[sarex] STS-115 Astronauts Wrap Up Second Spacewalk

[Arthur Rowe]

SUBMITTED BY ARTHUR N1ORC - AMSAT A/C# 31468

STS-115 Astronauts Wrap Up Second Spacewalk

The second STS-115 spacewalk is now in the history books. STS-115 
Mission Specialists Dan Burbank and Steve MacLean concluded the 
spacewalk at 12:16 p.m. EDT (1616 UTC) after continued efforts to 
prepare the International Space Station’s P3/P4 integrated truss for 
operation.

The 17.5-ton, 45-foot truss, which contains a set of solar arrays, was 
attached to the station Tuesday. The P3/P4 will provide power, data and 
communication services for the station. The arrays will be unfurled to a 
full length of 240 feet Thursday and will eventually double the 
station’s power capabilities.

Burbank and MacLean began their excursion at 5:05 a.m.(0905 UTC) and 
proceeded to move through the scheduled activities, which included the 
removal of launch locks and launch restraints on the Solar Alpha Rotary 
Joint (SARJ). Once activated, the rotary joint will allow the arrays to 
track the sun. It will be tested later today.

About 7:10 a.m. EDT, MacLean reported that one of the four bolts on the 
cover to SARJ launch lock 8 was missing. The bolt had been there when he 
removed the cover to access the lock. MacLean reported he did not see 
the bolt in the SARJ mechanism. The cover is secure with three of the 
four bolts in place.

Later, the socket being used by MacLean to loosen a stubborn bolt on 
launch restraint 6B broke. MacLean retrieved a cheater bar from the tool 
box on the Z1 Truss. He broke the torque, but ultimately it took both he 
and Burbank to remove the bolt and launch restraint.

During the remainder of the spacewalk, the astronauts were instructed to 
perform get-ahead tasks. They prepared of the P3 truss for use by the 
Mobile Transporter – a platform that allows the station’s robotic arm, 
Canadarm2, to move along the Integrated Truss Structure.

Mission Specialist Joe Tanner served as spacewalk coordinator. Mission 
Specialist Heidemarie Stefanyshyn-Piper assisted Tanner and operated 
Canadarm2. Tanner and Piper conducted the first spacewalk and will 
perform the third Friday.