Commander Scott Horowitz, Pilot Rick Sturckow and Mission Specialists Pat Forrester and Dan Barry, along with Expedition Three Commander Frank Culbertson, Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin, checked out Shuttle systems, navigational tools and docking hardware in advance of Discovery's planned linkup to the ISS.
The docking is scheduled to occur Sunday at 1:38 p.m. Central time over the Indian Ocean northwest of Australia, just south of the Indonesian island of Jawa.
Forrester and Horowitz powered up, unfurled and checked out Discovery's 50-foot long robotic arm, which will be used by Forrester to move the Leonardo cargo module from Discovery's payload bay to the ISS for the transfer of food and supplies, and by Horowitz to transport Barry and Forrester around the Station during their two spacewalks next week.
In addition, Barry and Forrester tested the devices they will use tomorrow to measure Discovery's distance from the ISS and its rate of closure on the complex during the terminal phase of the Shuttle's approach to the Station. Discovery's docking mechanism was also checked out and its outer docking ring extended to ensure it is ready for tomorrow's capture of the ISS docking port on the forward end of the Station's Destiny laboratory module.
Next week, Barry and Forrester will test the spacesuits they will wear during their two excursions outside Discovery to attach a spare cooling reservoir to the ISS and to hook up heating cables for a large truss structure that will be mounted to the Station next year.
The crew enjoyed a few hours of spare time this afternoon to relax as they wound down for the start of an eight-hour sleep period just after 9 p.m. Central time tonight.
Aboard the ISS, Expedition Two Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms spent the day packing up personal items and preparing Station systems for tomorrow's arrival of their replacements, Culbertson, Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin. This was the 156th day in space for the current occupants of the ISS.
The exchange of crew members on the Station will occur on Monday, although formal command of the Station will not be transferred from Usachev to Culbertson until a few hours before Discovery's undocking on August 20.
Almost 7,000 pounds of food, supplies and personal items for the Expedition Three crew are housed in Leonardo, the Italian-built Multi-Purpose Logistics Module (MPLM).
Once the module is transferred to the Station and unpacked, it will be filled with equipment no longer needed on the ISS, including Expedition Two crew clothing and trash for return to Earth.
Discovery is orbiting the Earth in excellent shape with no issues being worked by the flight control team.