[sarex] Installed New Station CMG

[Arthur Rowe]

SUBMITTED BY ARTHUR N1ORC - AMSAT A/C #31468

*Mastracchio, Williams Install New Station CMG *

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

TO VIEW IMAGE GO 
TO:http://www.nasa.gov/mission_pages/shuttle/main/index.html

STS-118’s second spacewalk is now in the history books. Mission 
Specialists Dave Williams and Rick Mastracchio successfully installed a 
new control moment gyroscope (CMG) onto the International Space 
Station’s Z1 truss during the excursion, which ended at 6 p.m. EDT.

The new CMG replaces a faulty gyroscope, which was removed during the 
first half of the spacewalk. The new gyroscope is one of four CMGs that 
are used to control the station’s attitude in orbit.

Before concluding the 6-hour, 28-minute excursion, the orbital duo 
relocated the faulty CMG to external stowage platform-2, where it will 
stay until it is returned to Earth on a future shuttle mission.

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

The next spacewalk is scheduled to take place Wednesday. Mastracchio and 
Anderson will team up to prepare the station’s Port 6 truss for 
relocation during STS-120. A fourth spacewalk was added to the schedule 
when STS-118 was extended by three days.

In other activities, crew members continued cargo transfers between 
Endeavour and the station. Experts on the ground continued to analyze 
imagery collected Sunday during the STS-118 crew’s focused inspection of 
five areas of concern on the Endeavour’s heat shield.