How Solid Waste Management Works on the International Space Station国际空间站如何处理固体废弃物

Launched in the year 1998 by a consortium of space agencies from the United States， Europe， and Japan， the International Space Station （ISS） was largely assembled in space， a remarkable feat in and of itself. Even more impressive is the fact that the station has been continuously upgraded over the decades since， allowing it to outlive every other space station program in history. The ISS is used for many kinds of experiments， which have in turn transformed our knowledge of astronomy and technology. It’s a testament to the incredible potential of human ingenuity， but that doesn’t mean it’s perfect.

国际空间站于1998年由美国、欧洲和日本的航天机构联合发射。它大部分是在太空装配的，这本身就是一项非凡的成就。更让人赞叹的是，国际空间站几十年来一直在不断升级，这让它成为有史以来运行时间最长的空间站项目。国际空间站用于开展各种各样的实验，这些实验反过来又刷新了我们对天文学和科技的认知。它证明了人类智慧拥有巨大的潜力，但这并不意味着它是完美无缺的。

Everything astronauts eat， and many of the items they use on a daily basis， are destined to become waste. With no landfills or recycling centers to handle all the mess， astronauts on the space station are left with essentially one option： ejecting their garbage into space. Yes， that’s really how they do it， at least for now， but NASA and the other agencies involved with the ISS are searching for new and better solutions.

宇航员的所有食物和许多日常用品都必然成为废弃物。由于没有垃圾填埋场或回收中心来处理所有的垃圾，空间站的宇航员基本上只有一种选择：把他们的垃圾扔进太空。是的，他们确实是这样做的，至少目前是这样。但美国国家航空航天局和国际空间站其他相关机构正在寻找新的优化方案。

A brief history of space trash

太空垃圾简史

During early NASA missions， such as Project Mercury， which put the first American astronaut in space in 1961， waste wasn’t really an issue because the flights were so short. Of the six Mercury missions， only one lasted longer than a day. During these flights， astronauts used bags to collect their waste， including urine and feces， which they could then dispose of upon their return to Earth.

在美国国家航空航天局早期的任务中——比如1961年将第一位美国宇航员送入太空的水星计划——垃圾并不是问题，因为飞行时间非常短。在六个水星计划任务中，只有一个任务持续时间超过一天。在这些飞行中，宇航员用袋子收集垃圾，包括尿液和排泄物，然后可以在返回地球时处理掉。

When Neil Armstrong became the first human to set foot on the Moon， he also dropped off a bag of trash， which included old food wrappers and containers of urine and feces. Subsequent Moon missions took the same approach， and there are now almost 100 bags of trash just sitting on the Moon. Meanwhile， the space agency’s shift in focus from the Moon to the International Space Station prompted an even bigger challenge. The ISS is built to sustain a crew of seven， with as much space as a large house， and there isn’t a convenient place to just ‘drop off’ your garbage.

当尼尔·阿姆斯特朗成为第一个踏上月球的人时，他也扔下了一袋垃圾，其中包括旧的食品包装纸以及装尿液和排泄物的容器。在随后的月球任务中，宇航员们沿用了同样的方法，现在月球上有近100袋垃圾。同时，美国国家航空航天局的工作重心从月球转移到国际空间站，这带来了更大的挑战。国际空间站可以容纳7名工作人员，它的空间相当于一所大房子，里面没有一处方便随手丢垃圾的地方。

How waste disposal currently works on the ISS

目前国际空间站如何进行垃圾处理

To remove waste， the ISS has its own version of garbage trucks. Every few months， small， unmanned craft are sent up to the ISS to deliver the supplies astronauts need to survive in space. After dropping off its shipment， the craft gets loaded up with garbage bags and sent back to Earth. However， you don’t need to worry about astronaut garbage falling out of the sky because the supply craft incinerate when they reenter Earth’s atmosphere. It might come as a shock to learn that the ISS crew disposes of trash by simply burning it up in the atmosphere， but sometimes they don’t even use special craft for it： They just toss it into space.

为了清除垃圾，国际空间站有特制的垃圾车。每隔几个月，小型无人飞船就会被发射到国际空间站，运送宇航员在太空生存所需的物资。飞船卸货后装载垃圾袋返回地球。不过你不必担心宇航员的垃圾会从天空掉下来，因为补给飞船在重返地球大气层时会焚毁。国际空间站的工作人员处理垃圾的方式就是将其送入大气层烧毁，这似乎听起来让人震惊。但有时他们甚至连特殊的飞船都不用：他们干脆把垃圾扔进太空。

Some trash is offloaded during space walks

在太空行走时丢弃垃圾

With the rarity of supply missions and the highly limited space aboard the International Space Station， astronauts don‘t always use unmanned craft for their trash disposal needs. There have been numerous instances in which astronauts have offloaded garbage while conducting spacewalks. A spacewalk is any instance in which an astronaut puts on their spacesuit and steps outside of the ISS. Spacewalks are often done to make repairs on the station， and to upgrade it with new equipment. Spacewalks also allow astronauts to conduct experiments in space， accomplishing things that could never be done in a terrestrial lab. Occasionally， they also serve as trash runs.

由于补给飞行任务非常少，国际空间站的空间又极为有限，宇航员们并不总是使用无人飞船来处理垃圾。在太空行走时丢弃垃圾的情况屡见不鲜。只要是宇航员穿上航天服走出国际空间站的活动都叫太空行走，通常是为了对空间站进行维修，以及更新设备升级换代。太空行走还可以让宇航员在太空开展实验，完成在地面实验室永远无法完成的任务，有时候还顺便扔垃圾。

When astronauts throw trash out during spacewalks， it’s often pieces of old equipment that have exhausted their use or become outdated. For instance， in 2007， the ISS crew tossed out a 1，400-pound tank of ammonia coolant that they had been keeping as a backup for the station’s main cooling system. Once the need for the backup was eliminated， the size of the tank and the hazard presented by ammonia made disposing of the tank the logical choice. In other cases， trash ends up in space by accident， as occurred in 2017， when an ISS crew member lost hold of a debris shield from the station’s exterior.