9 287 8 SPA CRAFf FIRE SAFETY EXPE NTS ci, • • Mechanical, A University of California, Los Angeles FlightE g Monterey, California, October 5-9, 1992 i Sponsored by NASA Lewis Research Center : Sp f fir risk can never be reduced to a zero probabil- ity. t Prob ... ..., ......... essment is a tool to reduce risk to an u acce vel. MAJOR PS· 1. Identifica ·on of "cri ·cal" 1 an a me of e frequency fires: overheating spills 0 smold . ,i 2. ima io 0 he ac· at can Ie to I damag 0 p ci ed component : growth time and the co ing de ction and supp ion time 3. E ima · n e fraction of fires that can lead to 0 mission damage Open Local Ventilation Rack to leak to 4Space U__ nSdyasmteamg ed RTahcrkus P·r opRaagcakIJ i o n f~ Detection Suppression Page 2 ~ 2 ~ 2 '. AretSmoIdertng ~ 2 Incident Closed ~ Space 2 Page 1: E' t Tree for Closed Space Fire '- l! ~ J' t .!oi ~tc I w j Ie ! ~i11 n .. D.. IS en CD C\I • • w ~ c ~ t!: CD CD 0 .. 0 c. CD en 0 " Od/j,k Qoss d/j,k AI freq ey os O freq eyo el ~ . Qd/j fracf on 0 las J s that lead 0 damag of the th criti Qoss d/j,k fraction 0 clas j fire leading to damage of th kth system that cause the loss of the spacecraft = Ij G < H / re T G growth time TH hazard time T f time to de ection T d detector response time Ts suppression time Q .• I fro tI.l ~ ....c =o .' .E / ' - I! I I f D _~- _ _ _ _ J I I I ~.e1..-C .uoC >. .. ;; .. -O - ) ~ UCLA Fire Safety Assessment Target Identification i i I I Damage Time Modes Identification i i Smo Toxins Detection & Suppression Time Event Description - ...... o85 .... c ii -C\i .-6 U g ::s u g .. UCLA I ~fI.... Dama-ge Modes Tests Models Heat Release tempenture measurements f(T) I Source Smoke Release obscuntion, TEM grids f(T) Toxin Release IRlMus spec. (White Sands), sampling f(T) '. Heat Tnnsport • temperature measurements fluid flow, temp., etc S TEM grids/visualization fluid Adjacent Wire Damage pain, bundles heat ..... qualitative D Particulate Deposit TEMg ' 1'8D " pltllt "'tld : .. :.. ........ UCLA NASA Lewis 2.2 sec DroD Tower Sample Materials PTFE - Teflon .. Smoke Production Interior wiring [-CF -CF 2 2-] Toxi Acidic U""'''''I1Ift~"._ ETFE - Tefzel Exterior wiring [-CF - 2 Bundles Interior/Exterior + Adjacent Wire Damage Twisted Pairs Interior/Exterior <i ...... ,