The crews of Discovery and the International Space Station spent Tuesday unloading more of the 7,000 pounds of clothing, food and other supplies brought by the shuttle in the Italian-built multi-purpose Leonardo cargo module.
After Leonardo is unloaded, the nine crew members then will remove more than 4,300 pounds of experiment results, unneeded hardware and trash from the station and place it into the pressurized container for transport back to Earth when the shuttle undocks from the orbiting facility next week.
Mission specialist Stephanie Wilson is serving as loadmaster for the material transfer efforts.
Shuttle astronauts Mike Fossum and Piers Sellers prepared for their third and final spacewalk, which is scheduled for Wednesday. Among other tasks, they recharged their spacesuits, gathered and organized necessary tools and checked the configuration of the airlock for their exit.
Discovery's commander Steve Lindsey, its pilot Mark Kelly, and fellow mission specialists Lisa Nowak and Wilson also reviewed the next spacewalk's procedures.
The only other scheduled event of the day involved Kelly, Fossum, Nowak, Wilson and Sellers talking with reporters for 20 minutes Tuesday morning.
Wednesday's spacewalk, which will test on-orbit shuttle heat-shield repair techniques, is scheduled to begin at 7:13 a.m. Eastern Time.
Even though NASA engineers have cleared Discovery of any damage that could prevent it from returning home safely, the astronauts will make one more inspection of their craft before attempting to re-enter the atmosphere to make sure it has not been damaged by orbiting debris or even micrometeorites.