The Expedition 43 crew aboard the International Space Station (ISS) kept busy last week working on a large variety of research and experiments, most of which focused on learning how to improve the health of those living both on and off the planet.
NASA astronaut Scott Kelly worked on tasks related to two investigations last week. He conducted a dry run for the first study, the Japanese Aerospace Exploration Agency’s (JAXA) Nematode Muscles investigation, by starting the growth cycle for the small roundworm Caenorhabditis elegans (which is a commonly used as a model for larger organisms) by transferring the set of worms being used for the experiment to a culture bag. Researchers will study the muscle fibers and cytoskeleton of C. elegans in order to better understand the way these physiological systems change when they are exposed to microgravity. Two sets of worms will be grown on the ISS: one in microgravity, and the other in 1g by putting it in a centrifuge. The purpose of the centrifuge is to mimic gravitational forces as the worms are still in orbit. This will give investigators a way to compare the way different levels of gravity affect the C. elegans samples while they live in space.
Kelly also worked the Space Aging study, which also utilizes C. elegans. Space Aging will observe the way spaceflight affects the way the worms age by recording their movements both in an environment with microgravity and one where gravity is created. Data will be compared to control specimens kept back on Earth. Kelly arranged the samples in their observation units. He then exposed them to microgravity and 1g prior to packing them away to be returned to Earth at a later date.
Back on Earth, similar batches are being grown in a laboratory in Japan so that when the worms in space return, they can be compared to their counterparts on Earth. Data gained from this study may help scientists better understand the molecular changes that happen in the microgravity environment. This could potentially lead to the development of treatments or therapies that may halt physical changes, like muscle atrophy or osteoporosis, that occur during aging and extended bed rest. This research could play a role in future space flight, too, as it may lead to treatments and exercises for crews on long duration missions.
Work was also done by European Space Agency (ESA) astronaut Samantha Cristoforetti on the Osteocytes and mechano-transduction (Osteo-4) investigation. Cristoforetti moved two sets of bioreactors housing samples for the investigation to the Minus Eighty-Degree Laboratory Freezer for the International Space Station (MELFI), in preparation for operations. The samples will stay in the freezer until they are sent back to Earth.
Osteocytes are the most commonly found cells in mature bones. They have the ability to detect mechanical forces, so when stresses are added they can deposit calcium to give support to the bones. They can also weaken the bones when stresses are taken away from it—for example, when microgravity is present. It is known that microgravity—or when a sensation of weightlessness is present—may play a role in the loss of bone density, since osteocytes are not exposed to the force of gravity.
The Osteo-4 study will let scientists gain more knowledge about what happens during this process. It will also give them the opportunity to study changes in the physical appearance and genetic expression of mouse bone cells when they are in microgravity. The results from this study could play a role in helping people on Earth who suffer from broken bones caused by osteoporosis (a disease that causes reduced bone density). Understanding what causes bone density loss in astronauts during their missions could give insight into how to treat bone disorders in people on Earth.
Also last week, the members aboard the ISS worked on several different biological studies. The Sprint Study looks at the ways that high-intensity, low-volume exercise training can be used to play a role in reducing the risk of losing muscle, bone, and cardiovascular functions astronauts may experience when they are in space for long periods of time.
Crew members also worked on checkouts for the Ocular Health investigation. Ocular Health is aimed at helping researchers gain insight into the role spaceflight plays in the vision changes experienced by astronauts. Work was also conducted on the Microbiome Experiment. This investigation looks at how much space travel influences the human immune system and the individual’s microbiome.
NASA astronaut and ISS commander Terry Virts worked last week troubleshooting the airlock in the Japanese Experiment Module to get the ISS prepared for the Robotics Refueling Mission-2 (RRM-2). He also partnered with ground teams later in the week to further prepare the airlock and to ready the slide table that carries the hardware by extending it. NASA and the Canadian Space Agency are working in conjunction on RRM-2. The study looks at different techniques that can be used to repair and service satellites in space. Ground crew uses Dextre, the special purpose dexterous manipulator on the end of Canadarm2, for delicate robotics manipulation. The results from the study will allow engineers to decide if it is feasible to use robots to refuel satellites and test electrical connections.