Space

Let’s learn about surviving a trip to Mars

Astronauts would face dangers both getting to and surviving on the Red Planet

an astronaut in the foreground kneels on the red terrain of Mars and looks at a rocket ship parked in the distance

A trip to Mars may be many years off. But scientists are already figuring out what it would take to keep people safe and healthy on a journey to the Red Planet.

peepo/E+/Getty Images

By Maria Temming

So far, Mars has been the domain of space robots. Over the last 60 years, many spacecraft have flown by, orbited and even landed on the Red Planet. But human explorers could work faster and be more flexible than machines. Not to mention, setting foot on Mars would be a major milestone in space exploration. That’s why the United States, China and other countries want to send people to Mars. But surviving this adventure would be no easy feat.

A Mars mission would be the farthest journey in human history. At an average 225 million kilometers (140 million miles) away, Mars would take at least six months for astronauts to reach. (It would take at least another six months to get back home). In contrast, Apollo astronauts got to the moon in few days.

While space travel is never free of danger, the length of a roundtrip to Mars poses many extra health risks. For one thing, floating in microgravity for long periods weakens bones and muscles. Plus, it allows fluid to build up in the head, putting pressure behind the eyes and causing vision problems. Artificial gravity machines could help.

But then there’s space radiation to worry about. The Earth’s magnetic field protects astronauts near Earth from high-energy cosmic rays. Those charged particles might raise the risk of cancer and other health problems. On longer journeys, though, astronauts would be exposed for months. Taking certain vitamins could reduce the impacts. But scientists are still working out the details.

Mars explorers will have to pack light to lift off from Earth. But they won’t be able to restock on supplies like astronauts on the space station do. Astronauts on the space station practice for this by growing lettuce and other food in space. Engineers are also developing 3-D printing techniques that could let future Mars astronauts build tools as needed. The material for those tools could come from the astronauts themselves. For instance, astronaut pee could feed yeast that churns out ingredients to make plastic.

Setting up and surviving at a Mars colony would be even more complicated. Since astronauts can’t haul construction materials from Earth, scientists are dreaming up ways for astronauts to use materials on Mars. Long-term visitors would also need plenty of oxygen to breathe. A device on NASA’s Perseverance rover is currently laying the groundwork for a future Mars oxygen factory. The device pries oxygen off molecules of carbon dioxide, the main gas in Mars’ atmosphere.

Planning for a trip to Mars isn’t just about protecting astronauts. It’s also about protecting Mars from astronauts. Humans are teeming with microbes. And spreading those microbes could compromise the search for life on Mars. As a result, a key part of responsible space exploration is making sure Earth germs don’t infect other planets.

Want to know more? We’ve got some stories to get you started:

Preparing for that trip to Mars Space farming techniques, next-generation rockets and 3-D printing could all factor into a successful trip to Mars. (2/22/2018) Readability: 6.6

Surviving Mars missions will take planning and lots of innovation En route to Mars, astronauts will face health risks from microgravity, radiation and more. (10/22/2020) Readability: 8.0

How a year in space affected Scott Kelly’s health A comparison to his twin looks at how long-term spaceflight changes the human body. (5/17/2019) Readability: 7.3

Innovations to help astronauts survive on Mars could also be used to overcome challenges on Earth.

Explore more

Scientists Say: Microgravity

Explainer: Gravity and microgravity

Let’s learn about Mars

Let’s learn about gravity

The ultimate getaway — visiting the Red Planet

Analyze This: Insect shells could help builders on Mars

En route to Mars, astronauts may face big health risks

The Perseverance rover split CO2 on Mars to make breathable air

What to wear on Mars

Want a tougher space suit? Just add liquid

Here’s how a new sleeping bag could protect astronauts’ eyesight

Space travel may harm health by damaging cells’ powerhouses

Staying grounded in space requires artificial gravity

Human waste could power plastic-making in space

Keeping space missions from infecting Earth and other worlds

Activities

Word find

Design your own sustainable Mars colony with guidance from NASA. Take inspiration from communities on Earth and learn about the limitations of the Martian environment to build a model of your ideal human base on the Red Planet. Or, follow NASA’s instructions to build your own model Mars’ rover.  

Power Words

More About Power Words

3-D printing: A means of producing physical items — including toys, foods and even body parts — using a machine that takes instructions from a computer program. That program tells the machine how and where to lay down successive layers of some raw material (the “ink”) to create a three-dimensional object.

astronaut: Someone trained to travel into space for research and exploration.

atmosphere: The envelope of gases surrounding Earth, another planet or a moon.

cancer: Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.

carbon dioxide: (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter burns (including fossil fuels like oil or gas). Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

cosmic rays: Very high-energy particles, mostly protons, that bombard Earth from all directions. These particles originate outside our solar system. They are equivalent to the nucleus of an atom. They travel through space at high rates of speed (often close to the speed of light).

engineer: A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need. (v.) To perform these tasks, or the name for a person who performs such tasks.

germ: Any one-celled microorganism, such as a bacterium or fungal species, or a virus particle. Some germs cause disease. Others can promote the health of more complex organisms, including birds and mammals. The health effects of most germs, however, remain unknown.

gravity: The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its gravity.

infect: To spread a disease from one organism to another. This usually involves introducing some sort of disease-causing germ to an individual.

insect: A type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.

International Space Station: An artificial satellite that orbits Earth. Run by the United States and Russia, this station provides a research laboratory from which scientists can conduct experiments in biology, physics and astronomy — and make observations of Earth.

Mars: The fourth planet from the sun, just one planet out from Earth. Like Earth, it has seasons and moisture. But its diameter is only about half as big as Earth’s.

microbe: Short for microorganism. A living thing that is too small to see with the unaided eye, including bacteria, some fungi and many other organisms such as amoebas. Most consist of a single cell.

microgravity: Gravity that is a fraction of the force experienced at sea level on Earth.

milestone: An important step on the road to stated goal or achievement. The term gets its name from the stone markers that communities used to erect along the side of the road to inform travelers how far they still had to go (in miles) before reaching a town.

molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

moon: The natural satellite of any planet.

muscle: A type of tissue used to produce movement by contracting its cells, known as muscle fibers. Muscle is rich in protein, which is why predatory species seek prey containing lots of this tissue.

oxygen: A gas that makes up about 21 percent of Earth's atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).

particle: A minute amount of something.

planet: A large celestial object that orbits a star but unlike a star does not generate any visible light.

plastic: Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation. (adj.) A material that is able to adapt by changing shape or possibly even changing its function.

pressure: Force applied uniformly over a surface, measured as force per unit of area.

radiation: (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.

Red Planet: A nickname for Mars.

robot: A machine that can sense its environment, process information and respond with specific actions. Some robots can act without any human input, while others are guided by a human.

rocket: Something propelled into the air or through space, sometimes as a weapon of war. A rocket usually is lofted by the release of exhaust gases as some fuel burns. (v.) Something that flings into space at high speed as if fueled by combustion.

shell: The normally hard, protective outer covering of something. It could cover a mollusk or crustacean (such as a mussel or crab), a bird’s egg or some other relatively soft tissue that needs protection (such as a tree nut or peanut).

supplement: (verb) To add to something. (in nutrition) Something taken in pill or liquid form — often a vitamin or mineral — to improve the diet. For instance, it may provide more of some nutrient that is believed to benefit health. It may also provide some substance to the diet that is claimed to promote health.

tool: An object that a person or other animal makes or obtains and then uses to carry out some purpose such as reaching food, defending itself or grooming.

vitamin: Any of a group of chemicals that are essential for normal growth and nutrition and are required in small quantities in the diet because either they cannot be made by the body or the body cannot easily make them in sufficient amounts to support health.

yeast: One-celled fungi that can ferment carbohydrates (like sugars), producing carbon dioxide and alcohol. They also play a pivotal role in making many baked products rise.

About Maria Temming

Maria Temming is the Assistant Managing Editor at Science News Explores. She has bachelor's degrees in physics and English, and a master's in science writing.

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