An Integrated Approach to Verification and Validation of NASA’s Dragonfly Mission

Verification and Validation (V&V) of complex space systems is critical and challenging on even the most straightforward missions, and Dragonfly’s ambitious goal of conducting science measurements enabled by rotorcraft flight on Titan, Saturn’s largest moon, increases the complexity of V&V planning. Due to the physical constraints we have on Earth, it is impractical and sometimes impossible to conduct verification of space systems in a “Test as You Fly” manner. This means we must rely heavily on analyses and modeling where testing is not sufficient. It also places a large emphasis on determining a comprehensive list of the tests that can be conducted on Earth in a flight-like manner.The process we have implemented shifts V&V planning to begin earlier in the design lifecycle. This process also includes involving subject matter experts in Integration and Test (I&T) and Test Environments in the initial planning. The V&V Core Team is made up of the Requirements Lead, Verification Lead, Test Environments Engineer, and I&T Lead. With the aid of the Test Environments Engineer and the I&T Lead, we have identified test configurations achievable and specified the test environment requirements necessary to provide confidence that the tests being planned can realistically be conducted.Involving the Test Environments Engineer and I&T Lead in the verification planning process prior to the Preliminary Design Review enables higher fidelity I&T planning early in the mission development process. It also allows for a detailed understanding of the logistics that feed the I&T campaign since each test configuration was assigned to multiple system-level test locations across the United States.The verification planning effort culminated in the creation of verification planned events, which were incorporated into DOORS not only as an attribute in a requirement, but through the use of integrated Verification Events Modules (VEMs). We were able to provide a single source of truth for all verification events that will occur at the System and Element level. These VEMs provide a common link between requirements and all of their verification events, allowing for detailed planning and inclusion of verification planning notes and success criteria. Verification owners can then easily access these notes while creating their individual test plans and procedures, minimizing the risk of gaps in the verification of the system.