AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin Kirk Akaydin Week 5: Feb. 15 th, 2007 Project Manager Cost/Schedule/Risk Analysis This Week: Risk Assessment

AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin Crewed Mission Phases / Risk Intro 1) Earth launch 2) Rendezvous 1 & dE 3) Earth-Mars transit 4) Mars arrival –A. Parking orbit –B. Surface landing 5) Mars operations –A. Orbit operations –B. Surface operations 6) Mars launch –A. [N/A] –B. MT launch 7) Rendezvous 2 & dM –A. SR rendezvous –B. Crewed transfer 8) Mars-Earth transit 9) Earth arrival Break phases into specific events –Mission A: 26 major events –Mission B: 38 major events Assess risk at each event –Probability of failure, P(fail) –Probability of fatality given a failure, P(fatal) –Reliability of mitigation strategies, P(mitigation) Multiple failure modes –Navigation/avionics failure –Propulsion system failure –Structural failure –Etc… Risk from each failure mode: –P i (loss) = 1 – P i (fail) P i (fatal)(1 – P i (mitigation)) Risk for major event: –P(survive) = 1 - product(P i ) 9 PhasesRisk Estimation

AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin Probability of killing the crew by Phase PhaseMission A (crew 1)Mission B (crews 2-9)Δ (%)Δ (from 1) 1) Earth launch99.85% 0.0%0 2) Rendezvous 1 & dE99.89% 0.0%0 3) Earth-Mars transit99.74% 0.0%0 4) Mars arrival99.99%97.88%2.1%200 5) Mars Operations99.75%99.69%0.1%1.24 6) Mars launch(100%)99.70%0.3% ∞ 7) Rendezvous 2 & dM99.79%99.76%0.03%1.14 8) Mars-Earth transit99.83% 0.0%0 9) Earth arrival98.97% 0.0%0 Entire Mission97.80%95.4%2.40%2.09 Note: 66% Probability of all 9 crews surviving

AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin End of Presentation

AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin Probability Basics Define –P(A) = probability that event A will occur Example: Earth Launch –P(fail) = 1% (probability that the launch vehicle will fail) –P(fatal) = 99% (probability that the launch vehicle failure would kill the crew) –P(escape) = 85% (probability that the escape tower will function properly in the event of a launch vehicle failure) Computing probability combinations –P(crew dies) = 1 – P(fail)*P(fatal)*(1 – P(escape)) –P(crew dies) = *0.99*(1-0.85) = % Probability of nominal mission (no failures) –P(nominal) = 1 – P(fail) = 99.0%

AAE450 Senior Spacecraft Design Project Aquarius Kirk Akaydin Risk Reliability Trade Study: Quantity vs. Quality Mass/unit500kg $/kg to Launch $ 10,000.00FY2007 Reliability/unit Number12345 Reliability99.80%99.84%99.83%99.81%99.83% Cost/unit $16,666, $ 2,828, $ 969, $ 540, $ 396, Build Cost $16,666, $ 5,656, $ 2,907, $ 2,162, $ 1,980, Launch Cost $ 5,000, $10,000, $15,000, $20,000, $25,000, Total Cost $21,666, $15,656, $17,907, $22,162, $26,980, Normalized100.0%72.3%82.7%102.3%124.5%