This paper deals with selection and analysis of two-stage endo-atmospheric separation of supersonic parachute of a test projectile. Flight scenario reads that after the motor burns out, it is separated from the projectile, a few moments after which the parachute is ejected out of the payload and set in the open mode. It is important to study the modes of the stages involved and set a safe distance between them. As this process involves some random variables and needs more time, a shortcut statistical method has been employed in uncertainty variables functions to carry out the analysis. It is meant to take appropriate measures in order for the separation to be collision-free and safe. To do so, relative position of the two stages are modelled and simulated. A statistical method is employed to analyse the relative distance between the two stages in critical points. The results reflect that a safe distance is maintained in the stage of parachute deployment and after supersonic parachute is employed. In addition the said analysis is also carried out via Monte Carlo method. Comparison of the results of these two methods is indicative of a small error. The statistical method is validated and sufficient knowledge on relative attitudes of the stages is obtained.

Unlike conventional ballistic parachutes, gliding parachutes have been extensively used as guided precision aerial delivery system (GPADS) platforms in recent years. The reasoning may be found in gliding and manoeuvering capabilities, which make this kind of ram-air parachutes superior for precision aerial delivery application. In contrast, wing-shaped configuration along with more design variables create a cumbersome design procedure for this type of parachute. Especially, when an affordable configuration is demanded, the design procedure will be a more important problem. In this respect, an innovative integrated design framework is proposed in which significant design aspects are considered so that the gliding parachute configuration can be optimiseoptimised through a bi-objective optimisation problem to find optimum cost for achievable gliding ranges. To do so, the configuration is defined with minimum required parameters and design space is constrained by performance and stability as significant design requirements to guarantee the feasibility of the solutions in practice. The objective functions are defined in terms of gliding characteristics and amount of materials for fabrication which are representative for maximum reachable stand-off distance and unit cost, respectively. As an effective numerical optimisation method, a niched multi-objective genetic algorithm (MOGA) is used to generate a pareto-optimal set for a specific payload mass whereas constraints are handled through a tournament selection process. Based on results, the provided pareto front can aid the designers in decision-making and trade-off between demanded objectives for a payload weight. The underlying design problem is solved using an all-at-once (AAO) approach and the design loop converges to favourable results in a reasonable time. Finally, as a comparative study, an optimiseoptimised affordable cargo parachute is proposed for the GPADS application in which the material cost is reduced by at least 25% with respect to an available low-cost gliding parachute with the same glide ratio.

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