Evolution of the space nuclear launch safety review process

Space nuclear power—and in particular radioisotope power systems (RPSs)—serve a niche class of deep space missions: Long-duration missions that travel to areas where solar flux is too low or where the environmental conditions are too harsh for solar power to provide sufficient power levels. When certain missions do not have a nuclear power option available, science objectives get re-scoped, transmission of data back to earth is often slower, and the overall return on investment may be compromised. Yet in the past 15 years, the United States has launched historically fewer RPSs. Among other challenges, users of RPSs face a lengthy and costly launch certification review process unlike safety review processes for other aspects of launch. In order to better understand the RPS launch certification process, this paper traces the evolution of the legal, regulatory, policy frameworks that drives RPS certification via literature review and expert interviews. Documents reviewed include the Presidential Directive/National Security Council Memorandum 25, among others. To the extent possible, we consider the original intent of the document, the effect of the document on the system initially, and its current impact on the system. With an historic context of legal, regulatory and policy documents, we examine how the implementation of the process has evolved and in what ways. We look at reasons for change in the process, how those changes compare to the language of pertinent legal and policy documents, how, if it all, the changes affected the missions, and what, if any, value-added was brought on by the changes. We then consider potential ways forward including: Laws, regulations, and policy pieces that can be clarified or changed in order to better support the system or ways to clarify best practices to foster a more efficient but equally robust system.