Biomedical research and preparations for the departure of three crew members were the focus of activities Wednesday aboard the International Space Station as the six Expedition 40 astronauts and cosmonauts head into their final week together in space.

Commander Steve Swanson of NASA and his team of five flight engineers began the day with the usual 2 a.m. EDT reveille followed by a daily planning conference with the flight control teams around the world.

Afterward, Swanson downloaded the data from acoustic dosimeters that he and cosmonaut Max Suraev wore for the previous 24 hours. Swanson then swapped out the batteries and handed off the dosimeters to European Space Agency (ESA) astronaut Alexander Gerst and cosmonaut Oleg Artemyev for another 24-hour data collection period to help spacecraft designers learn more about the sound levels the crew is exposed to throughout the day.

With an eye toward the end of his long-duration stay in space, Swanson spent some time packing up his remaining crew provisions, with some of the items slated to be loaded into the Soyuz TMA-12M spacecraft that will return Swanson, Artemyev and Soyuz Commander Alexander Skvortsov to Earth next week.

The trio will undock their Soyuz from the Poisk module on the space-facing side of the station on Sept. 10 at 7:02 p.m. for a parachute-assisted landing in the steppe of Kazakhstan less than 3 0.5-hours later.

Skvortsov spent much of the morning stowing items in the Soyuz, while Suraev and Artemyev recharged the satellite phone that will be carried aboard the returning Russian spacecraft.

Artemyev then moved on to some experiment work, including the SPLANH study which takes a look at the effects of spaceflight on the digestive system. Skvortsov meanwhile set up a portable HD camera inside the Soyuz to record the descent.

NASA astronaut Reid Wiseman began the day with an exercise session on the COLBERT treadmill while wearing medical monitors for the Sprint VO2Max study.

The Sprint portion of the 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, while the VO2Max add-on takes a look at changes in aerobic capacity of people working in a closed environment.

While Wiseman worked out, Gerst spent the morning relaxing for science. The German astronaut donned a breathing mask and remained as relaxed as possible to allow for the most precise readings of his oxygen uptake for the ENERGY experiment.

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.

Wiseman rounded out his morning collecting water samples for the Microbiome study, which takes a look at the impact of space travel on the human immune system and an individual's microbiome -- the collective community of microorganisms that are normally present in and on the human body.

Wiseman and Swanson then collected water and surface samples throughout the station to check for signs of microbial contamination. After a one-hour lunch break, Swanson analyzed the water samples.

Wiseman took a break from his work to talk with students in Evansville, Indiana, over the station's ham radio. He then performed a scheduled inspection of the Advanced Resistive Exercise Device, or ARED, before working out on that weightlifting machine.

Next, Wiseman performed some routine maintenance on the Waste and Hygiene Compartment - the station's toilet located in the Tranquility node. He wrapped up his workday charging batteries for a smartphone mapping experiment Swanson will conduct Thursday using one of the station's soccer-ball-sized, free-flying robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES.

Meanwhile, Skvortsov and Artemyev participated in a Soyuz descent training session to review their activities for next week's departure. Their colleague Suraev conducted a photo survey of the panels inside the Zvezda service module.

After Gerst downloaded the data from his ENERGY relaxation session, he spent the remainder of the day working out on the station's exercise bike and ARED to get in his daily exercise quota. Each crew member spends around 2 0.5-hours every day working out to prevent the loss of bone density and muscle mass that occurs during long-duration spaceflight.