Humans, since the dawn of time, have been interested in things outside of Earth. People were curious about what weightlessness would be like and what effects it would have on the human body. Valerie Neal, curator and chair of space history at the Smithsonian National Air and Space Museum, said, "All these normal things that we take for granted, no one really knew what was going to happen" (Smithsonian). At first, scientists sent simple organisms such as mice, dogs and monkeys into space. Now, scientists are able to send real, living people to the Moon and beyond through the study of space exploration. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essayAfter John Glenn became the first person to orbit the Earth and Neil Armstrong set foot on the Moon, a new insight into the effect of space on the Moon has emerged. the human body, and new inventions have appeared in space medicine. Space medicine is the development of technologies designed to keep astronauts alive and healthy in space and medical experiments performed in orbit to take advantage of the unique environment of space (Leslie). They realized that astronauts could lose bone mass, have heart and circulatory problems, and that brain function could decline. These are just some of the negative effects that space can have on the human body. The human skeletal system is the primary support system, storing key nutrients, producing blood and protecting many vital organs. In space, astronauts are likely to lose bone mass. This may not pose too much of a problem in space, but upon return to Earth the risk of fractures and breakage could be higher. When astronauts travel in space, the weight supported by their bones is significantly reduced. This weakens their bones and begins to deteriorate. There is a noticeable change when the calcium stored in the bones begins to be released into the bloodstream when the bones are not used as usual. This phenomenon is similar to osteoporosis, a disease that humans on Earth suffer from when they do not use their muscles and bones properly. The most undeniable change in bone mass occurs between two and five months in space. Some astronauts on the Mir spacecraft lost up to 20% of their bone mass (Dunbar). John Uri, mission scientist for the Shuttle-Mir cooperative program, discovered that the spine, legs and hips tend to lose more bone mass than any other part. (NBC, 1998) To date, we still do not know the exact cause of osteoporosis upon return from space. Fortunately, several scientists from the United States and Canada have elaborated and concluded that the best way to keep the majority of their bone mass intact is to do weight-bearing exercises such as walking, jogging, volleyball and basketball (Canadian Space Agency). These recreational activities can also increase the heart rate, keeping the heart pumping and keeping the blood pumping strongly. The heart and circulatory system are another important factor in keeping people alive and healthy in space. Staying in space for prolonged periods can cause heart problems upon return to Earth. In space, the heart physically changes shape. On Earth, the heart is more of an oblong oval, and in space it becomes,.