What Engineers Do… 1

Engineers 2

3 Energy Absorption

Impetus for project – Rocket and Crew Capsule separation events (reduce mass, deploy parachutes, …) Video - CST Video – SpaceX Pad Abort (16:00 pad abort) Video – Pyrotechnics & Delta4 (1:16 ground test, 5:32 delta4 sep) – Some separation events require bolt capture and impact reduction to protect vehicle, reduce ‘shock’ to electronic components. One approach to impact reduction is to remove energy (crushable material, damping) of projectile prior to impact Space Shuttle bolt catcher (next slide) 4

Energy Absorption – Shuttle Bolt Catcher 5 The ET and SRB were held together by the forward separation bolt until the separation command was given by the Orbiter Pyrotechnic charges were fired at each end of the bolt The bolt was internally loaded by the pyrotechnic charges until the bolt broke The head and nut ends were accelerated to around 75 to 80 fps (80 fps = 55 mph) Each bolt half weighed about 35 pounds The head end was stopped by the bolt catcher The nut end was stopped by the energy absorber in the SRB thrust post Final Honeycomb Design