-38 jets to develop rapid decision-making skills in high-performance environments. This also includes emergency procedures for scenarios like cabin depressurization or onboard fires.
Simulation Training: Simulations recreate experiences astronauts will face during and after flight while still on Earth.
Zero-Gravity Simulations: Parabolic flights provide microgravity experience, and tasks in the Neutral Buoyancy Laboratory allow astronauts to simulate spacewalks underwater.
Emergency Procedures: Trainees practice potential in-mission emergencies to ensure they can respond effectively under pressure.
Mission-Specific Training: Once assigned to a mission, astronauts undergo an additional 18 months of specialized training, which includes:
Equipment Familiarity: Learning to operate spacecraft systems and mission-specific gear.
Scientific Experiment Training: Preparing to conduct experiments and collect data in space.
Survival Training: Prepares astronauts for emergency landings on Earth and extreme conditions.
Psychological Preparation: Training to handle the mental challenges of long-duration missions.
Coping Strategies: Techniques for managing stress and maintaining psychological health during extended isolation.
Teamwork Skills: Practicing collaboration with crew members in confined environments, which is essential for mission success.
How Astronauts Live in Space
Astronauts start their day at 6 a.m. Greenwich Mean Time. On weekdays, they follow a carefully planned, highly structured routine coordinated with Mission Control. Their day typically begins with breakfast, personal hygiene, and tidying up, followed by a review of the day’s schedule. Blood samples are collected for analysis, and astronauts participate in a daily conference with Mission Control to ensure everyone is aligned on mission tasks. After checking the station’s air quality, they focus on conducting various scientific experiments. Physical fitness is also a priority, with crew members spending two hours on the treadmill or exercise bike daily.
After lunch, they take a short break before continuing with maintenance, research, and other experiments, performing another air quality check. The day ends with the crew completing final tasks, monitoring station systems, and attending a second daily planning conference to prepare for the next day, after which they have some free time.
Weekends are slightly more relaxed. Housekeeping and other station-related duties take priority, giving the crew time to catch up on maintenance and essential tasks.
What Do Astronauts Eat in Space?
On the space station, astronauts eat packaged foods such as soups like chicken stew and mushroom cream, casseroles like pasta with cheese or chicken with rice, appetizers like shrimp cocktail, and breakfast items like scrambled eggs and cereal.
NASA has developed a diverse menu for astronauts on the International Space Station (ISS), offering over 300 options of familiar comfort foods. Astronauts can also request personal favorites or “bonus foods” that remind them of home. Meals are typically packaged to prevent crumbs or liquids from floating away in microgravity.
How Do Astronauts Eat in Space?
Astronauts use a meal tray to hold their food containers. The tray can be strapped to the astronaut’s lap or attached to a wall. It acts as their dining plate, allowing them to choose from multiple foods at once, just like at home.
The food containers are single-use, and both containers and trays are cleaned with moist disinfectant wipes, eliminating the need for a dishwasher or kitchen sink. The galley is modular, equipped with a unit that heats and rehydrates food and beverages.
How Do Astronauts Use the Toilet in Space?
The toilet on the space station consists of a seat and a urine funnel. Astronauts use leg straps and thigh bars to secure themselves to the seat. The toilet works like a vacuum cleaner with fans that suck air and waste into the seat. Each astronaut has a personal urine funnel that must be attached to the hose adapter. The fans draw air and urine through the funnel and hose into the waste water tank; no flushing is needed.
How Do Astronauts Take a Shower?
Astronauts take sponge baths every day using two wipes—one for washing and one for rinsing—and use no-rinse shampoo to wash their hair. In zero gravity, water and soap stick to the skin, and any excess water is absorbed into the waste water tank.
How Do Astronauts Sleep in Space?
Each astronaut has a sleep mask and earplugs to block out noise and light. Sleeping in zero gravity can be tricky. Astronauts have to strap themselves in to avoid bumping into things while they sleep. The station and shuttle crew have sleeping bags that can be attached to a seat or a wall.
How Do Astronauts Communicate in Space?
Space, which is almost a perfect vacuum, doesn’t allow sound to travel or be heard by ears. Sound is the vibration of air particles, so any “sound” in space has to come from another source. That’s why astronauts use radio waves to communicate with each other during spacewalks.
When astronauts call home from the space station, they use a modified Softphone system through a laptop that routes signals via Internet Protocol (IP). They dial numbers using the computer keypad and speak through a headset, but there is usually about a one-second delay. The system is specially adapted to handle this delay, and if the station signal is blocked or out of satellite range, connection issues can occur. A device called the Orbital Communications Adapter enables high-speed data transfer, allowing astronauts to send emails and make video calls. They also use HAM radio, which has been part of space missions since 1983, for communication including emergencies.
How to Become an Astronaut?
Astronaut requirements have evolved along with NASA’s goals and missions. Today, to answer the question of how to become an astronaut, applicants are expected to meet the following qualifications:
Be a U.S. citizen.
Hold a master’s degree from an accredited institution in engineering, biological sciences, physical sciences, computer science, or mathematics.
Have at least three years of relevant professional experience after completing the degree (for medical doctors, residency can count as experience).
For pilots, have at least 1,000 hours as a Command Pilot, including a minimum of 850 hours in high-performance jet aircraft.
Successfully complete NASA’s long-duration flight astronaut physical.
The master’s degree requirement can be fulfilled through:
Two years of study toward a doctoral program in a relevant science, technology, engineering, or mathematics field.
Completion of a Doctor of Medicine, Osteopathic Medicine, or other relevant medical degree.
Completion of a nationally recognized test pilot school program.
Astronaut Ranks
Like other careers, astronauts also have distinct ranks and levels:
Space Agency | Title | Details |
NASA | Astronaut Candidate | Entry rank for individuals continuing astronaut training. |
Astronaut | Rank earned after completing training; Astronaut Badge (silver for training, gold for flight). | |
Roscosmos | Test Cosmonaut | Undergoes intensive training; can serve as a commander or flight engineer. |
Research Cosmonaut | Focuses on scientific research with a less intensive training program. | |
Pilot Cosmonaut | Responsible for piloting the spacecraft. | |
Trainer | Experienced cosmonauts who train new candidates. | |
CNSA | Astronaut Candidate | Similar to NASA; rank for individuals in training. |
Space Craft Pilot | Responsible for piloting the spacecraft. | |
Flight Engineer | Assists with mission operations and safety. | |
Mission Specialist | Conducts specific scientific experiments during missions; typically a non-career astronaut. | |
Genel Pozisyonlar | Commander | Responsible for mission success and crew safety. |
Pilot | Works closely with the commander to operate the spacecraft. | |
Mission Specialist | Performs specific tasks related to science or engineering. |
Astronaut Suit and Details
Now let's look at the features of the suit these heroes wear and how it protects them in space.
Characteristics of Astronaut Clothes
Feature | Details |
Protection | Space suits protect against vacuum, extreme temperatures, radiation, and micrometeoroids. |
Types of Suits | Three main types: IVA (intravehicular activity), EVA (extravehicular activity), and IEVA (intra/extravehicular activity). |
Life Support Systems | Includes a backpack equipped with life support systems containing an oxygen supply and environmental controls. |
Mobility | Designed for flexibility and mobility; newer suits feature improved joint designs for better movement. |
Cooling Systems | Includes cooling garments equipped with water tubes to regulate body temperature during spacewalks. |
Helmet Design | Helmets function like pressure bubbles and are made of strong materials to maintain the integrity of the suit. |
Material Layers | Suits consist of at least seven layers to provide insulation, protection, and functionality. |
Communication Equipment | They include integrated communication systems that allow astronauts to communicate with mission control and with each other. |
Customization | They are custom-designed to fit different body sizes and shapes, providing comfort and efficiency. |
Durability | They are built to withstand the harsh conditions of space and are also resistant to dust on planetary surfaces like the Moon and Mars. |
What Is an Astronaut Suit Made Of?
Component | Material | Function |
Inner Bladder | Polyurethane-coated nylon | Holds oxygen for breathing and maintains airtight integrity. |
Restraint Layer | Polyester fabric | Holds the Bladder in place and shapes it according to the astronaut’s body. |
Ripstop Layer | Tear-resistant fabric (usually nylon) | Provides structural integrity and protects against tears. |
Insulation Layers | Mylar (polyester film) | Retains body heat and provides insulation against extreme temperatures. |
Outer Layer | Combination of Teflon, Nomex, and Kevlar | Reflects sunlight, provides waterproofing, fire resistance, and puncture resistance. |
Cooling Garment | Water tubes woven with flexible spandex | Regulates body temperature and allow cooled water to circulate close to the skin. |
Hard Upper Torso | Fiberglass | Provides support and connects the suit to life support systems. |
Gloves | Neoprene and other materials | Provides mobility while handling objects and also offer thermal insulation and protection. |
Helmet | Strong plastic with gold-coated visor | Maintains pressure, provides visibility, and protects against solar radiation. |
Life Support System | Various materials including aluminum | Houses the oxygen supply, regulates pressure, circulates air, and removes carbon dioxide. |
How Much Does an Astronaut Suit Cost?
In 1974, NASA reported that a space suit cost between $15–22 million, which today is roughly equivalent to $83–122 million.
How Much Does an Astronaut Suit Weigh?
The Apollo suit, including the life support backpack, weighs around 81 kg. The Advanced Crew Escape Suit, including its life support system, weighs about 140 kg, with the suit itself weighing around 49 kg. However, once in space, the effective weight decreases due to reduced gravity. On the Moon, where gravity is lower, an astronaut suit weighs approximately 14 kg.
Astronauts Lost in Space
So far, no astronaut has ever failed to return from space. However, the first astronaut to venture away from the safety of their spacecraft without a tether was Bruce McCandless on February 7, 1984, reaching 100 meters from the Challenger space shuttle.
What Happens to Astronauts Who Die in Space?
Today, death in space is handled as follows: if someone dies on a mission in low Earth orbit, like on the International Space Station, the crew can return the body to Earth in a capsule within a few hours. If this happens on the Moon, the crew could bring the body back home within just a few days.
However, if an astronaut dies during a journey to Mars, the situation would be different. In this scenario, the crew likely wouldn’t be able to return immediately. Instead, the body would probably be brought back to Earth at the end of the mission, several years later. In the meantime, the crew would likely store the body in a separate compartment or in a special body bag. The controlled temperature and humidity inside the spacecraft would theoretically help preserve the body.
But what happens if someone goes into space without the protection of a spacesuit? I cover that in my blog: What Is Space, and What Is It Really Like? (More Than You Think!)
Notable Astronauts in History
Name | Achievement | Importance |
Yuri Gagarin | The first human to travel into space (Vostok 1, 1961) | Marked the beginning of manned space exploration. |
Alan Shepard | The first American to travel into space (Mercury-Redstone 3, 1961) | Paved the way for the U.S. space program. |
Valentina Tereşkova | The first woman to travel into space (Vostok 6, 1963) | Proved women’s capabilities in space exploration. |
John Glenn | The first American to orbit the Earth (Friendship 7, 1962) | Demonstrated the U.S.'s orbital capabilities. |
Aleksey Leonov | The first person to walk in space (Voskhod 2, 1965) | Paved the way for the space walking. |
Neil Armstrong | The first person to set foot on the Moon (Apollo 11, 1969) | Enabled humanity to set foot on another celestial body. |
Buzz Aldrin | The second person to set foot on the Moon (Apollo 11, 1969) | He joined Armstrong in the Apollo 11 mission. |
Sally Ride | The first American woman to travel into space (STS-7, 1983) | Reinforced the role of women in space exploration in the U.S. |
Chris Hadfield | The first person to play guitar in space (ISS, 2013) | Brought space life closer to popular culture. |
Peggy Whitson | The American astronaut who spent the longest time in space (665 days) | Set records for women and achieved many firsts at NASA. |
Gherman Titov | The youngest person to travel into space (25 years old - Vostok 2, 1961) | The second human in space and the youngest astronaut. |
Valery Polyakov | The human who spent the longest time in space on a single flight. (437 gün, Mir, 1994-1995) | It demonstrated human resilience in long-duration space missions. |
