[image-51]The six-person Expedition 40 crew of the International Space Station delved into a number of scientific experiments and health investigations Wednesday and trained for the robotic capture of a U.S. commercial cargo spacecraft.
Commander Steve Swanson began the workday checking his blood pressure for the ongoing Ocular Health study. NASA recently identified that some astronauts experience changes in their vision, which might be related to effects of microgravity on the cardiovascular system. In space, the body’s fluids tend to move toward the upper body and head and cause the pressure in the skull to rise. The increased pressure from the cranium travels down the optic nerve and affects the eye. NASA is working to understand and prevent these changes in astronauts, which in turn may help doctors diagnose and treat related vision changes here on Earth.
Swanson’s fellow NASA astronaut aboard the station, Flight Engineer Reid Wiseman, also focused on health as he conducted an ultrasound scan of the calf and thigh of his right leg for the Sprint exercise investigation. The researchers behind Sprint are measuring the effectiveness of high-intensity, low-volume exercise training in minimizing the loss of muscle mass and bone density that occurs during spaceflight. Station crew members currently work out about 2 ½ hours every day. By reducing the amount of time spent exercising while still maintaining physical fitness, the crew will have more time to focus on station research and technology.
Meanwhile in the station’s Kibo module Flight Engineer Alexander Gerst worked with the Ice Crystal 2 experiment, which investigates the growth rates and stability of ice crystals in super-cooled water that contains a substance known as antifreeze glycoprotein. Biological antifreeze, which prevents the formation of ice crystals even in freezing water, is found in several species of fish in polar environments. Understanding how antifreeze glycoprotein works could lead to new research in the fundamental physics of crystal growth.
Afterward, Gerst transferred a multi-purpose experiment platform and a robotic arm known as the Small Fine Arm through the Kibo module’s scientific airlock. The Small Fine Arm, which attaches to the Kibo’s larger main arm, handles delicate operations involved in exchanging experiments and payloads located on the Exposed Facility.
[image-67]After a break for lunch, Swanson, Wiseman and Gerst teamed up to train for the robotic capture of Orbital Sciences’ Cygnus cargo craft, set to launch on the Orbital-2 commercial resupply services flight no earlier than July 10. When Cygnus approaches the station several days after its liftoff from the Mid-Atlantic Regional Spaceport at NASA's Wallops Flight Facility in Virginia, the crew will use the 57-foot Canadarm2 robotic arm to reach out and grapple the vehicle for its berthing to the Earth-facing port of the Harmony node.
Swanson and Wiseman took a break from their work to talk with students and educators gathered at the Reuben H. Fleet Science Center in San Diego. The two astronauts answered questions and discussed how research conducted in space benefits humankind. The 20-minute space chat kicks off a series of events planned as part of Destination Station: San Diego – a new NASA multimedia exhibit at the Fleet Center.
Wiseman rounded out his day donning sensors and an armband monitor 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, an astronaut’s body clock can get disrupted by experiencing 16 sunrises and sunsets every day. 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.
On the Russian side of the station, Flight Engineer Oleg Artemyev participated in the Virtual experiment, which looks at changes to a cosmonaut’s spatial orientation during a long-duration space mission. He also performed routine maintenance on the life-support system in the Zvezda service module and completed some Crew Medical Officer proficiency training.
[image-94]Flight Engineers Alexander Skvortsov and Max Suraev inspected the shell of the Russian segment using an eddy-current testing device to detect any flaws in the surfaces.
Skvortsov also reconfigured the work area in Zvezda following the completion of two days of power diagnostics that he conducted with Swanson. Over the past two years, the ground team has been tracking fluctuations in the electrical current being fed from two main bus switching units to Zvezda’s power converters. Throughout the past two days, Swanson and Skvortsov set up an oscilloscope and placed 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. More hardware that can support another round of tests to isolate the issue further will be arriving aboard Cygnus.
While the crew members worked Wednesday, their high-flying laboratory was reboosted even higher to support the arrival of a Russian cargo ship next month. The engines of Zvezda were fired at 6:41 a.m. EDT for one minute and four seconds to place the station in the correct phasing for the launch of the ISS Progress 56 cargo ship on July 23. The reboost raised 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. A second reboost will be conducted July 17.