Thursday, March 26, 2015

The Importance of Bioastronautics for Our Journey to Mars

If we can send landers and rovers such as Viking I, Viking II, and Pathfinder to explore Mars, then why can’t we send humans there as well? Many responses indicate the limited budget of NASA, the heavy weight of humans and the resources that are needed for humans as compared to rovers, and fear of disasters such as those that befell the space shuttles Challenger and Columbia. Although these are all valid concerns, one vital concern that is often not mentioned is the bioastronautics of spacefaring.

This is an example of how Earth's
atmosphere diffuses incoming cosmic
rays, protecting us from these
cancer-causing rays.
Bioastronautics is the study of biological aspects of life in space. Life-threatening situations in space are more than just the asteroid fields and flying debris as depicted in sci-fi films; they also include the damaging effects of cosmic rays and the debilitating effects of microgravity. Cosmic rays are ions, mostly protons, that race through space near the speed of light. While our atmosphere protects us from these cancer-causing rays, in space, astronauts do not have the same amount of matter between them and these ions. When these ions pass through the human body, more ions are created and chemical bonds are broken. A unit of radiation dosage is measured in rem. The average annual cosmic radiation dosage received by a human on Earth is 0.03 rem. On a trip to Mars, astronauts would receive as much as 80 rem a year. This amount of radiation would induce cancer as well as cataracts and brain damage. Solar flares also produce dangerous bursts of protons and heavy nuclei. These bursts can deliver a radiation dose in the hundreds of rem in an hour or so- “a lethal dose for unshielded astronauts.”

Microgravity is another concern for NASA’s astronauts. Initial symptoms of microgravity include disorientation, pallor, malaise, loss of motivation, irritability, drowsiness, stomach awareness, and infrequent but sudden vomiting. These symptoms usually fade away in two to three days; however, the lasting effects of bone degeneration continue throughout the time astronauts are in space. Calcium eliminated through urination and defecation causes up to three hundred milligrams to be lost per day. Although it is still unclear whether acute calcium loss is completely reversible, there are exercises and diets given to astronauts to minimize calcium loss in space. To be sure, bone decalcification has few consequences in space; the major concern is the return of astronauts to Earth’s gravity. If humans were to colonize Mars, which has about one-third the gravity of Earth, they would be subjected to the effects of Mars' light gravitational pull over their entire lifetimes. Prolonged exposure to such conditions on the human body has yet to be tested.

In order to research these effects, on September 11, 2014, NASA increased its contract with Wyle Integrated Science and Engineering Group of Houston from $75 million to almost $1.5 billion. Wyle is a leading provider of specialized engineering, professional, scientific, and technical services to the federal government, and is the number one life-services provider to NASA. As listed on their website, one of Wyle’s primary responsibilities to NASA is to “investigate operationally relevant environmental issues associated with human space flight.” The twenty-fold increase in the budget outlay from NASA to research bioastronautics will hopefully allow us to venture to Mars in the near future.

- Siqi Yang