A Suite of Analyses and Tools Used to Lower Risk and Maximize Mission Success of Space Systems

In every design demanding a low-risk of anomalies, reliability analysis can add substantial value in the verification of project and design requirements. This is especially difficult when the mission environments are extreme, the hardware is predominately unserviceable and some critical phases of its mission require autonomous operation. At the Jet Propulsion Laboratory (JPL) reliability analyses play a critical role in the prevention of post-launch anomalies which could be mission limiting or ending before mission objectives are achieved. Through a combination of robust design requirements, heritage design, past project experience, and reliability analysis requirements, JPL strives to create and implement missions with low-risk profiles. The end result is a tailored set of design and test requirements supported by a robust reliability analysis program which, when properly implemented, helps ensure the execution of low-risk missions.Part of an effective reliability analysis program is through a documentation and communication process, detailing design discrepancies and communicating risk to the project.This paper will outline some important elements of a robust reliability analysis process, similar to what is used at JPL, which, when implemented properly, helps lower risk and maximize the probability of success, especially for missions with long duration in harsh environments. Looking back at past space missions, in-flight anomalies have occurred which could have been avoided by performing reliability analyses that were omitted. Still there remains an ongoing debate between the need for reliability analyses or if analyses can be omitted without significant risk being introduced. Due to an increase in the opportunities for space-based science research and an increase in players competing for those interesting projects, there is corresponding pressure to decrease budgets and compress schedules. With an increase of budgetary pressures for limited development funding, there has been a tendency to classify complex missions lower which commensurately reduces or eliminates some of the reliability analysis requirements. With the pressure to reduce the scope of or eliminate certain analysis requirements, understanding the benefits of each analysis type becomes increasingly important. As a result, hard choices often need to be made regarding which analyses offer the most value and which can be omitted without substantially adding to the risk profile. When we have budgetary limitations, which preclude our ability to perform a desired minimum analysis set, then we must find ways to do more with less. One way to accomplish this is the development of tools and methods to allow analyses to be performed faster without sacrificing accuracy or the results that can be gleaned from them. Creating such tools and processes in not the subject of this paper.The remainder of this paper will be focused on the valuable risk information that is provided by each analysis type, important aspects of documenting and communicating project risk, and the optimal timing and frequency in which the analyses should be performed to be able to effectively communicate project risk in budget constrained projects.