How does spending prolonged time in microgravity affect the bodies of astronauts?
492003
Lack of pressure on mucles and spines can cause them (the muscles and spines not the astronauts) to deteriorate. Astronauts strap themselves to bike machines and excerize for hours daily when in space to maintain at the same health they'd be if they were on Earth not excercizing at all. If they fail to keep their muscles and bones active, they can experience painful damage to the muscles and even early signs of osteoperosis, the deterioration of bone mass that people on earth experience when they don't have enough calcuim, which can lead to injuring the bone. However, the excercise is easily enough done that maintaining gravity inside spacecraft is not an issue.
56936
OK... let's get graphic.\nFirst off..... you'd die! No way around that!\nWhat would kill you first is the question.\nSpace is incredibly cold, so instant exposure to space would freeze almost all liquid in your body solid.\nSpace is also a HUGE vaccum, so all the air would be sucked out of you either while you're freezing solid, of during your freezing process.... either way, you'd suffocate if you didn't freeze by some miracle.\nSpace has absolutely no compromising pressure like the inside of our atmospere. Our bodies are used to a certain atmosperic pressure. Without it (I.E in space) if you didn't freeze or suffocate, eventually the lack of pressure would collapse our fragile bodies.\nThe possibilities for death are indeed endless.
524184
The effect of weightlessness is due to the fact that the astronaut is falling towards the Earth at the same rate the spacecraft is falling.  I use the term "falling" because the spacecraft, and astronaut are both being accelerated towards the earth.  The reason they remain in orbit is because they have momentum perpendicular to the Earth.  So, like a weight tied to a rope being swung in a circle, the weight is constantly being pulled towards the center of the circle, but never actually moves to the center.  Likewise, the astronaut is pulled towards the Earth, but does not fall into the earth.
1050720
Our muscles, liek any oteh rtissue constantly need oxygen. while teh heart pumps teh blood to teh muscle tissues via arteries, teh motion of teh muscle temsleves when they flex helps propel the blood through teh veins back to teh heart. When we sit for long hoursm our back muscles barely move, therefore they do get poor circulation, which starves them of oxygen, resulting in acumulation of toxic lactic acid which causes cramping and knotting of back muscles. Stress doesnt hlep , because it causes a diminished blood flow to muscles and increased flow to internal organs as teh body tries to protect itself from iminant danger.\nA massage forces fresh oxygen rich blood into teh muscle, allowing teh muscle to relax. This sends a feel good signal to teh brain. Also skin to skin contact releases a hormone called oxytocin that promotes a relaxed and eup[horic state
250765
minor variations in atmospheric pressure can cause some physical effects in people who are sensitive to the changes.  my own ears tend to pop whenever there's a high or low pressure system moving in.  i'm sure everyone has an aunt who can predict weather when her bones start aching.  these changes are caused primarily by fluctuations in atmospheric pressure.\n\nas atmospheric pressure drops (such as in increasing altitude in a plane or mountain climbing), breathing becomes more difficult (there's less oxygen because the air is thinner), and temperature usually drops (thinner air can't hold as much heat, and is also easier to move in high winds so it whips past much quicker).  eventually the pressure can drop so much that it becomes a vacuum (complete lack of atmosphere, or zero air pressure).  in a vacuum, there would of course be no oxygen.  blood vessels (especially thin walled ones in the face and nose) may burst - creating nose bleeds and gin blossoms.  and as atmospheric pressure decreases, the boiling point of liquids decreases.  in a total vacuum, any liquids would boil away immediately into vapour.  this includes any moisture in the human body.  it wouldn't happen instantly, but i can't imagine that it would be terribly fun to experience.  fairly soon you'd end with a freeze-dried corpse, weighing only a few pounds as all the water disappeared from the body.  hundreds of bad science fiction films to the contrary, a human body would not explode if exposed to vacuum.\n\nthe effects of high pressure would not be quite as dramatic.  higher and higher pressure would make breathing increasingly difficult as the air becomes 'thicker' and harder to move.  we would feel increase most noticeably in our ears and temples, as the pressure on our body starts to squeeze us.  it would be very much like diving to the bottom of the swimming pool, except we wouldn't drown.\n\non Earth, there's nowhere that the atmosphere would produce that much pressure except inside an artificial pressure container like a hyperbaric chamber.  on other planets, there might be much different atmospheric pressures.  the atmosphere on Venus is over 400 times denser than the Earth's.  this would be enough to squash us like we'd been run over by a steamroller even if the atmosphere wasn't poisonous and full of sulphuric acid.
986287
Walking, or any other form of non-airborne locomotion - you'd have to swim through the air\n\nCooking would be a bit complicated, everything would have to be contained. And forget a bowl of cereal.  Solid food would have to be in chunks, liquids in a pouch.\n\nCleaning up afterwards would be tough - how do you keep the hot soapy water in the sink?\n\nThink of all the things that would have to be restained from floating around as you go about your daily business.\n\nSleeping might be a bit more comfortable though, as long as you're tethered so you don't bump into walls all night long.\n\nAll in all, it would be similiar to life aboard a non-rotating space station.
818887
Will be a while before that body falls by gravity
455306
Oxygen, like a lot of substances our body needs, can be harmful in large quantities.  This is partly due to its highly electromagnetic and hydrophyllic nature.  As any patient that has been on oxygen therapy can tell you, your body is "set" to use a certain percentage of oxygen in the air we breathe.  If we get used to a higher amount, and then this amount is depreived, we feel light-headed and weak.  This is because at higher levels of oxygen, our lungs become accustomed to a smaller amount of effort to extract and use the oxygen from the air.  \n\nOxygen's corrosive nature is not found in the O2 form however, but the O and O3 (ozone) forms.  This is because oxygen is most stable in the O2 form.  This is where oxygen "wants" to be.  The O3 and O forms are unstable, and prone to reactions.    \n\n"Oxygen can be toxic at elevated partial pressures (i.e. high relative concentrations). This is important in some forms of scuba diving, such as with a rebreather.\n\nCertain derivatives of oxygen, such as ozone (O3), singlet oxygen, hydrogen peroxide, hydroxyl radicals and superoxide, are also highly toxic. The body has developed mechanisms to protect against these toxic compounds. For instance, the naturally-occurring glutathione can act as an antioxidant, as can bilirubin which is normally a breakdown product of hemoglobin. To protect against the destructive nature of peroxides, nearly every organism on earth has developed some form of the enzyme catalase, which very quickly disproportionates peroxide into water and dioxygen.\n\nHighly concentrated sources of oxygen promote rapid combustion and therefore are fire and explosion hazards in the presence of fuels. The fire that killed the Apollo 1 crew on a test launchpad spread so rapidly because the capsule was pressurized with pure oxygen as would be usual in an actual flight, but to maintain positive pressure in the capsule, this was at slightly more than atmospheric pressure instead of the 1/3 pressure that would be used in flight. (See partial pressure.) Similar hazards also apply to compounds of oxygen with a high oxidative potential, such as chlorates, perchlorates, and dichromates; they also can often cause chemical burns.\n\nOxygen derivatives are prone to form free radicals, especially in metabolic processes. Because they can cause severe damage to cells and their DNA, they form part of theories of carcinogenesis and aging." (Wikipedia 2006)\n\n"Oxygen is the most abundant element on this planet. The earth's crust is 46.6% oxygen by weight, the oceans are 86% oxygen by weight, and the atmosphere is 21% oxygen by volume. The name oxygen comes from the Greek stems oxys, "acid," and gennan, "to form or generate." Thus, oxygen literally means "acid former." This name was introduced by Lavoisier, who noticed that compounds rich in oxygen, such as SO2 and P4O10, dissolve in water to give acids.\n\n"Fluorine is the only element that is more electronegative than oxygen. As a result, oxygen gains electrons in virtually all its chemical reactions. Each O2 molecule must gain four electrons to satisfy the octets of the two oxygen atoms." ("Chemistry of Oxygen" - Bodner Research Group)
965765
It differs a bit as those who live at high altitudes have built up a tolerance.  It also depends on how long you will be above a certain altitude.  However, prolongned exposure above 17,000 feet can result in hypoxia which causes fluid build up so that the person actually drowns from the fluid accumulation in their lungs.
1178549
Well, the second half of your question is easier to answer -- these problems haven't been solved yet, and they are of great concern to the folks at NASA and the ESA (yes, I know there are other nations and organizations working on space travel, but most of them are still working on getting into orbit for more than a few hours)  If you're talking about simply travelling to the moon or Mars and setting up a colony (one-way trip, in other words), then the G-forces you're worried about are only really experienced during launch, and to a lesser extent during the burn to slow down for re-entry.  Really, the problems that keep mission control specialists up at night are bone density loss from lack of resistance in microgravity (the latest data show that each month spent in near zero-G lowers bone density by 10%, meaning you'll be quasi-osteoporotic by the time you get to Mars and back), constant radiation exposure from the sun and cosmic radiation (not to mention if you get caught in a solar flare), and the usual food, water and air issues that you get on any extended voyage.  Oh yeah, and vitamins tend to break down faster in an oxygenated, low-gravity environment, so any supplements brought along to fight bone loss as well as many medications to treat illness along the way simply won't work after a couple of weeks.  Big issues, no clear answers just yet.
911012
In all probability the child body would adapt to the weightless environment fine as the human body tends to adapt well, and is quite resilient. If, however, the child was to land back on earth, the child's body may experience physical trauma, as Astronauts who have experienced extended space flight have had to be rehabilitated when they return to earth. This is because their blood flow, and muscle mass changes to adapt to a weightless environment, and so it also has to adapt back to an environment with gravity.
7157
The suits protect astronauts from UV radiation (their visors and suits), but they do NOT protect them from the radiation you are refering to.\n\nAstronauts are exposed to radiation.  NASA does everything it can to minimize that exposure.  They limit the time spent outside the spacecraft.  They carefully monitor the Sun for radiation bursts.  They also track and measure the radiation trapped in the radiation belts (which is the biggest threat to the astronauts), and they time space walks to minimize that exposure.\n\nA space walk is a big risk for an astronaut.  Besides radiation, meteoroids are a threat as well.  It is quite a feat of bravery to make a space walk.
262346
Well, the youngest astronauts would be in their late 20's, and they should be sexually mature enough to be the masters of their domains for the duration of their flights. Most astronauts shouldn't be in space for more than a few weeks at a time, anyway.
1100560
Antigravity on earth at least = negative G’s.  you can achieve this by jumping a dirt bike or even your car (not recommended).  \n\nThere is even a flight called the Vomit Comet.  NASA operates a KC-135 craft outfitted to perform parabolic arcs that give weightlessness or more properly freefall lasting 20-25 seconds. The plane is nicknamed "The Vomit Comet" because of the large number of researchers that become ill. Imagine a roller coaster thousands of feet high. Imagine going up and down that roller coaster repeatedly for a coupole of hours. Now you know why so many people get sick!
847307
yes, your body is working against gravity sitting up and working with it laying down. however, your body should adjust to the sitting position after awhile thanks to the autonomic nervous system.
719839
in the shuttle? absorbed and filtered. Their is still humidity but under control.\n\nIn the outer space there isn't any  just on rocks(asteroid)
956593
A major problem with air travel and blood vessels is sitting down and not moving the lower extremeties. Blood tends to coagulate and create thrombosis which can travel throughout the body. The thrombosis can end up in blood vessels in the brain and block arteries.