Solid rocket booster thermal protection system removal using robotics

Abstract

The Mobile Robotic Hydrolasing System (MRHS) was designed to remove the Thermal Protection System (TPS) from the Space Shuttle's Solid Rocket Boosters (SRB) during disassembly operations at Kennedy Space Center (KSC). The MRHS uses high pressure water (approximately 15,000 psi @ 23 gal/min.) to strip the TPS from the SRB case. This process is called hydrolasing. The system is composed of a 6 4 s articulated robotic arm that incorporates a high pressure water system (straight and rotating tip nozzles and hoses), an electronic controller and its associated instrumentation. All this equipment is mounted on a modified mobile crane cany deck. A series of software programs, executed by the controller, guides the robotic arm along the SRB case and aims the high pressure water in a predetermined stripping path. The Space Shuttle's reusable SRBs are protected with a Thermal Protection System (Instafoam, cork, KSNA-cork and epoxy compound) to avoid hardware damage during flight, splashdown and recovery phases. During disassembly operations at Hangar AF, Cape Canaveral Air Force Station (CCAFS), this TPS must be stripped from the SRBs to be able to demate and refurbish the SRB segments. This operation is accomplished by spraying high pressure water (approximately 15,000 psi G3 23 gal/min.) at the SRB areas where TPS is to be removed. This process is called hydrolasing. Hydrolasing may be performed manually. High pressure water guns are used to strip the TPS from the SRB segments. Trained personnel aim ' Softwardmechanical systems engineer. 2 ~tectrica~ systems engineer. Copylght 8 199.9 by the American Institute of Aeronautiw and Asbonauti*l. Inc. No copyright Is asserted in the United States under Title 17, US. Code. The United States has a royalty-free llmnse lo exerdse all rlghts under the capyrlght claimed herein for Governmental purposes. All other rights are reserved by the oopvrlqht owner. 'CJ these guns at the SRB areas to be cleaned. Manual hydrolasing poses a safety hazard to the operator due to the high pressure water used in the process as well as the exposure to flying TPS debris from the stripping operation. During hydrolasing operations, the operator must wear a special protective suit, which is purged with breathing air. He has to strap the hydrolasing gun to his shoulder to be able to control the direction of water flow with his body. Due to the high pressure of the water, the operator effort required to constantly control the gun is large. This operation has the potential of producing muscle and nerve damage to the operator's shoulder and arm. Manual hydrolasing operation is hazardous due to the potential risk of personnel injury by the high pressure water. Furthermore, it is a source of fatigue to the operator because of the amount of effort required to aim and maintain the hydrolasing gun pointing at the SRB case.