Dec 16 2010
The space shuttle Discovery's exterior tank will be subjected to a tanking examination by the experts at NASA. A total of 89 sensors will be integrated in the spacecraft for collecting varied data.
The strain gauges mounted on the tank will accurately log the motion and thermal data from the ribbed intertank area of the tank, when it is cooled and heated recurrently during the fuel filling and emptying process. The tank is filled with highly chilled liquid oxygen with an extremely low temperature of -2970C and liquid hydrogen having -4230C. These cryogenic propellants minimize the tank size by about half an inch.
This tank test will facilitate the validation of repairs related to cracks along the tops of the dual 21-foot-long, U-modeled aluminum brackets, called stringers, on the exterior of the tank and will aid detecting the root cause of the cracks. The experts had already removed the cracks and fixed foam insulation on the stringers earlier.
It was found that more inspections and validations were required before the STS-133 mission’s launch of the Discovery to the International Space Station.
Source: http://www.nasa.gov