Learn just how dangerous space is. Then, consider the stresses on the human body during launch, principally the high g-forces that astronauts endure as their rocket accelerates toward space. Also, review pre-launch preparations, including a precautionary quarantine to avoid falling ill during a mission, the readjustment of the body’s biological clock, and a recommended bowel cleanse.
Once in orbit, space travelers must deal with weightlessness, which can induce temporary or long-lasting motion sickness, termed "space sickness." It's hard to predict who will be affected, since even experienced fighter pilots can fall violently ill. However, some other species such as tree frogs seem to have it all figured out. Analyze research on this problem, its apparent causes, and measures to combat it.
Humans didn't evolve to live in space. Not surprisingly, long missions can lead to an array of health issues. Learn how weightlessness affects every system in the body, leaving astronauts much weaker, anemic, myopic, osteoporotic, and prone to illness and back problems. Explore countermeasures that can keep them relatively healthy while in space and speed their recovery upon return to Earth.
Space may evoke a sterile environment, but in reality it promotes a zoo of microbes. Discover the challenges of staying clean in the International Space Station, where an astronaut's water ration for personal hygiene is 0.5 liters per day, and a change of clothes must last months. Restricted diet, microgravity, and other factors also affect the microbiome in ways that can have a negative impact on health.
A spacesuit is a miniature spaceship, in which an astronaut must live, work, eat, and excrete without the prospect of escape for many hours. Consider the challenges of scratching your nose or getting a snack without the ability to use your hands. Also, look at the perils both inside the suit and outside, including weightlessness, temperature extremes, radiation, and micrometeorites.
Hollywood portrays the vacuum of space as able to boil, explode, flash freeze, or otherwise violently end the life of an unprotected astronaut. In fact, exposure to a vacuum is less dramatic, although lethal unless prompt action is taken. Analyze the physics of a vacuum and how the body responds to the near-total lack of air. Study real-life cases, including an eerie survivor's report.
The lack of air in space causes extreme temperature differences—from broiling heat in full sun to bitter cold inches away in shadow. Weightlessness also means there are no convection currents to dissipate heat. Review some uncomfortable astronaut experiences with temperature and consider the engineering challenge of keeping the International Space Station reasonably pleasant for the crew.
Do you like fresh or crunchy food? If so, you're mostly out of luck in space, where meals must have a long shelf life and must have a mushy, crumble-proof texture to avoid particles floating in the cabin. Explore the culinary compromises of spaceflight, where food longevity and consistency are not the only issues with palatability, since taste and digestion are also markedly affected by the space environment.
Long-duration spaceflight can be a grueling test of astronaut morale—and even sanity. Probe some of the disagreements that inevitably arise when highly motivated people are confined for months at a time. Discover that one mission reportedly erupted in a fistfight. Also, consider the suitability of men versus women for the challenges of life in space and evaluate the advantages of a mixed-sex crew.
One of the riskiest aspects of spaceflight is radiation due to ejections from the Sun, charged particles trapped in Earth's magnetic field, and galactic cosmic rays produced by supernova explosions and other violent events. On Earth, we are mostly protected from this rain of ionizing particles that can lead to cancers and other disorders. Learn the limited measures astronauts can take.
Astronauts are typically super healthy, but they can still suffer medical emergencies in space, where it is extremely difficult to treat them. During the Apollo program, one Moon walker had a heart attack and had to wait days before he could see doctors back on Earth. Ponder the problem of performing even minor surgery in space, where weightlessness presents unique challenges.
A highlight of every space mission is landing—either on Earth or another planet. Potentially more dangerous than launch, this maneuver involves deceleration from great speed, using atmospheric friction, retrorockets, or both. Astronauts have been injured or died during this step. As with other perils of spaceflight, women have physiological advantages over men, showing that they truly have the right stuff.