Space Shuttle Atlantis Gets Help From ACCU-FREEZE
The space shuttle Atlantis was on the launch pad ready to go on mission ST-101. A last minute systems check revealed a fault in the Power Drive Unit (PDU, see attached news story Florida Today April 11,00). The PDU is a hydraulic power pump which controls the shuttles’ rear rudder or air brake. A failure of this unit during flight could have catastrophic consequences. Repairing this sensitive system meant scrubbing the launch and rolling the shuttle back to the Vehicle Assembly Building and draining out the hydraulic lines to replace the PDU. This would delay the launch for weeks and cost untold dollars. An engineer from United Space Alliance then came up with the idea of freezing the hydraulic lines feeding the PDU while the shuttle was still in the launch position. This would enable the repairs to be made without draining out the entire system and in turn keeping the launch on schedule. Now the question was how ? This kind of repair had never been attempted by shuttle engineers.
Shuttle engineers hit the “web” and to their luck found COB Industries Inc. in Melbourne Florida, only an hour away. COB has been manufacturing pipe freezing systems for industry for over 25 years for customers in the plumbing, nuclear and fossil power generation, nuclear propulsion, municipal water, and many other piping industries.
The job was to freeze six 5/8″ hydraulic fluid lines. These lines were nested in the base of the tail of the shuttle and access was at a minimum. The hydraulic fluid was known to have a freeze point of approximately -150deg. F.
The COB “ACCU-FREEZE” system was chosen as the only viable choice. This system utilizes a digital controller to regulate the flow of liquid nitrogen to perform pipe freezes on 3/8″-12″ ID pipe. Shuttle engineers needed to be able to monitor and control the temperature of their pipes in order to ensure that the freeze was being safely and consistently controlled. The patented “ACCU-FREEZE” system is the only system in the world that meets this criteria.
Three days of testing commenced. Shuttle engineers and management needed to be sure that this new concept would work. After multiple successful freezes in front of shuttle management the engineers and COB were given the green light. On Wednesday April 12th on site and in drenching rain the six hydraulic lines to the shuttle PDU were frozen simultaneously. Due to the inclement weather the replacement had to be delayed, this required the freeze to be held for over 24 hrs. The “ACCU-FREEZE” system performed without a hitch. On Thursday, April 13th the PDU was replaced with a spare from the space shuttle Columbia. Never before had the shuttle program performed an emergency repair of this nature on the launch pad.
If you would like more information please contact Cletus O’Brien at (321) 723-3200 or email to sales@cob-industries.com
