NASA Adds 3 Days to Space Shuttle Mission

Mission managers decided Sunday to extend Endeavour's mission by three days.

Astronaut Rick Mastracchio holds the failed control moment gyro shortly after its removal from the Z1 truss. Image: NASA TV

(HOUSTON) - Endeavour spacewalkers Dave Williams and Rick Mastracchio are rolling along with the replacement a faulty attitude control device on the International Space Station.

They have removed the faulty device, called a control moment gyro (CMG), from the Z1 truss. The Z1 houses four CMGs that are used to maintain the station orientation in space.

The next step is the installation of the new gyro, which traveled to the station in Space Shuttle Endeavour’s payload bay.

The failed CMG will remain at its temporary stowage location on the station’s exterior before it returns to Earth on a later shuttle mission.

The excursion began 11:32 a.m. EDT.

Mission Specialist Tracy Caldwell is serving as the spacewalk coordinator, and STS-118 Pilot Charles Hobaugh and Expedition 15 Flight Engineer Clay Anderson are operating the station’s robotic arm.

The spacewalk is timelined to wrap up at 6:02 p.m.

Meanwhile, crew members are transferring cargo between Endeavour and the station.

Experts on the ground continue to analyze imagery collected Sunday during the STS-118 crew’s focused inspection of five areas of concern on the Endeavour’s heat shield.

Managers Add Three Days to Shuttle Mission

Mission managers decided Sunday to extend the STS-118 mission by three days.

The decision came after the successful operation of the new Station-to-Shuttle Power Transfer System (SSPTS).

Endeavour is now scheduled to undock from the International Space Station on Aug. 20 and land Aug. 22.

In addition to the extra time at the orbital outpost, managers added a fourth spacewalk that is scheduled to take place Aug. 17.

The SSPTS reroutes power from the space station to the shuttle during docked operations, allowing the orbiter to conserve materials needed to generate power and spend more time in space.