[image-51]Science and robotics were the focus of activities Tuesday aboard the International Space Station, along with spacewalk preps and systems maintenance to keep the orbiting laboratory in tip-top shape.
Following the Expedition 40 crew’s usual 2 a.m. EDT reveille and a daily planning conference with the flight control teams around the world, Commander Steve Swanson and Flight Engineer Alexander Skvortsov set up an oscilloscope and other equipment for power output diagnostic tests in the Zvezda service module. Over the past two years, the ground team has been tracking fluctuations in the current being fed from two main bus switching units to the Zvezda’s power converters.
Throughout the day, Swanson and Skvortsov relocated an electric current measurement clamp on different wires in Zvezda to enable the team at Houston’s Mission Control Center to track down the cause of the power fluctuations. The NASA astronaut and Russian cosmonaut will wrap up this round of tests on Wednesday.
More hardware that can support another round of tests to isolate the issue will be arriving aboard Orbital Sciences’ Cygnus cargo craft during the Orbital-2 resupply mission, set to launch no earlier than July 10.
Meanwhile, Flight Engineer Reid Wiseman of NASA stowed U.S. tools that had been loaned to his Russian crewmates for a spacewalk last week. During Thursday’s 7-hour, 23-minute spacewalk, Skvortsov and Flight Engineer Oleg Artemyev installed a radar antenna and telemetry system for a technology demonstration, removed and jettisoned an old payload bracket and repositioned its payloads onto a new payload boom.
[image-92]Afterward, Wiseman checked in on the Binary Colloidal Alloy Test, or BCAT, which studies the kinetic behavior of solid materials suspended in a liquid. Wiseman swapped out a camera battery, downloaded images and set a timer for the experiment. Results from this study will help material and industrial scientists develop product formulations to stabilize everyday commercial products.
European Space Agency astronaut Alexander Gerst began his day with the Skin B experiment, which investigates skin aging mechanisms that are slow on Earth but highly accelerated during spaceflight. Results from this study will improve understanding of skin aging as well as provide insight into the aging process of similar body tissues.
Flight Engineer Gerst then prepared some samples in the Microgravity Science Glovebox for a combustion experiment known as the Burning and Suppression of Solids, or BASS. Materials burn differently in the absence of gravity, and some actually become more flammable in space than on Earth. Results from BASS will lead to improvements in spacecraft materials selection and strategies for putting out accidental fires aboard spacecraft. The research also provides scientists with improved computational models that will aid in the design of fire detection and suppression systems here on Earth.
[image-78]After a break for lunch, Gerst, Wiseman and Swanson teamed up to speak with reporters from Univision’s “Contacto Deportivo” and ESPN’s “SportsCenter” to discuss watching the 2014 World Cup games from space and supporting their home countries’ teams in the U.S.A versus Germany match set for Thursday. Gerst, who hails from Germany, joked that if Germany loses the match he would paint a U.S. flag on the side of his shaved head, but if Germany wins his two NASA crewmates would have to shave their heads.
Wiseman and Artemyev later joined up in the Japan Aerospace Exploration Agency’s Kibo module for a test run with a pair of soccer-ball-sized, free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The two crewmates put the mini-satellites through their paces to test all the components of an upcoming Zero Robotics middle school tournament. During these summer games, teams of students from across the country are competing to see who can write the best algorithms to command the SPHERES to perform tasks such as capturing objects with a lasso or maneuvering through a debris field.
Swanson spent his afternoon conducting a vision test and collecting water samples from the internal thermal control system in several station modules. The commander rounded out his day installing a GLACIER freezer in an EXPRESS rack.
Flight Engineer Max Suraev focused much of his time on an inspection of the interior surfaces of the Russian segment of the station. He also performed routine maintenance on the life-support system in Zvezda.
While the crew worked inside the station, robotics officers at Mission Control in Houston completed the relocation of the Flight Releasable Attachment Mechanism, or FRAM, from External Stowage Platform-3 (ESP-3) to ESP-2 as part of the preparatory activities for two U.S. spacewalks to be conducted in August. The FRAM’s relocation sets the stage for the relocation of a failed pump module from its temporary stowage spot on the Mobile Base System to the FRAM on ESP-2. During a pair of spacewalks in December 2013, the Expedition 38 crew swapped out a pump module on the S1 truss and placed the failed unit at that temporary location.
Zvezda’s engines are set to fire Wednesday for the first of two reboosts to place the station in the correct phasing for the launch of the ISS Progress cargo ship on July 23. The 1-minute, 4-second firing will raise the station’s altitude by .3 miles at apogee and 1.9 miles at perigee, leaving the station in an orbit of 262.2 x 254.1 statute miles. The second reboost will be conducted July 17.