Expedition 40 Commander Steve Swanson of NASA and his team of five flight engineers tackled a range of science experiments and supported an upgrade of the International Space Station's computers Tuesday, all while preparing for next week's journey back to Earth for half of the crew after nearly six months in space.

Swanson began the workday by setting up some acoustic dosimeters that he and cosmonaut Max Suraev will wear to track the noise levels they are exposed to for the next 24 hours.

The commander then moved on to the Skin B study as he tested the skin on his forearm with several dermatology tools. Skin B investigates the accelerated aging of skin that seems to occur during spaceflight. Results from this study will improve the understanding of the mechanisms of skin aging as well as provide insight into the aging process of similar body tissues.

Afterward, Swanson joined cosmonauts Alexander Skvortsov and Oleg Artemyev in their Soyuz TMA-12M spacecraft docked to the Poisk Mini-Research Module-2 to conduct leak checks of the Sokol launch and entry suits that the three will wear for the return to Earth.

Swanson, Skvortsov and Artemyev are slated to undock from the station on Sept. 10 at 7:02 p.m. EDT for a parachute-assisted landing in the steppe of Kazakhstan less than 3 0.5-hours later. They have been aboard the station since March 27.

With an eye toward the departure, Skvortsov and Artemyev also spent some time in the morning conducting some preliminary Lower Body Negative Pressure training. The two cosmonauts took turns 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.

NASA astronaut Reid Wiseman started his day by transferring some images from the latest session of the Canadian version of the Binary Colloidal Alloy Test, or BCAT-C1, and stowing the hardware. Results from this investigation of colloids - mixtures of small particles distributed throughout a liquid - will help materials scientists to develop new consumer products with unique properties and longer shelf lives.

Afterward, Wiseman unpacked some new pre-loaded hard drives from the European Space Agency's fifth and final Automated Transfer Vehicle (ATV-5) and installed them in several portable computer system laptops. The ground team then initiated the transition of the station's command and control computers.

Suraev meanwhile initialized some Matryoshka bubble dosimeters and handed them off to European Space Agency astronaut Alexander Gerst, who deployed them in the Harmony node to characterize the radiation environment aboard the station for the RaDI-N study.

Afterward, Gerst talked with reporters from RTL-TV in Cologne, Germany, to provide viewers in his home country with an update on the mission.

http://youtu.be/7fubA64JzlM Watch Gerst's interview with German media

Following a break for lunch, Swanson set up the Portable Pulmonary Function System hardware for the Sprint VO2max sessions that he and Wiseman will conduct this week.

The Sprint experiment measures 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 around 2 0.5-hours every day, and the Sprint team is looking into ways to reduce that total exercise time while maintaining crew fitness.

During the setup of the Sprint hardware, a 50-second delay was added to the communication link between Swanson and the ground team. The Communications Delay Assessment experiment simulates the lag in communications that will exist between Earth and a vehicle on a deep space mission.

Wiseman meanwhile continued swapping out hard drives for the computer system upgrades and setting up hardware for another colloid experiment, the Binary Colloidal Alloy Test-Kinetics Platform. Wiseman and Swanson took a break from their work to talk with students gathered at the INFINITY Science Center, which is the visitor center associated with NASA's Stennis Space Center in Mississippi.

Gerst rounded out his day setting up an armband monitor and other hardware for the ENERGY experiment in which he will be participating this week. In an effort to contribute to crew health and performance as well as to ensure that crew members are getting the proper amount of food and exercise, researchers are measuring how much energy astronauts use during their space missions and tracking changes in their energy balance.

Meanwhile on the Russian side of the complex, Suraev focused on routine activities including the daily maintenance of the life support system in the Zvezda service module.

Skvortsov and Artemyev spent their afternoon drying out and stowing the Sokol suits and gloves that they and Swanson wore earlier. They also pre-packed items for return to Earth aboard their Soyuz.