This paper re-evaluates the concept of disposing of high-level nuclear waste (HLW) by launching it into outer space. While historical studies by NASA and others concluded space disposal was technically feasible, they identified two insurmountable barriers: catastrophic launch failure risk and restrictions imposed by the 1967 Outer Space Treaty. This analysis examines whether modern reusable launch systems have altered this result. Despite a dramatic reduction in launch costs, this paper argues that safety and legal impediments remain unresolved. However, under high-growth nuclear energy scenarios, cumulative HLW could triple by 2070, exceeding the capacity of all planned geological repositories. This growing waste inventory creates renewed pressure to reconsider space-based options within a 20-50 year timeframe. The paper details two disposal trajectories of interstellar ejection and a direct solar impact, provides original modeling, analyzes barriers, and proposes a path forward with specific timelines, costs, and a decision threshold. The paper concludes that space disposal is not a viable option today but may become a necessary and feasible solution in the latter half of the century if launch reliability reaches 99.99% and international legal frameworks are amended accordingly.
Che et al. (Sat,) studied this question.