NASA-LLIS-0143

Abstract

<strong>Description of Driving Event:</strong> <br>The ESP and ECP are designed to support maintenance and replacement of space shuttle main engines (SSME's) while the orbiter is in a vertical position. Both platforms utilize the same hoisting system, located on level B of the mobile launch platform (MLP). A combination of four hoists raise and lower the platforms through the SSME exhaust hole. The platforms are secured to the MLP prior to SSME maintenance/installation. A design certification review was performed on the platforms. The review identified three non-compliances to design standards as givin by KSC-STD-Z-0002B, standard for design requirments for lifting and hoisting equipment. These are (1) no emergency stop switch, (2) no final upper limit switch, and (3) only one holding brake. However, the upper limit switch was shown to be impractical due to varying heights of the platforms, proximity of the platforms to the tail service mast, and independent operation of the winches. A failure in the hoisting system during raising/lowering could cause the platform to tip, resulting in damage/loss of a SSME, ground support equipment, or MLP.