Episode Details

In July of 1969, Neil Armstrong and Buzz Aldrin left the first human footprints on the moon. They also left two pairs of boots, a handful of tools, and four vomit bags. This lunar litter was far from the last space junk humanity has produced. In 2006, Suni Williams lost her camera while tussling with a stuck solar array on the ISS. And the following year, a similar job resulted in the loss of a bag filled with $100,000 worth of tools. These accidental satellites typically have short lifespans, before falling back to Earth and burning up in our atmosphere. However, other pieces of space junk, like SpaceX’s Tesla Roadster, will be stuck in their orbits for the foreseeable future.1969年7月，尼尔·阿姆斯特朗和巴兹·奥尔德林在人类历史上第一次在月球上留下了脚印。他们还留下了两双靴子、一些工具以及四个呕吐袋。这些月球垃圾远不是人类制造的最后一批太空废弃物。2006年，宇航员苏尼·威廉姆斯在国际空间站上处理卡住的太阳能电池板时丢失了她的相机。第二年，一次类似的任务又导致一个装有价值10万美元工具的袋子遗失。这些意外的“人造卫星”通常寿命很短，最终会坠回地球并在大气层中烧毁。然而，像SpaceX的特斯拉跑车这样的太空垃圾，将在可预见的未来长久地被困在轨道上。

In the early days of space travel, this kind of littering was largely considered inconsequential. But in today's crowded skies, orbital debris poses a serious threat to the thousands of satellites that underpin Earth’s vital technologies. Currently, there are over 131 million pieces of debris whipping around the planet at an average speed of 10 kilometers a second. This debris ranges in size from pieces as large as an entire bus, to those as small as a grain of sand. But roughly 1 million pieces are at least one centimeter across, which is large enough to severely damage most satellites. While losing any spacecraft is bad enough, the knock-on effects are even worse. When satellites crash into debris or each other, such as in 2009, when an American communications satellite collided with a defunct Russian satellite, they can explode into thousands of pieces. And if events like these happen often enough, the increase in debris could trigger a catastrophic cascade that researchers have named the Kessler syndrome: a runaway effect which could destroy untold numbers of orbiting spacecraft.在太空探索的早期，这种“乱扔垃圾”的行为被认为无关紧要。但在当今拥挤的太空环境中，轨道碎片对支撑地球重要科技系统的数千颗卫星构成了严重威胁。目前，有超过1.31亿块碎片以平均每秒10公里的速度围绕地球飞行。这些碎片大小不一，从一辆公共汽车那么大到一粒沙子那么小不等。其中大约有100万块直径至少一厘米的碎片，这已经足以严重损坏大多数卫星。失去任何一颗航天器本身已经够糟糕了，但连锁反应更为可怕。当卫星与碎片或彼此相撞时——比如2009年，美国一颗通信卫星与一颗报废的俄罗斯卫星相撞——会产生数千块新的碎片。如果此类事件频繁发生，碎片数量的增加可能引发一种灾难性的连锁反应，即研究人员所谓的“凯斯勒综合症”：一种失控的效应，可能毁灭无数在轨航天器。

But what does all this mean for people on Earth? Well, even if space shrapnel does take down a satellite, most debris burns up during re-entry. So theprobabilityof waking up to a spacecraft in your yard is very small. That said, some large specimens can survive the trip, such as the SpaceXCapsulethat landed in an Australian field in August of 2022. And the odds of something similar happening again grows alongside the amount of space junk. So how can we save our satellites and ourselves from all this trash?那么，这一切对地球上的人意味着什么呢？即使太空碎片击落了一颗卫星，大多数残骸在重返大气层时都会烧毁。所以，你早晨醒来发现院子里掉了一艘飞船的概率非常低。不过，也有一些体积较大的物体能在重返地球时幸存下来，比如2022年8月坠落在澳大利亚农田中的SpaceX飞船舱。而随着太空垃圾数量的增加，这种事情再次发生的几率也在上升。那么，我们该如何拯救卫星和自己免于这片“太空垃圾场”呢？

Part of the solution is to stop creating waste in space, but debris is generated in a lot of ways. In addition to collisions, so