Probabilities of Ground Impact Conditions of the New Horizons Spacecraft and RTG for Near Launch Pad Accidents

As part of the Pluto New Horizons mission’s safety effort, assessment of accidental ground impacts of the spacecraft (SC) and its components, including the radioisotope thermoelectric generator (RTG), near the launch pad are of particular interest as they determine the severity of the mechanical insult to the hardware. Two configurations are studied: the SC with RTG joined to the third stage STAR™ 48B solid rocket motor [Launch Vehicle (LV) payload], and the RTG joined to the RTG mounting fixture but separated from the SC after an at‐altitude destruct action. The objective of the analyses conducted is to determine the probabilities of impact orientation and average impact velocity of these configurations for a near launch pad accident These are of interest because of the possibility that the STAR 48B solid rocket motor could impact on top of the RTG, and because the RTG/RTG mounting fixture impact orientations probabilities and velocities directly affect the mechanical response of the internal GPHS module...