Summary: The Effects Of Long-Term Space Flight

Isaiah Peterson

ESS 101

Erika Harnett

23 October 2015

Research Paper Rough Draft The main challenge the characters of my story grapple with is the effects of long-term space flight on the human body. As a species that evolved terrestrially, human bodies are naturally ill-suited for the zero-gravity environment of outer space. The lack of a constant gravitational force can do serious harm to a person, including weakening bones to the point that they break easily, diminishing muscle fiber strength, and overall making the transition back to life in an environment with gravity much more difficult. Feedback collected from astronauts in the Apollo missions and current astronauts living in the International Space Station provide examples of the strict

Human muscles acclimate to the constant pull of gravity, or in the case of astronauts, the lack thereof. With time, an astronaut's muscles grow accustomed to a minimally required amount of strength necessary to adapt to a zero-gravity environment. In fact, the effects of prolonged exposure to weightlessness achieves the same effect as adding about 30 years to a person’s life in terms of its negative impact on physical strength [1]. To give a more detailed answer, NASA Flight Surgeon Jeff Jones estimates that muscle strength atrophies by about 30-40% [2] when in low-gravity situations. In extreme situations, NASA estimates that muscle mass can deteriorate at a rate of 5% per week [3]. All muscles of the body fall prey to this effect, even the heart. With less force required to circulate blood throughout the body, the heart too slowly decreases in size

In similar fashion to muscles, bones will atrophy if not presented with the ever-present pull of gravity. NASA predictions indicate that bone integrity could emaciate up to 40-60% while exposed to the lack of gravity in space [3]. This type of bone loss experienced by astronauts is a form of osteoporosis, a bone ailment usually suffered by the elderly on Earth. Although the process of bone density reduction occurs throughout an astronaut's time in space, the second and fifth months in space prove the most acute [5]. Alongside the reduction of bone density and strength comes the obvious risk of breaking bones much more easily while in space [5]. If an essential crew member suffers a broken bone in space while on the job, the astronaut’s mission could be put in jeopardy. In addition, as the body deconstructs now unnecessary areas of an astronaut's bones, the calcium byproducts are recycled into the body. An overabundance of calcium can then lead to kidney stones creation, exacerbating an already unpleasant situation for astronauts