A NASA test at Kennedy Space Center today could help clear the way for the planned launch in early February of shuttle Discovery’s 39th and final flight.More than 500,000 gallons of supercold propellant will be loaded into the shuttle’s 15-story external tank beginning at 7 a.m. as engineers try to determine what caused cracks in structural braces in its aluminum-lithium hull. You can watch live NASA TV coverage here in The Flame Trench starting at 6:45 a.m. Click the NASA TV box on the right to launch our NASA TV viewer.
Almost 90 strain gauges and thermal sensors will record contraction and expansion of tank, as well as temperatures, as it chills and warms during fuel-loading and subsequent draining.
“We don’t expect any results right away,” NASA spokesman Allard Beutel said.
But an extensive analysis of data collected could help pinpoint the cause of four cracks on two 21-foot-long brackets on the ribbed midsection of the tank.
The cracks were detected after a scrubbed Nov. 5 launch attempt. The test also will help verify subsequent repairs to the braces, which are called “stringers.”
The Nov. 5 launch attempt was called off after a significant leak of hazardous hydrogen gas.
Like similar instances that caused launch postponements for two 2009 shuttle missions, the leak was traced to an attachment plate the links a hydrogen vent line to the side of the tank.
The vent line routes excess hydrogen gas to a flare stack a safe distance away from the shuttle.
The test will verify whether repairs have fixed the leak.
Discovery and six astronauts are scheduled to blast off on a supply run to the International Space Station on Feb. 3.
The shuttle will be rolled back to the Vehicle Assembly Building next Wednesday so additional external tank inspections can be performed.
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