[image-83]With a Russian spacewalk and the arrival of a European space freighter on tap in the weeks ahead for the International Space Station, the six-person Expedition 40 crew spent the day Tuesday preparing for that excursion and making room for more cargo, all while continuing to support the station’s primary mission of research.
Commander Steve Swanson began the workday transferring urine from a wastewater tank to a recycle tank for the Urine Processor Assembly, part of the Environmental Control and Life Support System that turns wastewater into drinkable water. Or, as former station resident Don Pettit once put it, “It turns yesterday’s coffee into tomorrow’s coffee.”
After inspecting an automated external defibrillator and setting up an alignment guide in the Combustion Integrated Rack for more ground-commanded research into the behavior of ignited fuels in microgravity, the commander packed trash and unneeded items into Orbital Sciences’ Cygnus cargo craft berthed at the station’s Harmony node. Cygnus, which arrived at the station July 16 with nearly 3,300 pounds of science and supplies, will be detached from Harmony by the station’s Canadarm2 robotic arm on Aug. 15 and released by the crew for a destructive re-entry over the Pacific Ocean.
[image-51]With the completion of the latest round of combustion tests for the Burning and Suppression of Solids-II experiment, or BASS-II, Flight Engineer Alexander Gerst removed its hardware from the Microgravity Science Glovebox in the Destiny laboratory. BASS studies the flammability of a variety of materials in space and the best methods for suppressing those fires. Hands-on experiments – especially those that involve setting things on fire – are particularly popular with the astronauts, and Flight Engineer Reid Wiseman jokingly called down to the ground teams that the crew was observing five seconds of silence for the removal of BASS.
Gerst then downloaded data from monitors that he had worn to track his body’s core temperature over a 36-hour period for the Circadian Rhythms study. Because the station orbits the Earth every 92 minutes and experiences 16 sunrises and sunsets every day, the astronauts do not have the same day/night cues that people have on Earth. Results from this investigation will provide insights into the adaptations of the human autonomic nervous system in space and will help optimize crew schedules and workplace illumination.
Afterward, Gerst joined Swanson and Wiseman to review procedures for U.S. spacewalks planned for Aug. 21 and 29.
[image-67]Flight Engineers Alexander Skvortsov and Oleg Artemyev spent their morning gathering tools and hardware for their own spacewalk on Aug. 18. The two Russian spacewalkers will exit through the Pirs docking compartment airlock to deploy a small nanosatellite and configure hardware for future experiment installation on the hull of the Russian segment of the complex.
Meanwhile, Flight Engineer and future station Commander Max Suraev replaced hoses for the toilet in the Zvezda service module.
Following a midday meal, Wiseman and Swanson reviewed training materials for the U.S. spacesuits’ “life jackets” known as the Simplified Aid For EVA Rescue, or SAFER. In the unlikely event a spacewalker becomes untethered during a spacewalk and begins floating away from the station, the small nitrogen-jet thrusters of SAFER would propel the astronaut back to safety.
Wiseman also installed hardware for the Capillary Channel Flow experiment inside the newly vacated Microgravity Science Glovebox. By understanding capillary fluid flow rates in the absence of gravity, scientists and engineers can develop hardware for "pumping" liquids from one reservoir to another aboard spacecraft without the need for a pump with moving parts.
Gerst and Skvortsov teamed up for more docking simulation training as they prepare for the arrival of the European Space Agency’s fifth and final Automated Transfer Vehicle (ATV-5) loaded with more than seven tons of scientific experiments, food and other supplies. The two crewmates will be monitoring the ATV’s final approach for its automated docking to the aft port of Zvezda at 9:30 a.m., Aug. 12.
Nicknamed the “Georges Lemaitre” in honor of the Belgian physicist and astronomer who first proposed the Big Bang theory, the ATV-5 fired its engines twice Tuesday to fine tune its path to the station. The “Georges Lemaitre” is scheduled to fly directly under the station Friday at a distance of 3.9 miles in a test of sensors and radar systems designed to provide data for European engineers’ design of future spacecraft. After Friday’s “fly-under” of the station at 6:45 p.m., the ATV will move in front of the station and transition above and then behind the station for the final four days of its two-week rendezvous. ATV-5 launched atop an Ariane 5 rocket from Kourou, French Guiana, on July 29.