Performance Evaluation of Bolt-Cutter System on First Taurus Launch.
AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS
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In rapid response to the request of the Space Test and Experimentation Directorate in Space Launch Operations, a launch-critical experimental investigation was conducted to evaluate the performance of a particular bolt-cutter system for separating stages on the first Taurus launch. The tests were to examine the variation of tension preloading on the bolt system and to demonstrate the tolerable margin on this parameter for such launches with the new types of bolts since the preloading was known to vary as much as 12 from a preset value before launch. We planned and carried out the experiment, designed and assembled the fixture to properly simulate flight application, and developed diagnostics. Four bolt cutters were purchased from the manufacturer for these tests, and one was provided by the contractor. In addition to the obvious requirement to demonstrate the successful severing of bolts under varying preloads, ignition-wire current and timing of chisel impact on the bolt were monitored. An optical diagnostic was designed to determine the flyout velocity and kinetic energy of the broken pieces. These latter measurements will be useful in anchoring performance codes simulating and assessing the structural dynamics of the bolt-cutter function for future missions. The tests were conducted successfully and the bolts were severed successfully in all five tests. The preloads were successively lowered from 2,500 lb to 2,250, 2,000, 1,500, and 1,000 lb These tests contributed in a timely manner to the STEP launch decision and to launch mission assurance. They demonstrated important margin to the nominally set 3,200 lb. preload. The entire complicated experimental program from inception to completion was accomplished in less than three weeks.