The aerospace launch probability simulation

Launch timeliness is an important consideration for mission modeling and optimization. This is especially true for planetary missions and may well be of critical importance for future crew rescue missions. The Aerospace Launch Probability Simulation (ALPS) is a discrete event simulation based tool that produces a cumulative probability distribution estimate for when a space launch is likely to occur relative to the planned launch date at the start of the launch countdown. ALPS considers all factors that have the potential to scrub a launch attempt including problems with the launch vehicle, the payload, which could be a crewed space capsule, and supporting launch range infrastructure as well as the weather constraints. The model can be run with all scrub factors active or with any combination of factors enabled or disabled. Historical data from all Space Shuttle, Atlas V, Delta IV and Falcon 9 launch attempts was analyzed to develop estimates for the scrub factors in terms of their probability of occurrence and the duration of the associated scrub. ALPS can analyze Atlas V, Delta IV, and Falcon 9 launch probabilities in its current state of development. This paper describes all of the scrub risk factors, their basis of estimate, and presents comparative cumulative probability distributions for Atlas V, Delta IV, and Falcon 9. ALPS can be used to ensure mission success when launch timeliness is critical.