Implementation Of Safety And Human-Rating On Lockheed Martin's Crew Exploration Vehicle

Lockheed Martin leads an industry and academic team to develop requirements and the design of NASA's Crew Exploration Vehicle (CEV) in support of the United States' Vision for Space Exploration. This paper discusses the safety and human-rating requirements, challenges, and approaches taken by the team focusing on safety and human-rating design decisions and tradeoffs. Examples of these requirements are failure-tolerance, crew abort/escape, 'design for minimum risk', computer-based control, all reviewed by a new NASA human-rating process. NASA allowed contractors freedom in the approaches they could pursue, which offered the opportunity for safety and human-rating goals to influence the basic concepts and major design decisions made early in the program, which drive the major safety features (and limitations) of the CEV project. The paper discusses the method developed by Lockheed Martin, HazComp, to evaluate hazards of proposed concept options, without the benefit of detailed design data used to provide a hazard-based 'safety figure of merit' and substantiating data to the trade study decision process. The importance of a well-developed preliminary hazard analysis to support these evaluations is discussed. Major NASA safety and human-rating requirements and their evolution are also discussed along with issues, concerns and recommendations for future human space exploration safety requirements and safety focus.