The six-person Expedition 41 crew of the International Space Station was hard at work Wednesday supporting research with down-to-Earth benefits and gearing up for a series of spacewalks to maintain the orbiting laboratory.

Commander Max Suraev and his team of five flight engineers began the day at 2 a.m. EDT, with some time for morning hygiene, breakfast and an inspection of the station. Afterward the entire crew participated in a daily planning conference with the flight control teams around the world to review the day's activities.

For NASA astronauts Reid Wiseman and Barry Wilmore and European Space Agency astronaut Alexander Gerst, the bulk of the day was spent inside the Quest airlock as they resized their U.S. spacesuits for a pair of spacewalks beginning next week.

Having collected measurements of their bodies on Tuesday to compare with baseline measurements taken before launch, the astronauts donned their spacesuits to make sure everything fit properly. These on-orbit fit checks are necessary because astronauts may grow up to 3 percent taller while living aboard the space station.

During the first six-and-a-half-hour spacewalk slated to begin on Tuesday, Oct. 7 around 8:10 a.m. EDT, Wiseman and Gerst will transfer a previously uninstalled pump module from its temporary stowage location to its long-term home on the External Stowage Platform-2.

The two spacewalkers also will install the Mobile Transporter Relay Assembly that adds the capability to provide "keep-alive" power to the Mobile Servicing System when the Mobile Transporter is moving between worksites. Wilmore will be inside the cupola at the controls of the Canadarm2 robotic arm to provide robotic support for the first spacewalk.

Wilmore, who arrived aboard the station late last week along with Russian cosmonauts Alexander Samokutyaev and Elena Serova, will join Wiseman for the second Expedition 41 spacewalk scheduled to begin on Oct. 15 around 8:20 a.m.

The two NASA astronauts will venture out on the station's starboard truss to replace a voltage regulator that failed in mid-May. Although the station has since operated normally on seven of its eight power channels, replacement of the regulator, known as a sequential shunt unit, is considered a high priority.

Wiseman and Gerst also reviewed operating procedures for the U.S. spacesuits' "life jackets," known as the Simplified Aid For EVA Rescue, or SAFER. In the unlikely event that 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. Wilmore will review SAFER on Thursday.

In addition to their spacewalk preparations, the astronauts also supported the science research taking place aboard the station.

Inside the Japanese Kibo laboratory, Wilmore prepared seed samples and a culture dish for the Plant Gravity Sensing experiment, which examines the cellular and molecular mechanisms that enable plants to sense gravity. The researchers behind this study hypothesize that the gravity sensitivity of plants here on Earth can be modified to make crops more resistant to the destructive forces of nature.

Wiseman meanwhile checked in on the Rodent Research experiment, which looks at how living in space affects rodents and how that knowledge might be applied to humans. Wiseman examined the water bag for signs of leakage and made sure the Rodent Research facility's lights were working.

On the Russian side of the complex, Commander Suraev performed an equipment check for the Otklik experiment, which tracks the impacts of particles on the station's exterior. He then gathered data from the Matryoshka radiation-detection study before moving on to stow trash and unneeded items inside the Progress 56 cargo ship attached to the Pirs docking compartment.

The Russian space freighter, which delivered nearly three tons of cargo when it arrived on July 23, will undock from the station in late October for a destructive reentry over the Pacific Ocean.

Samokutyaev meanwhile wrapped up his work with the Aseptik experiment, which is testing methods and equipment for maintaining the sterility of hardware used for biotechnology studies aboard the station. Samokutyaev later transferred cargo out of the Soyuz TMA-14M spacecraft that brought him, Serova and Wilmore to the station last week.

Serova worked with the Kaskad cell cultivation experiment throughout the day, manually mixing test samples within its bioreactor. She also removed the lights and cameras from inside the Soyuz TMA-14M for return to Earth aboard the Soyuz TMA-13M spacecraft when Suraev, Wiseman and Gerst depart in November.

Serova and Samokutyaev also joined Suraev for some routine maintenance work on the Elektron oxygen generator and the life-support system in the Zvezda service module.

While the crew worked inside the station, payload controllers at the Marshall Space Flight Center's Payload Operations Integration Center in Huntsville, Alabama, were uplinking files to the newly installed ISS-Rapid Scatterometer, or RapidScat, to prepare the Earth-monitoring hardware for its initial data collection.

Designed to monitor ocean winds from the station's vantage point, RapidScat is a space-based scatterometer that uses radar pulses reflected from the ocean's surface from different angles to calculate surface wind speed and direction. This information will be useful for weather forecasting and hurricane monitoring.

RapidScat was part of the nearly two-and-a-half tons of cargo delivered to the station by the SpaceX Dragon resupply craft on Sept. 23. Robotics officers at Houston's Mission Control Center remotely commanded Canadarm2 to remove RapidScat from Dragon's trunk and attach it to its adapter on the station's Columbus laboratory on Tuesday.