Artificial Gravity in a Zero Gravity Environment: An Interdisciplinary Analysis

Mars as Viewed from Earth
Courtesy of Linda Tanner (Flickr.com)

In 2010, The National Aeronautic and Space Administration (NASA) officially declared a manned mission to Mars a long-term goal. The agency claims that they can be ready and technically capable of sending humans to an asteroid in 2025 and to the red planet as early as 2030. We as a people have sent numerous orbiters, landing craft, and rovers to Mars and have been attempting to explore the Martian surface since the 1970s. Sending a manned mission to Mars seems to be the next major step in the study of our second closest planetary neighbor and the next step in NASA’s and mankind’s exploration of our solar system. A flight to Mars and back would, as most experts agree, take a minimum of 500 days to accomplish with seven or eight months in flight time there and back. Aside from the near impossible technological considerations associated with landing a spacecraft on the Martian surface gently enough to not put the crew on board in danger and can actually take off again and return to earth, there is debate over how a crew would function after multiple 7 month spaceflights. The concern for this stems from the lack of sufficient gravitational pull during the trip, generating a, for all intents and purposes, weightless environment. This prolonged exposure to lack of gravity has very adverse effects on the human musculoskeletal system and is a major roadblock for any sort of distance space mission. For a spaceflight like this, many scientific disciplines would need to come together in perfect harmony to accomplish the goal. There are many scholarly articles dedicated to researching the problem of microgravity but I will specifically be analyzing and discussing how a physiological essay and a technical theoretical physics essay each approach the issue. The two articles, while both scholarly, use very different structural, linguistic, tonal, and visual methods to present their similar claims that longterm exposure to microgravity is extremely detrimental to human health and more research needs to be conducted on the methods of which to counteract it.

The two said scholarly articles I will be analyzing are titled “Effects of long-term spaceflight on mechanical properties of muscle in humans” written by Daniel Lambertz, Chantal Pérot, Rustem Kaspranski, and Francis Goubel, a study from the field of physiology, and “Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions” by Gilles R. Clément, Angelia P. Bukley, and William H. Paloski, a theoretical physics piece. To better understand how the different rhetorical devices within the two pieces are used, it’s important to understand where these scholarly articles sit in context with the topic of microgravity. The first article, the one viewing the issue from a medical perspective, consists of an original study conducted on 14 astronauts that compared the flexibility of the plantar flexor muscles the enable your foot to move up and down at the ankle. The study yielded findings that not only do muscles undergo muscular atrophy throughout the body, joint flexibility and range of motion decreased by 25 percent on average. The second piece delves into the technological advancements that could be implemented to counteract the effects of a zero gravity environment. The article uses a quite theoretical approach, usually basing their argument off physics, to criticize and raise necessary questions concerning the practicality of many common proposed solutions to the problem.

At first glance, taking both articles at face value, the authors of these pieces quickly establish their credibility in their respective fields in slightly different ways. The two articles are similar in the way that they are both written in your typical scientific, scholarly journal format. They begin with a summarizing abstract, progress to an introduction, and then proceed to weave through any quantitative data, measurements, observations, and experimental procedures. Your typical academic minded article closes with an all encompassing conclusion and ties the authors entire argument into a single cohesive section summarizing all the data into a disputable claim, and these articles are no exception. When discussing the rhetorical devices and techniques scholarly writers use to prove a point, the structure of the writing is an undeniably sizable portion to that. Laying out an argument in this way provides a roadmap to the researcher’s conclusion, something particularly useful in academic writing. This is particularly apparent and a necessary component of the first physiological study mentioned above. “Effects of long-term spaceflight on mechanical properties of muscle in humans” contains a quite complex set of mathematical algorithms for interpreting their data, with methods that might not be easily explained to other researchers in that field, let alone a general audience. The organizational structures chosen by the researchers on the project help keep their argument in as simple of terms possible, helping to not unnecessarily overcomplicate their concept. Consequently, this style of writing is very advantageous to most disciplines that engage in heavy academic topics. This sort of structure is advantageous to the technological paper as well in a unique way. The authors for “Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions” use a modified version of the common scientific scholarly format, slightly different than the first article, by creating an introduction, theoretical data set, and a conclusion under all three subtopics in the essay. These three subtopics are all included under the umbrella of the paper’s main topic of artificial gravity. This gives the claims concerning every method of creating artificial gravity discussed a very organized and constructed feel. Even though they implement the structure slightly differently, these scholarly articles establish credibility by explaining their data in a clear and logical manner. They create strong, clearly defined points, making it difficult to argue against their findings.

The nature of the content of these academic pieces strongly influence the way the authors establish their points. Both the articles, as most journals in the scientific community do, successfully explain very complex and abstract ideas. A feature that should be noted in both essays is the use of data tables, diagrams, and other visual aids to help readers, experts or not, further understand the topic. This could be exemplified in the technological paper specifically when the authors begin to explain the directional forces that would occur when astronauts would use a short range centrifugation machine. In context, a short range centrifugation machine (SRC) is a contraption that would spin a human around about a 20 foot radius while on a spacecraft. The hypothesis is that if the device were to be used for around 20 minutes a day, that would be sufficient enough to counteract the onset of the detrimental musculoskeletal effects of zero gravity. While describing how the SRC directional forces would not be the same on earth as they would in a zero gravity environment, rather than explaining the physics equations and the phenomenon of centripetal force in words, the force diagrams provided help readers to visualize the concept. These types of articles are rarely read by anyone besides other scholars in that field who are usually familiar with the content. However, the idea to academic journal is to share information within their respective discipline, and making anything more complicated than it needs to be is counterproductive to the overall goal of that discipline. The physiological paper approaches visual aids in a different way, providing charts and data sets to make they’re incredibly dense experiment more tangible. The authors of that paper included nine graphs, all of which corroborated their main claim of how exposure to a zero gravity environment specifically in the context of space causes joint stiffness and severe muscular atrophy. Aside from helping readers comprehend information, their visual aids help with the overall professionalism of the pieces and I think visual formatting and data presentation is critical in all writing and especially in scholarly work to promote believability and to have your ideas be worth considering.

The authors of both papers established their ethical credibility and their logical methods with the article structure as well as the visual aids presented and they continue to do so in the actual linguistics within the papers. I find the tone of the technological critique of artificial gravity to be the most fascinating. The authors of the piece took it upon themselves to use more of a candid approach to their writing. This is somewhat unusual in the field of theoretical physics since their studies are, after all, theoretical. One would expect a theoretical physicist to be more optimistic about the possible extreme solutions to microgravity, such as the idea of rotating spaceships. However, the researchers in this article provide a unique perspective seeing as they pointed out many issues with most of the proposed solutions. As seen in the quote “questions such as what are the impacts of centrifugation inside a space vehicle on the vibration level, motion sickness, or crew time need to be addressed by use of a human-rated centrifuge” (Clément), the lack of unrealistic or somewhat unverified data that can be found in some theoretical physics papers helps make the researcher's ideas on these topic more practical and credible. At the same time, the pointing out of errors in assumptions leads to a more constructed argument for furthering the research in developing artificial gravity rather than simply saying that countermeasures exist. The physiological journal employs a more serious tone offering countless equations and mathematical formulas to model their data of increased tension in musculoskeletal joints after spaceflight. This is abundantly apparent throughout the paper in a quote such as “mean MVC [maximum voluntary contraction (the distance you can bend your foot upward at the ankle)] was found to be significantly higher in preflight condition than in postflight condition (108.90 ± 19.70 vs. 90.90 ± 26.48 N · m)” (Lambertz). While it is understood that for a research paper that reports vast amounts of data straight from an experiment, a full, overly descriptive means and methods situation is necessary. However, while it is necessary to make sure an experiment is repeatable by another party, some of the mathematical explanations were redundant. After the data sets were compiled and represented in graphs, the eventual excessive calculations in sentence form I felt were unnecessary since the paragraph form discussion section and conclusion provided a much more useful data interpretation than a mathematical model can show. In other words, linguistically, The theoretical article takes a more of a “layman’s terms” approach while still maintaining its scholarly integrity, whereas the physiological article takes a much more mathematically in depth approach as is more common in the medical field.

The Discovery Space Shuttle. Similar to what Clément

discussed, in the early 2000s many scientists

hypothesized that the shuttle could be kept in perpetual

rotation to induce artificial gravity

Courtesy of Rob Shenk (Flickr.com)

Both these papers do a fantastic job corroborating their argument by using various rhetorical devices and techniques structurally, linguistically, tonally, and visually. If you wanted to quickly summarize the difference in their respective rhetorical techniques, you could say that one is more scientifically rigid than the other. What I mean by this is that the physiological article uses a much more concrete format to convey their argument on the degeneration of muscles and the increase in joint stiffness. There is really not much of a way to refute a mathematical model and the paper consequently follows a very narrow path as would be expected from an essay based on data collection alone. Conversely, the theoretical essay offers more of a discussion for how research in the field of artificial gravity can be improved and built upon. Even though the articles and disciplines are very different, they employ some rhetorical devices similarly and some dissimilarly. They both establish and arrive the same conclusion - that more research needs to be done in the field of artificial gravity to find a viable option to satisfy both disciplines, medically and technically.

Works Cited

Daniel Lambertz, Chantal Pérot, Rustem Kaspranski, Francis Goubel, “Effects of long-term spaceflight on mechanical properties of muscle in humans”, Journal of Applied Physiology, Vol. 90, No. 1 (2001): 179-188

Gilles R. Clément, Angelia P. Bukley, William H. Paloski, “Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions”, US National Library of Medicine and National Institutes of Health, Vol. 9, (2015)

Alan Sternberg, “Space policy responsiveness: The relationship between public opinion and NASA funding”, Space Policy, Vol. 27, Issue 4 (2011): 240-246
doi:10.1016/j.spacepol.2011.07.003

Kenneth S. Casey, “The Past, Present, and Future of the AVHRR Pathfinder SST program”, Oceanography from Space, (2010): 273-287
doi:10.1007/978-90-481-8681-5_16

Bethany L. Ehlmann, “Humans to Mars: A feasibility and cost-benefit analysis”, Acta Astronautica, Vol. 56, Issues 9-12, (2005): 851-858
doi:10.1016/j.actaastro.2005.01.010

A.A. Edwards, “RBE of radiations in space and the implications for space travel”, National Radiological Protection Board, (2001): 147-152

Shreyasee Amin, “Mechanical Factors and Bone Health: Effects of Weightlessness and Neurologic Injury”, Current Rheumatology Reports, Vol. 12, Issue 3, (2010): 170-176

Peter Suedfeld and G. Daniel Steele, “The Environmental Psychology of Capsule Habitats”, Annual Review of Psychology, Vol. 51, (2000): 227-253

Shreyasee Amin, “Mechanical Factors and Bone Health: Effects of Weightlessness and Neurologic Injury”, Current Rheumatology Reports, Vol. 12, Issue 3, (2010): 170-176