Range safety requirements and methods for sounding rocket launches

This article describes requirements and methods employed to ensure safety during sounding rocket launches. Sounding rockets are typically rail launched on suborbital trajectories with no active guidance systems; instead fins are used to stabilize the rocket by moving the center of pressure behind the center of gravity. Fins mounted at an angle to induce spin about the roll axis are a particularly effective means to maintain flight along the intended trajectory. This article reports on the application of high fidelity trajectory and debris impact dispersion analysis methods and launcher setting optimization techniques to prevent debris impacts outside of the pre-determined hazard areas for multi-stage spin-stabilized sounding rockets. Accurate trajectory analyses, for nominal and malfunction conditions, are critical to the safety of sounding rocket launches, whether or not a risk assessment is performed. Therefore, a significant section of this article addresses requirements and methods for high fidelity trajectory analyses, including lessons learned from recent experiences. Examples are presented to demonstrate that a full 6DOF trajectory analysis is necessary to compute accurate impact dispersions for sounding rockets with significant angular momentum. The importance of angular momentum to the flight dynamics of a typical spin stabilized rocket highlights the desirability of a nominal impact dispersion analysis that uses the Monte Carlo technique to account for the non-linear effects of various combinations of input parameter perturbations, such as launch elevation and thrust angle, or thrust offset and thrust angle. This article also describes requirements and methods used for public risk management of sounding rockets, including risks to people in various transportation modes such as aircraft, ships, and automobiles. This article assesses generic types of sounding rocket anomalies, such as fin failures, motor case ruptures, or staging anomalies, and illustrates methods to address these types of events from a range safety perspective.