Verification & Validation by Risk Class: Understanding how Risk Classes affect the V&V process

There is an oft quoted saying in the space industry, “Every mission is Class A on the Launch Pad”. No matter the stated risk class of your mission, when it is time to launch, the mission must be a success. In this paper we will discuss the accuracy of this statement, and explore the strategic and tactical approaches to the Verification and Validation of four missions with distinct Risk Classifications: the Mars Science Laboratory, the Dawn mission, the Orbiting Carbon Observatory-2 (OCO-2), & the Terrain Relative Navigation and Employee Development (TRaiNED) projects. Each mission exemplifies one of the four specific risk classes of NASA (National Aeronautics and Space Administration) missions. At one extreme, the Mars Science Laboratory mission (Risk Class A), required extensive Verification and Validation, consisting of traditional Mission Systems Operational Readiness Tests (ORTs), Entry Descent and Landing (EDL), and the uncharted territory of sample handling verification on the surface of Mars. The Dawn mission (Risk Class B), designed to travel to two separate bodies in the Asteroid belt, and focused its V&V efforts primarily on the validation of the spacecraft. This emphasis allowed the team to weed out the difficulties inherent in a complex system, providing the project-level focus necessary to resolve system-wide issues. OCO-2 mission (Risk Class C), designed to measure carbon dioxide in earth’s atmosphere, took a different tack. It centered on the verification process and successfully adopted several lessons learned from its predecessor, the OCO mission. In particular, it has implemented more efficient ways of tracking requirements such as scheduling burn down plans based on verification milestones, rather than on precise dates. Finally, the TRaiNED mission (Risk Class D), a small sounding rocket mission designed to collect data to validate several Terrain Relative Navigation (TRN) models, had to compress its Verification and Validation process into a much more condensed timeframe. To maintain this tight schedule, the team tailored the V&V plan to emphasize only the processes absolutely necessary in order to meet the systems requirements. For each of these missions, we will examine both the overarching Verification and Validation processes applied, along with some specific examples of how these processes were implemented in order to bring the mission successfully through its integration and test phase. In the process of examining these missions, we will highlight the factors that separate each mission by classification and the effect classification has on mission decision-making.