Endeavour Power Box Testing Continues, New Launch Date Expected Friday

"Thu, 05 May 2011 17:37:22 -0500"

Technicians at NASA Kennedy Space Center's Launch Pad 39A in Florida
continue testing various systems inside space shuttle Endeavour
associated with a newly installed power distribution box, called a
Load Control Assembly 2 (LCA-2). So far, all systems have checked out.
Overnight, teams will retest power for Endeavour's reaction control
system. Endeavour's no earlier than launch date remains May 10, but
senior NASA managers will meet Friday to evaluate the progress of
repairs and select a new
launch date for the STS-134 mission to the International Space
Station. Engineers have been doing forensic engineering testing on the
failed LCA-2, which was removed from Endeavour on Tuesday. The LCA-2
feeds power to a variety of systems, including heaters on the fuel
line for Endeavour's auxiliary power unit-1 (APU-1). APUs control the
shuttle's hydraulic system. Teams are trying to determine what caused
a circuit inside the power box to short out. The APU-1 fuel line
heaters did not work on
April 29, prompting the launch team to scrub Endeavour's first launch attempt.