NASA Space Shuttle Mission STS-101 low temperature applications

Company  Description: (NASA Space Shuttle Mission STS-101 - the primary mission was to deliver critical supplies,  replacements, and spares to the International Space Station, perform a spacewalk and then reboost the station from 230 statute miles to 250 statute miles.

Challenge: Two weeks prior to Shuttle  Atlantis’ launch, a critical hydraulic system component aboard the Shuttle failed a routine test. It was determined that a 320-pound power drive unit (PDU) which controls the Orbiter’s speed brakes and tail rudder was defective and  would require replacement prior to launch. In an effort to prevent a rollback of Atlantis, managers requested the Cryogenics Testbed to devise a method that  would allow the component to be replaced on the Shuttle in a vertical position.

Solution: Cryogenics Testbed decided  to freeze the hydraulic fluid inside the pipe and create “frozen plugs” by wrapping liquid nitrogen cooled tubing around the outside of the titanium lines.  The Cryogenic Testbed built a full-scale model of the hydraulic lines and the concept to freeze  the lines was successfully demonstrated just three days after the initial request. Two days later, the Cryogenic Testbed installed their system on the six titanium lines and started the process to establish and maintain the “frozen plugs” throughout the 30-hour PDU change-out process.

United Space Alliance Crawler Transporter Group - low temperature applications

Company  Description:United Space Alliance is the prime contractor for NASA’s Space Shuttle Program, and is  responsible for the day-to-day operation and management of the U.S. Space Shuttle fleet.

Challenge: The Solid Rocket Motor  Transporter steering cylinder had failed and had to be replaced. The SRM Transporter is used to transfer Solid Rocket Booster segments between the  facilities at the Rotation, Processing and Servicing Facility and the Vehicle Assembly Building.

The steering cylinder is connected by two steel pins. These pins are interference fit and had  been removed from the old cylinder using heat. The use of heat on the new cylinder would have damaged the seals or possibly caused the pin to gall during installation. They needed an alternative solution to install the  pins.

Solution: Cryogenics Testbed  personnel cryogenically cooled the pins to -321 degrees Fahrenheit causing them  to shrink in diameter enough to allow them to be installed without any damage to  the cylinder.