[image-78]The International Space Station’s Expedition 38 crew supported a wide range of experiments Tuesday while three crew members get set for their journey back to Earth after nearly six months in space.
Flight Engineer Mike Hopkins spent a good portion of his day in the Kibo laboratory as he removed hardware for the most recent iteration of the Marangoni experiment from the Fluid Physics Experiment Facility. The crew will set up the facility for another Marangoni experiment later this week. By conducting these experiments in microgravity, researchers hope to learn more about the underlying principals of Marangoni convection, which is the flow driven by a surface tension gradient caused by the temperature difference of two liquids. Results from this study may also lead to the production of semiconductors and optical crystals and contribute to various micro-fluid handling techniques, such as those used in DNA examination and clinical diagnostics.
Hopkins teamed up with Flight Engineer Rick Mastracchio to set up new test samples for the Binary Colloidal Alloy Test, or BCAT, which studies how crystals form from solid materials suspended in a liquid. Results from BCAT will help researchers develop new colloidal materials and formulations with unique properties. The two NASA astronauts homogenized the samples and set up a camera system to take automated photography of BCAT’s progress.
Hopkins also collected biological samples for the Microbiome study, which takes a look at the impact of space travel on the human immune system and an individual’s microbiome -- the collective community of microorganisms that are normally present in and on the human body. In addition to providing data that will keep future crews healthy, findings from this study could benefit people on Earth who work in extreme environments and further research in the detection of diseases, alterations in metabolic function and deficiencies in the immune system.
[image-51]Flight Engineer Koichi Wakata of the Japan Aerospace Exploration Agency began his day reconfiguring the slide table of the Kibo module’s scientific airlock following last week’s completion of the deployment of a fleet of miniature satellites. Throughout the past few weeks, batches of NanoRacks CubeSats have been passed through the airlock while installed on a deployer mechanism on the Multi-Purpose Experiment Platform and launched into orbit from the side of the station.
Afterward Wakata and Mastracchio relocated a remote flow control assembly in one of the cooling loops inside the station’s Destiny laboratory to support the relocation of one of the station’s research freezers known as a Minus Eighty-degree Laboratory Freezer for ISS, or MELFI.
Wakata and Mastracchio rounded out their workday with another round of exams for the Ocular Health study. Vision changes have been observed in some astronauts returning from long-duration spaceflight, and researchers want to track down the root causes of this change and develop countermeasures to reduce the risk. With assistance from the Ocular Health team on the ground, Mastracchio collected detailed imagery of Wakata’s eyes using optical coherence tomography equipment and a fundoscope.
On the Russian side of the complex, Commander Oleg Kotov and Flight Engineer Sergey Ryazanskiy focused most of their attention on preparations for Monday’s departure aboard a Soyuz spacecraft. The two cosmonauts and Hopkins are scheduled to undock from the station March 10 at 8:02 p.m. EDT aboard their Soyuz TMA-10M spacecraft and land southeast of the town of Dzhezkazgan in Kazakhstan at 11:24 p.m. (9:24 a.m. March 11, Kazakhstan time). They arrived at the space station back on Sept. 25 less than six hours after launching from the Baikonur Cosmodrome in Kazakhstan.
Kotov and Ryazanskiy each participated in the Lower Body Negative Pressure test by donning a special outfit that simulates the effects of gravity by drawing fluids to the lower half of the body. In addition to conditioning cosmonauts for the return home, this device provides Russian researchers with data to predict how the cosmonauts will react to the full force of Earth’s gravity at the end of their mission.
The two cosmonauts also conducted a descent drill to remain prepared for any contingencies during the trip back to Earth and reviewed the cargo stowage plan for their Soyuz spacecraft. Once that was completed, Kotov continued gathering research samples and personal gear to be stowed in the Soyuz.
The third Russian cosmonaut aboard the station, Flight Engineer Mikhail Tyurin, performed a check of the Zvezda service module to detect any harmful contaminants. Tyurin also conducted routine maintenance on the Elektron oxygen-generating system and the life support system in Zvezda.
[image-94]The departure of Kotov, Hopkins and Ryazanskiy will mark the end of Expedition 38 and the beginning of Expedition 39 under the leadership of Wakata, the first Japan Aerospace Exploration Agency astronaut to command the station. Kotov will pass the helm to Wakata during a Change of Command ceremony slated for 4:50 a.m. Sunday. Wakata, Mastracchio and Tyurin, who arrived at the orbiting complex Nov. 7, will remain aboard the station until mid-May.
Meanwhile the three flight engineers who will return the station’s crew to its full six-person complement are in their final month of preparations for launch. NASA astronaut Steve Swanson and Russian cosmonauts Alexander Skvortsov and Oleg Artemyev began the first of two days of final qualification exams Tuesday at the Gagarin Cosmonaut Training Center in Star City, Russia. On March 13, they will fly to the launch site in Baikonur to begin the final phase of training for their launch on March 25 aboard the Soyuz TMA-12M spacecraft.