长期太空任务带来了许多挑战，包括提供安全的饮用水 船员用水。从地球上获取水源，用于更远的长期太空任务 近地轨道之所以不实用，有几个原因，包括成本高达 每加仑4万美元。因此，美国国家航空航天局（NASA）已经 专注于开发不需要再补给水的闭环水处理工艺。 在闭环系统中使用和再利用水对环境造成了许多挑战 水消毒，包括“源头”水质差，微生物种群多样， 以及微变异的进化，这可能会导致出现更具抗性的菌株。 为了克服闭环处理系统的障碍，需要一个互补的消毒过程 已被开发用于针对多种微生物。 消毒过程使用 紫外线（UV）辐射作为主要消毒剂，化学消毒剂（碘）作为主要消毒剂 残留消毒剂。紫外线辐射被选为主要消毒剂，因为它是有效的 能够使广泛的微生物失活，并且形成的可能性极小 消毒副产品。碘可以有效地使许多微生物失活，因此被广泛使用 之所以被选为残留消毒剂，是因为它有可能作为在线紫外线双重使用 监视器和消毒剂。此外，自20世纪70年代以来，碘一直被用作NASA太空任务中的水消毒剂。美国宇航局选择碘作为消毒剂，因为它的浓度很低 蒸汽压和相对持久的残留物（Columbo 1987）。包括7个参考文献、图表。

Long-term space missions pose a number of challenges, including provision of safe potable water for the crew. Bringing water from earth sources for long-term space missions beyond near-Earth orbit is not practical for several reasons, including costs on the order of $40,000/gallon. Therefore, the National Aeronautics and Space Administration (NASA) has focused on developing closed-loop water treatment processes, which do not require water resupply. The use and reuse of water in a closed-loop system poses a number of challenges for water disinfection, including poor "source" water quality, diverse microorganism populations, and evolution of microogransisms, which may result in the emergence of more resistant strains. To overcome the hurdles of a close-loop treatment system, a complementary disinfection process has been developed to target a wide range of microorganisms. The disinfection process uses ultraviolet (UV) radiation as the primary disinfectant and a chemical disinfectant (iodine) as the residual disinfectant. UV radiation was selected as the primary disinfectant because it is effective at inactivating a broad spectrum of microorganisms and has minimal potential for the formation of disinfection byproducts. Iodine, which is effective at inactivating many microorganisms, was selected as the residual disinfectant because it has the potential for dual use as an on-line UV monitor and a disinfectant. Also, iodine has been used as a water disinfectant in NASA space missions since the 1970s. NASA chose iodine as the disinfectant of choice because it has a low vapor pressure and a relatively long-lasting residual (Columbo 1987). Includes 7 references, figures.