The Science Journal of the Lander College of Arts and Sciences Volume 8 Number 1 Fall 2014 - 1-1-2014 How Does Spaceflight Affect the Human Body? Sara Dina Feinzeig Touro College Follow this and additional works at: https://touroscholar.touro.edu/sjlcas Part of the Biology Commons Recommended Citation Feinzeig, S. D. (2014). How Does Spaceflight Affect the Human Body?. The Science Journal of the Lander College of Arts and Sciences, 8(1). Retrieved from https://touroscholar.touro.edu/sjlcas/vol8/iss1/5 This Article is brought to you for free and open access by the Lander College of Arts and Sciences at Touro Scholar. It has been accepted for inclusion in The Science Journal of the Lander College of Arts and Sciences by an authorized editor of Touro Scholar. For more information, please contact [email protected]. How Does Spaceflight Affect the Human Body? By: Sara Dina Feinzeig Sara graduated in June 2014 with a B.S. in biology. Sara has been accepted into the Touro Winthrop Physician Assistant Program. Abstract Spaceflight can impact just about every organ of the human body. The launch into space increases gravitational forces, which may decrease consciousness. Once subjected to the microgravity of outer space, the constant mechanical stress exerted on the body from Earth’s gravity decreases enormously, causing bone degeneration to occur. Calcium, a major component of bone is excreted in very high amounts, often leading to the formation of calcium kidney stones. Astronauts perform weight bearing exercise, take osteoporosis drugs and calcium and vitamin D supplements in order to combat bone loss. The vertebrae of the spine are also impacted by the lack of gravity. The spine actually expands up to two inches. On Earth, gravity pulls all the liquid of the body to the lower extremities. Without gravity, the liquids are equally dispersed throughout the body causing faces to appear puffy and increasing pressure on the brain due to excessive cerebrospinal fluid. The body responds to this liquid buildup by eliminating plasma and red blood cells, causing anemia. The increased fluids flatten astronaut’s eyeballs, and they often experience farsightedness. The immune system is also impacted during spaceflight as T-cells are not activated properly. Astronauts are also im- pacted by an excess radiation, which can increase the chances of future occurrences of cancer or cataracts. Muscle atrophy takes place as a result of microgravity as well as other factors. Exercise along with growth hormone, are recommended in order to combat the muscle degeneration. In space, the vestibular system of the ear does not function properly and impairs proper balance which can result in space motion sickness. Although many may not be aware, the benefits of the space program have impacted most everyone on Earth; as there have been dozens, if not hundreds of inventions and discoveries which were only developed because of the space program. Although the space program has benefitted humankind, the risks to the fragile human body are gargantuan. It would be preferable to continue the space exploration program remotely via robotics. Introduction Since the middle of the nineteenth century, and perhaps even envision establishing a colony on Planet Mars. And Richard Branson much earlier, mankind has been enthralled by the idea of space of Virgin Atlantic has created Virgin “Galactic”, with plans to allow exploration. Back in 1865, Jules Verne envisioned space travel via any person who has $250,000 to burn to experience space travel a projectile shot at high speed out of a gigantic cannon in “From in the private sector. Earth to the Moon.” In 1901, H.G. Wells envisioned space travel in a space “sphere” in “The First Men on the Moon.” This was closely One thing in common in most of the previously mentioned works followed by the very first science fiction movie: Mieles’ “A Trip to of fiction is that they all seem to imply that it will be pretty easy to the Moon”, a silent movie based on Jules Verne’s earlier tale. get anywhere we want to go in the galaxy and even beyond. What the general public fails to understand, however, is the grim danger Our unquenchable fascination with space travel continues until one faces every moment spent in space. Our bodies are just not this very day. In fact, science fiction movies have been among the created to exist in space. This paper reviews the research con- top grossing movies of all time. One only has to think of the six ducted regarding the many things that can injure, maim or even Star Wars movies (with more episodes coming), E.T., the numer- kill those who dare to travel into space and recommends a safer ous Star Trek series and spinoffs and countless other hugely pop- alternative via robotics. ular fictional productions. Discussion It is even possible that these many popular works of fiction depict- From the very first moment, travel to space is fraught with acute ing the ease of future space travel may have enabled the reality of danger to the human body. The launch of a rocket ship places Nasa’s Project Mercury (1958 – 1963) and the subsequent Apollo unique strains on the body. On Earth, normal gravity conditions space program (1961 - 1975). The dream of space exploration was are termed “1-G”. As the rocket accelerates toward outer-space, further attained in the Skylab project (1973 - 1979), the Mir Space however, the G-forces increase to 3-G or more. An excessive Station (1986 – 2001), in the International Space Station (assem- G-force can have many deleterious effects on the body: The bled starting from 1998; manned since 2000 - present) and the heart loses its ability to pump blood efficiently; circulation of the Space Shuttle Program (1981 - 2011). Our expectation of human blood is impaired and oxygen is prevented from reaching the space travel to alien worlds continues to this day, as scientists brain or other organs sufficiently. Consequently, a decrease in 23 Sara Dina Feinzeig consciousness may occur: Colors may begin to fade; vision may be A study was conducted in the year 2000 on the astronauts of the limited to tunnel vision; and a total blackout may even occur. While Mir Space Station, as well as on astronauts of the International the G-forces usually do not have such serious side-effects at take- Space Station (ISS). Researchers utilized a Dual-energy x-ray ab- off, the effects can be much more severe upon reentry into the sorptiometry (a DEXA scan), which uses laser beams to mea- Earth’s atmosphere since the astronaut’s body is in a much more sure bone density. The DEXA scan results showed a one percent weakened state after a stay in space. (Harrison, 2001) decrease in bone density at the lumbar vertebrae. Furthermore, there was a greater loss in bone mass density at the hip (1-1.6%). On Earth, the average human head weighs approximately ten This decrease in bone density can exacerbate the danger of bone pounds. However, if one experiences 3-G’s, the weight is tripled, fractures. (Carpenter et al, 2010) placing enormous strain on the neck muscles which can result in severe neck pain. Therefore, astronauts are strapped into specially Research conducted on astronauts of Skylab IV who stayed in made seats which provide extra support to sensitive areas, such space for eighty-four days analyzed the calcium loss, which indi- as the cervical and lumbar regions. Astronauts also sit facing the cates bone loss, from their journey. Increasing amounts of calcium direction of acceleration, in order to spread out the forces evenly were secreted in the astronauts’ urine over the duration of the over the body. (Harrison, 2001) first 30 days, after which the loss leveled off. Additionally, the loss of calcium excreted in defecation continuously increased through- Upon reaching outer space, the hazards continue to multiply, but out the journey. Overall, the astronauts lost about 200 mg of calci- for the opposite reason. During takeoff, an astronaut is subject um a day throughout the mission. (Rambault et al,1979) to the force of 3-Gs or more. On the other hand, in outer space there is minimal gravity which can also adversely affect many or- In order to combat bone mass loss by creating artificial mechan- gans of the body. ical stress, astronauts exercise strapped down to a treadmill. The up-and-down movement of running may cause the body to build A major organ which degenerates during space travel is bone. new bone. (Chang, 2014) Although exercise may prevent bone Although bone may seem static, it is actually a dynamic, living tis- mass loss in most of the body, the bones found in the oral cavity sue. There are three types of cells found in bone dynamics: os- cannot be helped by exercise. In fact, jiggling or clenching of the teoblasts, osteoclasts and osteocytes. Osteoblasts are responsible teeth does not cause bone strengthening, but rather bone deteri- for the formation of osteocytes; which are responsible for the oration in that area. Furthermore, as opposed to long bone loss, deposition of bone. Simultaneously, osteoclasts resorb bone. This which can possibly be reversed upon return to Earth, tooth loss coordinated process of bone degeneration and the formation of cannot be. (Stenberg, 2001) new bone is intensified by mechanical stress. (Caetano-Lopes et al, 2007) Therefore, perhaps the most serious hazard faced by as- In order to prevent excessive bone loss in the oral cavity, as well tronauts is the effect of microgravity (very low forces of gravity) as the long bones, astronauts are instructed to consume calcium on the bones of their skeleton.