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Abstract-Traditional requirements specification and hazard analysis techniques have not kept pace with the increasing complexity and constraints of modern space systems development. These techniques are incomplete and often consider safety late in the development cycle when the most significant design decisions have already been made. The lack of an integrated approach to perform safety-driven system development from the beginning of the system lifecycle hinders the ability to create safe space systems on time and within budget. To address this need, the authors have created an integrated methodology for safety-driven system development that combines four state-of-the-art techniques: 1) Intent Specification, a framework for organizing system development and operational information in a hierarchical structure; 2) the STAMP model of accident causation, a system-theoretic framework upon which to base more powerful safety engineering techniques; 3) STAMPbased Hazard Analysis (STPA); and 4) State Analysis, a model-based systems engineering approach. The iterative approach specified in the methodology employs State Analysis in the modeling of system behavior. STPA is used to identify system hazards and the constraints that must be enforced to mitigate these hazards.Finally, Intent Specification is used to document traceability of behavioral requirements and subject them to formal analysis using the SpecTRM-RL software package. In this paper, 1,2 the application of this methodology is demonstrated through the specification of a spacecraft high gain antenna pointing mechanism for a hypothetical outer planet exploration mission.

The concept of imaging spectrometry is finding broad application in scientific instrumentation for Earth-based, airborne, and space applications. An imaging spectrometer is characterized by the combination of imaging with complete sampling in the spectral domain. In so doing, material identification can be accomplished and displayed in conjunction with the conventional recognizable image.An imaging spectrometer incorporates a wide variety of technologies, including focal plane arrays, imaging and spectrometer optics, and spectral dispersing devices. The design of a successful system involves a complex set of trade-offs incorporating the properties and limitations of the various technologies. For applications in the infrared, additional technologies such as focal plane cooling are required, and the other technologies present more limitations and constraints. This paper will describe the system design process for a typical application, and will discuss the system performance parameters and trade-offs, including choice of system architecture, signal to noise ratio, system resolution, spectral performance, calibration, and the effect of artifacts such as detector non-uniformity.