Astronauts exercise six days a week for about 2.5 hours a day while in microgravity to limit the loss of muscle mass and bone density.

Astronauts maintain bone, muscle, and cardiovascular health with physical activity. It's crucial that they make time to exercise for approximately two hours per day. This resource offers a behind-the-scenes look at how high-intensity workouts help prevent muscle atrophy, bone density loss, and aerobic decline during monthslong space missions.

All that exercising, and astronauts still are likely to lose a large amount of muscle mass while in microgravity. Astronauts can lose up to 20 percent of their muscle in as little as five days in space. Currently, tracking muscle loss means waiting until astronauts land to remeasure their muscle density post-trip. This article explains a NASA-backed fitness wearable that may be able to track muscle atrophy as it happens.

Microgravity is known to cause arterial hardening, bone weakening, and other health issues, but the novelty of space tourism and the minimal exposure time for suborbital trips have limited the number of research studies. Many companies have participants sign extensive waivers to bypass the requirement of specific medical standards.

Astronauts can lose 20% of their muscle mass after two weeks and 10% of their bone mass after six months in space. Decreased sharpness of eyesight and changes in neural connectivity, brain structure and gut bacteria have also been observed.

Experiments conducted on the International Space Station have shown that microgravity environments can delay viral and bacterial infections and induce mutations not seen on Earth. These mutations could have implications for long-term space missions and human health and suggest space can serve as a testing ground for developing new therapeutic approaches.

Microgravity makes personal care more complex on the International Space Station, where stray, floating materials must be captured to prevent them from entering vents and clogging filtration vents. No-rinse shampoo, water pouches, and other strategies help minimize obstructions.

Experiencing 15 sunrises and sunsets a day while aboard the International Space Station, visitors preserve their circadian rhythms and mental health with fixed timetables. Astronauts have described sleep as living in a vacuum cleaner due to ongoing air filtration.

From "synchronized space swimming" to "weightless sharpshooting," crew members in 2021 competed in microgravity versions of events from the summer Games. The "lack-of-floor routine" featured mid-air gymnastics as astronauts floated through space station modules.

Astronauts primarily consume freeze-dried meals, which are rehydrated with water recycled from urine and perspiration, directly from bags. Condiments and select cultural items from crew members can enhance the meal experience by boosting flavor. Many individuals report experiencing "food fatigue" due to a lack of fresh produce, limited menu variety, and lingering scents.

You’re stranded hundreds of miles away from your friends and family, constantly surrounded by coworkers who also are your roommates, and you’re only allowed the shortest of walks outside. There’s also no takeout, and gravity has essentially broken up with you. You might need a little help adjusting mentally. That’s where space psychologists and psychiatrists step in, according to this article.

The International Space Station's sterile conditions deprive astronauts of the opportunity to strengthen their immune systems through microbial exposure. To address this problem, future missions may use probiotic-based cleaners and foster diverse microbes in space habitats.

Researchers are developing pharmaceutical solutions for astronauts, whose bodies may not respond the same way in space as they would on Earth. Similar to how microgravity causes changes to astronaut physiology, the environmental shift enables new...

Outside the protective atmosphere of Earth, astronauts are constantly bombarded by radiation, which, among other dangers, increases the risk cancer. While those of us on Earth can mitigate the effects of similar radiation by limiting exposure,...

This playlist features clips of astronauts aboard the International Space Station explaining how they cook, eat, sleep, and conduct research in microgravity. Other activities to pass the time, including watering plants and playing soccer, are also shown.

Due to Earth's gravity, liquids and solids sink in our digestive system, while gases rise, allowing them to be forced back up the esophagus to be expelled through burping. In the microgravity environment of the International Space Station, burping would result in vomiting if it were possible.

About 93% of water used onboard the International Space Station is recycled through filtration and purification systems that have since been used in regions lacking access to clean water. Treatments to mitigate bone loss and muscle atrophy in astronauts can also help aging adults.

A 2007 mission launched several species into low-Earth orbit, exposing them to microgravity in temperature-controlled modules. Survivability rates were high for microgravity exposure alone, but plummeted when combined with exposure to the full UV spectrum and the vacuum of space.

A collection of 44 studies—primarily based on data from a 2021 tourist trip to low Earth orbit—identified immune system disruption and some kidney damage in tourists, with women appearing to recover from space travel faster than men. Return trips from Mars may require human travelers to be on dialysis.

Astronauts aboard the International Space Station experience 16 daily sunrises, but scientists have learned to try to promote circadian rhythms by phasing through several light settings aboard the ISS to improve astronauts’ sleep and productivity.

Gravity can cause gaps, such as those in the chambers of a 3D-printed heart, to collapse before stem cells, hydrogels, and biochemicals bind together during the bioprinting process. Rather than Earth's surface, some bioprinting is done on the International Space Station, where defective organs are also printed to test treatment methods.

From space radiation to isolation, humans struggle when it comes to traveling and living in space. What does this mean for long-term spaceflight? This hour-long podcast episode attempts to answer that question while detailing five major spaceflight hazards.

Between 60% and 90% of astronauts get motion sick in space—and many also get motion sick during the first few days upon return. Motion sickness on Earth does not seem to correlate with whether or not astronauts get motion sick in space, so it's not possible to predict who will get ill.

In the mid-20th century, 11 deaf men volunteered for a series of experiments that offered unprecedented insights into the effects of weightlessness on the human body. Most of the men had become deaf in early childhood as a result of spinal meningitis, a condition known to damage the vestibular system and make them less susceptible to motion sickness. For a decade, these men participated in extreme motion sickness situations, including living in a slowly spinning room, spending time in centrifuge pods designed to simulate hypergravity, and flying in parabolic flights sometimes referred to as the "Vomit Comet."

Just because you’re living at the International Space Station doesn’t mean your cravings disappear. In this video, Chef Traci Des Jardins explains the best way to make a burrito while experiencing microgravity.

By traveling near a moving celestial object, a passing object can gain or lose speed and change direction due to the acceleration provided by their mutual gravity. Some missions are planned around spacecraft performing multiple assists, or slingshots, to reduce fuel requirements for long-distance travel.

NASA is using the Kraken, a 50-foot-long, 100-ton US Navy research device, to simulate space motion sickness and vertigo and test possible recovery strategies, including testing out different, specific head movements. The Kraken, located at Wright-Patterson Air Force Base near Dayton, Ohio, can rotate participants at exposures of up to 3G.

After John Glenn became the first American to demonstrate that eating in space was possible by eating apple puree out of a tube, meals were prepared for astronauts to meet an approximately 2,800-calorie-a-day requirement via freeze-dried foods. Meal quality gradually improved throughout the Apollo program, including the Apollo 8 crew's nondehydrated Christmas meal in 1968.

Analog missions in volcanic terrains and craters mimic Martian and lunar environments. Crew members operating in these missions, including at sites in Utah, Nevada, Arizona, and Hawai'i, test suits and specialized space instruments under simulated conditions.

An inactive Russian satellite broke up into nearly 200 pieces, prompting astronauts on the space station to take shelter in a docked spacecraft and a capsule that could be used to escape in case of emergency.

Mix motion sickness minus gravity with a host of other variables, and you’ve got a recipe for space adaptation syndrome. It can hit anyone, even astronauts who escaped the issue previously. This article details the history and science behind space sickness.

Different space agencies develop different modules of the ISS, meaning their controls, documentation, and instrumentation are not always written in English. Because the first modules were delivered using US and Russian spacecraft, astronauts have been historically trained in both languages.

NASA refused to take Dennis Tito, who had no formal training as an astronaut, up to the International Space Station. Instead, the American engineer and entrepreneur traveled aboard the Soyuz TM-32 mission and described the initial experience of microgravity after engine shut-off as the "most spectacular" part of the flight.

NASA's Extravehicular Mobility Unit has been in use since the 1980s, with 11 units of the model in existence and four in active use on the ISS at any given time. It consists of 11 layers, a primary life support system (which resembles a backpack), a drinking bag, and more.

There is only a certain amount of gravitational force that the body can handle before dealing with consequences like short-term vision loss or unconsciousness. Increased scientific understanding has largely reduced these impacts, with engineers combining periods of intense pressure with periods of relief.

Millions of fragments from satellites, rockets, and other spacecraft that are no longer operational move thousands of meters per second as they circle Earth. Even a piece of debris a centimeter in size can cause mission-ending damage to space stations, telescopes, and astronauts.

The retirement of the International Space Station in 2030 has led NASA to refocus its efforts on continuing microgravity research through private partnerships, including the support of multiple commercial space stations' design and development.