Human Space Flight Mishaps and Incidents: An Overview

Abstract

This chapter is an overview of human spaceflight-associated mishaps and incidents and also describes human health threats involved with spaceflight. Humans flying is space have historically had a higher risk compared to comparable humans engaged in aviation operations, particularly fatal mishaps (loss of crew) per mission sortie (launch/landing). Historical loss rates in suborbital winged reentry vehicles (X-15) is approximately 1 in 100 sorties, and in orbital flight, both blunt capsule (Soyuz) and winged vehicles (Space Shuttle) was approximately 1 in 70 sorties, while civilian general aviation fatal mishaps are 1 in 100,000 sorties, while in regulated airline flights the fatal rate is approximately 1 in 10 million sorties. Fatal space mishaps historically have occurred during high energy transition states (launch/ascent) where chemical energy is converted to kinetic (airspeed) and potential energy (altitude), as well as reentry/landing where potential (altitude) and kinetic (airspeed) are converted to thermal energy (reentry heating). All phases of flight from launch, ascent, on-orbit, and reentry and landing and post-landing all have risk associated with them. As risk is quantified by consequence (outcome) times duration, the on-orbit portion, being longer than the launch and reentry period, is also of concern, as even minor conditions can worsen over time. Specific risks include the space environment, such as radiation, the vehicle environment, and the mission architecture. For commercial space operations, informed consent is a mandatory requirement for spaceflight participants to recognize and understand.