Mankind is not built for life in space. This is one of the fundamental truths that we have been forced to come to terms with during the short period in which humanity has frequented low-Earth orbit. In an effort to better understand the detrimental effects of microgravity on the human body, the Japanese Aerospace Exploration Agency (JAXA) is conducting a pair of experiments centering around observing the tiny roundworm, Caenorhabditis Elegans.
Currently, astronauts are forced to undertake time-consuming workouts using specialized equipment on a daily basis during their time aboard the ISS, in an attempt to mitigate the detrimental effects of microgravity. However, regardless of the precautions taken, the average astronaut will return to Earth having suffered an average loss of one to two percent of overall bone mass for each month spent aboard the station.
Research is being carried out on a global scale to tackle the issue, with top scientific facilities such as ESA's Antarctic Concordia base conducting muscle loss studies, as well as educational institutions like King's College London developing skinsuits designed to simulate the effects of Earth's gravity.
Caenorhabditis elegans was chosen as the specimen for the study, as its physiology can be used as a small-scale model of the muscle and bone composition of larger animals such as human beings. At less than 1 mm in length, the round worm has a number of advantages over other live animal specimens – for example, the short life span of the species (roughly 2-3 weeks in a laboratory environment) allows astronauts to cultivate several generations whilst aboard the station.
JAXA hope to capitalize on this trait by observing how genetic adaptation to the microgravity environment prevailing on the ISS progresses on a cellular level from generation to generation. "The astronauts will cultivate multiple generations of the organism, so we can examine the organisms in different states of development," states Atsushi Higashitani, principal investigator for the projects with Tohoku University, Japan. "Our studies will help clarify how and why these changes to health take place in microgravity and determine if the adaptations to space are transmitted from one cell generation to another without changing the basic DNA of an organism. Then, we can investigate if those effects could be treated with different medicines or therapies."
A second experiment due to launch to the station aboard a SpaceX Dragon resupply mission later this year, will seek to asses the shorter term issues of living in space – the degradation of muscle and, in the case of the worm, cytoskeleton (the equivalent of human bone matter). For the purpose of the experiment, one group of worms will be cultivated in the standard microgravity environment characteristic of low-Earth orbit, whilst another is raised in a 1G centrifuge designed to simulate the effects of Earth's gravity aboard the station.
The various experiments will then be returned to Earth, whereupon they will be examined and compared to Caenorhabditis Elegans raised in a terrestrial Japanese lab.
The potential future applications of bone and muscle loss research will be vital to the success of any manned mission to Mars or beyond, but it will also be invaluable to people back on Earth with similar ailments. Individuals suffering from a condition that results in prolonged bedrest, or even the diminutive effects of aging, could have their quality of life greatly improved as a result of the research carried out aboard the ISS ... thanks in part to the little worm Caenorhabditis Elegans.