This document presents a status update of the design and integration of a throttled launch assist hybrid rocket motor for an airborne nano-launch platform. Currently, NASA Armstrong Flight Research Center (AFRC) is developing a scaled prototype of a high lift-to-drag (L/D) ratio glider designed as a flexible low earth orbit (LEO) launch platform for nano-scale satellites (NanoSats). Because the high L/D platform is delivered to the launch altitude and airspeed using a high-efficiency air-breathing propulsion system, there is a significant reduction in the required ΔV that must be delivered by the launch vehicle. Optimal ΔV savings are achieved when the NanoSat launch vehicle is delivered to a high-flight path angle that will approximate the condition that would be achieved along a ground launch trajectory at the same altitude and airspeed. The glider platform itself is unable to achieve this flight condition, and launch assist propulsion is required. A hybrid system was selected for the launch assist motor because of the inherent safety, operational simplicity, and environmental friendliness of the propellants; and because of the ability for the hybrid system to be throttled and re-started on demand. This study establishes the requirements for this launch assist propulsion system, develops the system design features, and presents the end-to-end hardware layout. System performance requirements are verified by integrating a simplified, medium fidelity throttled rocket system model into a 6-degree of freedom high-fidelity vehicle simulation. The medium fidelity simulation is derived from a high fidelity hybrid rocket ballistic model. The system design establishes appropriate factors of safety and identifies specific components to be installed on the final test configuration.
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