American Space Nuclear Electric Systems

ABSTRACT: Since the 1960's the United States of America has launched several space missions using nuclear technology as a mean for propulsion and power supply. The majority of the American nuclear powered spacecrafts were based in radioisotope generators, with the exception of the SNAP-10A (1965), which was the only American reactor ever launched. However, some of the most notorious nuclear reactor based projects developed in the USA in the last four decades were the SPAR/SP-100 (an evolution of the Space Power Advanced Reactor program), the Space Prototype (SP-100), the Prometheus, and the Fission Surface Power (FSP). The latter is still in progress and the others were closed before its completion. This paper describes the main details about each one of these projects with the purpose of serving as a review of the technical history for the major realization steps that were conducted in the USA. This manuscript also approaches the contemporary state-of-the-art, with emphasis to the Demonstration Using Flattop Fission (DUFF) experiment and it's follow-on project, the Kilopower prototype reactor.摘要：自20世纪60年代以来，美利坚合众国已开展多项以核技术作为推进与供能手段的航天任务。美国绝大多数核动力航天器均采用放射性同位素发电机（radioisotope generators）供能，仅有1965年发射的SNAP-10A例外——它是美国有史以来唯一一款发射入轨的核反应堆动力航天器。近四十年来，美国研发的颇具代表性的核反应堆动力航天项目包括SPAR/SP-100（太空动力先进反应堆计划（Space Power Advanced Reactor program）的改进型号）、空间原型机（SP-100）、普罗米修斯（Prometheus）以及裂变表面动力系统（Fission Surface Power, FSP）。其中裂变表面动力系统（FSP）仍处于研发阶段，其余项目均在完成前正式终止。本文详述了上述各项目的核心细节，旨在梳理美国核动力航天领域关键研发历程的技术史脉络。此外，本文还探讨了当前航天核动力领域的前沿技术现状，重点介绍平顶裂变试验（Demonstration Using Flattop Fission, DUFF）及其后续项目——Kilopower原型反应堆。