SPACE STATION WEEKLY UPDATE Feb. 16 – Feb. 22, 2015: Last week the astronauts aboard the Internation Space Station (ISS) kept a very busy and exciting schedule. Plant studies, imaging operations, and maintenance to some of the station’s ongoing research took place. In addition, members aboard the space station sent a cargo vehicle back to Earth for its final descent, and welcomed a new cargo vehicle full of supplies. To top it off, two of the astronauts took a walk in the vacuum of space to prepare the ISS for future deliveries of commercial crew traffic.
The first set of samples in the Japanese Aerospace Exploration Agency’s (JAXA) Plant Circumnutation and its Dependence on the Gravity Response (Plant Rotation) investigation were tended to by NASA astronaut Terry Virts, when he watered them for the study. Circumnation is a type of plant growth where the specimen bends so that it grows in a spiraling shape. The Plant Rotation study will investigate whether or not microgravity has any kind of affect on the circumnation of rice and morning glory plants under camera observation as they are grown under specific lighting conditions while aboard the ISS. Scientists will then study downlinked images to learn if circumnutation is dependent on gravity by measuring plant growth, along with the way the plants move as they grow.
When plants grow in a spiral, there are several different variations in how the spiral can be shaped, from tight loops to broad curves. It is hoped this study will help scientists create a model to grasp the molecular features of this type of growth behavior. The insight gained from this study will give future astronauts on deep space missions tools to understand how to better grow their own food in microgravity, since they will learn how circumnation works on different plants. It will also help on Earth, as the information gained from this investigation could lead to the development of new techniques that would allow the growth of certain food crops in smaller spaces, or how to generate more product while using less fertilizer.
The next round of imaging operations were conducted by European Space Agency (ESA) astronaut Samantha Cristoforetti for the Bone Densitometer Validation study. Since the loss of bone density is a commonly known side effect of traveling in space due to microgravity, an X-ray device the size of a microwave oven was developed to analyze measurements collected on bone density, muscle, and fat loss on mice aboard the space station. Initially, the mice were scanned at Kennedy Space Center just prior to being delivered to the ISS on Space-X’s Dragon spacecraft for the fourth Commercial Resupply Mission (CRS-4). Once they arrived and were unloaded, they were again scanned to be sure the scans were identical to validate the device. During the study, the astronauts will periodically scan the mice and deliver the information back to the scientists on Earth participating in the investigation.
The results will be used to fight bone density loss in both astronauts and people on Earth. Though long-duration space crews exercise often and eat healthy to combat bone density loss, missions that will one day require astronauts to stay in space for a year or more will need additional ways to keep crew members in good health. Results from this investigation will also help to test new therapies and create new ways to treat bone density loss in millions of elderly patients on Earth battling osteoporosis, along with a multitude of other bone density-related issues.
A battery charge and intervalometer change took place last week, thanks to NASA astronaut Barry “Butch” Wilmore for the Binary Colloidal Alloy Test Low Gravity Phase Kinetics-Critical Point (BCAT-KP) study. BCAT-KP investigates core behaviors of colloids (mixtures of small particles distributed throughout a liquid). The mixtures included are substances such as milk, detergents, and liquid crystals. Phase separation of liquids and gasses is almost always highly affected by sedimentation when gravity exists because gasses are typically less dense than other liquids that are formed by the same material. Since the processes are very slow, observing a full run of phase separation is not observable in an environment with gravity without having sedimentation occur, affecting the process.
The results that show how colloids function in microgravity will help researchers improve products on Earth, due to the fact that gravity determines the manner in which the particles bind together and sink. Additionally, it will refine computer models created to replicate how colloids behave in microgravity.
On Feb. 14, at 8:42 a.m. the fifth and last of ESA’s Automated Transfer Vehicles (ATV) detached from the ISS at its aft port of the Zvezda service module, so that it could deorbit after being moved away from the space station, followed by its destruction upon re-entry. It went out in flames, as it burned up in Earth’s atmosphere over the Pacific Ocean at approximately 12:12 p.m. on Sunday, Feb. 15, concluding a seven-year era of European space freighter supply to the ISS. Since the external cameras on the ISS were not able to capture the event, the station’s commander, Barry “Butch” Wilmore, let NASA know via radio communications that he documented the conclusion of the ATV with still and video cameras, since he was able to observe a plasma trail created by the vehicle’s descent.
On the same day, the Russian ISS Progress 58 cargo craft was rolled out to the launch pad at the Baikonur Cosmodrome in Kazakhstan, in freezing temperatures and fog. It launched Tuesday, Feb. 17, at 6:00 a.m. EST. The ship docked with the ISS at the rear port of the Zvezda module, where it will stay docked until August, at 11:57 a.m. EST, delivering three tons of food, fuel, supplies, and experimental hardware to the astronauts waiting on the station.
Also last week, the first of three spacewalks concluded Saturday, Feb. 21, at 2:26 p.m. when Wilmore and Virts completed all of their scheduled tasks, along with one extra task to get them ahead of schedule. The pair worked to set up a series of power and data cables on the forward end of the Harmony module and Pressurized Mating Adapter-2, where they installed 340 of 360 feet of cable as part of a plan to reconfigure station systems and modules for the delivery of new docking adapters for use by future commercial crew vehicles during this decade, when they begin to send astronauts to the ISS.
This spacewalk, EVA-29, marked a total of 13 hours and 15 minutes spent in space by Wilmore, as well as the first spacewalk for Virts, which in total lasted 6 hours and 41 minutes. The pair will perform a second spacewalk (EVA-30) on Wednesday, Feb. 25, at 7:10 a.m., to perform additional tasks, which include installing two more cables and lubricating the end of the robotic arm on the space station.