Effects of uncertainty in hypervelocity impact performance equations and other parameters on variance in spacecraft vulnerability predictions

✍ Scribed by Hilary J. Evans; Joel Williamsen

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 844 KB
• Volume: 23
• Category: Article
• ISSN: 0734-743X
• DOI: 10.1016/s0734-743x(99)00075-5

✦ Synopsis

The increasing man-made debris environment in low-earth orbit (LEO) has prompted NASA to develop new methods for quantifying (and reducing) the risks to spacecraft and crew following hypervelocity penetration by orbital debris. The Manned Spacecraft and Crew Survivability (MSCSurv) computer analysis tool computes the probability of occurrence for seven failure modes which may lead to crew or station loss. The probability of loss, P]o,s, of station or crew (i.e., its vulnerability) due to impact by one or more orbital debris particles is calculated using three major terms: (a) N~p, the number of impacts on the ISS manned modules, (b) Ppo~p, the probability of penetration given that an impact has occurred, and (c) Plo~s/p~n, the probability of loss given that a penetration has occurred. MSCSurv was designed to calculate terms (b) and (c). Utilizing MSCSurv, the objective of this study is: (1) to describe briefly the structure of the Manned Spacecraft and Crew Survivability computer code, (2) to detail results from a Pio,, calculation using baseline penetration, damage, station, and crew-related parameters, and (3) to quantify the variance produced in Ppen/L, npact and P]o.~/po~ associated with each input and modeling parameter used in calculating them. In general, higher uncertainties within Penetration, Damage, Station, or Crew parametric models produced higher uncertainties within the P~o, calculation; however, small variances within some models (such as those for hole size following a penetration) produced larger overall P~o, variance than large variance within other models (such as the crew movement rate, for example).