A Gliding Vehicle for ISS Crew Rescue - Mission Operational Concept

Abstract

The purpose of this preliminary study is to analyse important operational aspects of using a generic gliding vehicle for ISS Crew Rescue Missions. In particular, mission duration, coast and re-entry windows, ground coverage and maximum loads are investigated. A fourstep approach is followed: first, re-entry corridor is computed taking into account thermomechanical constraints; second, the descent trajectory is simulated down to an altitude of 25 km, where the Terminal Area Energy Management (TAEM) guidance switches on. Third, footprint is computed for every point along the ISS orbit with a computationally-efficient approach to easily define both available re-entry windows and coast phases. Fourth, ground network coverage is analysed for a family of possible trajectories. The results of this preliminary analysis show that, considering a single target airport in Europe, the maximum coasting between two consecutive windows lasts about 6 hours. Moreover, it is demonstrated that the coast duration can be halved by adding an extra-runway in the Indian Ocean. Concerning ground coverage, it is shown that using a conventional network of stations does not provide sufficient link. Therefore, a satellite data relay system, like the American TDRSS, is highly recommended. Apart from number and comfort of the seats (important in case of injured astronauts), the short coasting duration, the possibility of landing on a runway and the low accelerations at re-entry are the main strengths of a gliding vehicle compared to a Soyuz-like capsule. I. Nomenclature= Earth oblateness r = geocentric radius t = time * Mission Analysis Engineer, Systems Engineering Department at AVIO Spa on behalf of AizoOn Consulting, strada del Lionetto, Turin, giuseppe.dicampli@aizoon.it.