The six Expedition 43 crew members currently living and working on the International Space Station (ISS) kept a busy schedule last week. In addition to the work they did with ongoing science experiments and research the crew also received a fresh cargo delivery of supplies and new science experiments with the arrival of the SpaceX CRS-6 Dragon.
Last week, the Bone Densitometer was calibrated by NASA astronaut Terry Virts in preparation for the Rodent Research-2 study. Created by Techshot, Inc., the Bone Densitometer x-ray device, which is about as large as a typical microwave oven, is used to take X-rays to measure bone density, muscle, and fat of mice being studied as part of the investigation while on the space station. It is hoped that this testing will show it can be used on humans while on spaceflights.
Despite daily exercise and healthy meal options to stop it in its tracks, astronauts that participate in long-duration space travel will see a decrease in bone density. Scientists will use the results from the mice they observe in the Rodent Research-2 investigation to create treatments for people in space and on Earth that suffer from bone density loss. This is especially crucial for crew members that take part in long-duration spaceflight missions in the future, since practices will need to be added to ensure their continued good health.
Although the Bone Densitometer is being used to study bone density loss on humans in a space environment, once researchers and biotech companies see that it does work properly, they can look at creating new therapies that may help the millions of people on Earth that have illnesses stemming from bone-density problems, such as osteoporosis.
Work was also done last week on NASA’s Binary Colloidal Alloy Test Low Gravity Phase Kinetics-Critical Point (BCAT-KP) study. European Space Agency (ESA) astronaut Samantha Cristoforetti worked on transferring images, changing batteries, setting the intervalometer, and aligning and focusing the camera. The ground teams for the BCAT investigation confirmed receipt of the downlinked images from the ISS and higher image quality.
The BCAT-KP investigation looks at core behaviors of colloids (mixtures of small particles distributed throughout a liquid). These mixtures include substances like milk, detergents, and liquid crystals. Sedimentation almost always largely affects phase separation of liquids and gasses when there is gravity due to the fact that gasses are usually less dense than other liquids formed by the same material. Observing a full run of phase separation is not possible in an environment where there is gravity because the processes are so slow that sedimentation will occur.
Since gravity determines the manner in which the particles bind together and sink, results showing the way colloids function in microgravity will assist scientists in improving products on Earth. The information learned will also refine computer models created to replicate the behavior of colloids in microgravity. It also may possibly aid in the creation of new consumer products, some of which may be manufactured in space thanks to reduced costs and longer life-span.
Also last week, the 28th and 29th runs of a planned 30 were finished by scientists on the ground for the Japan Aerospace Exploration Agency’s (JAXA) Experimental Assessment of Dynamic Surface Deformation Effects in Transition to Oscillatory Thermo capillary Flow in Liquid Bridge if High Prandtl Number Fluid (Dynamic Surf) investigation. This experiment is part of a larger overall set of experiments that will study a specific kind of heat transfer known as “Marangoni convection”, which happens when there is a difference in temperature between a liquid and a gas. A silicone-oil mixture will be heated to observe the way it changes in hopes of learning how heat transfers in microgravity. Once silicone oil is suspended between two small, solid disks, one disk will be heated while the other is cooled to slowly create an increasing difference in temperature over the liquid. Turbulence will increase as the convective force called the Marangoni flow takes place.
During the runs last week, the world record for the Marangoni experiment was achieved when the largest silicon oil bridge ever acquired was completed with an aspect ratio of 2.8 (this is a ratio of liquid length 28mm to diameter 10mm).
Information learned by researchers will be important for industrial processes and fluid physics. It could also help to create more effective designs for space systems that are fluid based and lead to better research on the growth of high-quality crystals similar to those used on semiconductors and optics and in several different micro-fluid applications (like DNA examination) on the space station and Earth.
The Dragon CRS-6 spacecraft arrived at the ISS on Friday, April 17, 2015, just days after launching atop a Falcon-9 rocket from Cape Canaveral, Fla. As the space station passed over the Pacific Ocean slightly east of Japan, Cristoforetti, assisted by Virts, captured the capsule with the Canadarm2 robotic arm at 6:55 a.m. EDT. At 9:29 a.m. EDT, Dragon was connected to the Harmony module of the ISS.
Dragon will stay attached to the station for approximately 5 weeks before its departure. It delivered over 4,300 pounds of supplies, experiments and technology demonstrations, including materials which will be used on approximately 40 of the over 250 investigations planned for Expedition 43 and 44. Crew supplies included the first espresso machine – appropriately named the ISSpresso – which will be used by the crew to make espresso, tea, and other hot drinks.
The ISS will receive more supplies when the Progress 59 cargo resupply ship takes off out of the Baikonur Cosmodrome on April 28, 2015 at 3:09 p.m. The launch will be followed by the spacecraft’s arrival at the ISS, where it will dock to the Poisk module about six hours after.
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