The weirdest stuff orbiting Earth

[00:00.69] In July of 1969, Neil Armstrong and Buzz Aldrin left the first human footprints on the moon.

[00:12.11] They also left two pairs of boots, a handful of tools, and four vomit bags.

[00:17.95] This lunar litter was far from the last space junk humanity has produced.

[00:23.26] In 2006, Suni Williams lost her camera while tussling with a stuck solar array on the ISS.

[00:33.36] And the following year, a similar job resulted in the loss of a bag filled with $100,000 worth of tools.

[00:39.20] These accidental satellites typically have short lifespans, before falling back to Earth and burning up in our atmosphere.

[00:46.91] However, other pieces of space junk, like SpaceX’s Tesla Roadster, will be stuck in their orbits for the foreseeable future.

[00:55.14] In the early days of space travel, this kind of littering was largely considered inconsequential.

[01:01.52] But in today's crowded skies, orbital debris poses a serious threat to the thousands of satellites that underpin Earth’s vital technologies.

[01:12.41] Currently, there are over 131 million pieces of debris whipping around the planet at an average speed of 10 kilometers a second.

[01:22.24] This debris ranges in size from pieces as large as an entire bus, to those as small as a grain of sand.

[01:30.47] But roughly 1 million pieces are at least one centimeter across, which is large enough to severely damage most satellites.

[01:38.71] While losing any spacecraft is bad enough, the knock-on effects are even worse.

[01:44.55] 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.

[01:57.30] 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.

[02:15.10] But what does all this mean for people on Earth?

[02:16.69] Well, even if space shrapnel does take down a satellite, most debris burns up during re-entry.

[02:24.66] So the probability of waking up to a spacecraft in your yard is very small.

[02:28.11] That said, some large specimens can survive the trip, such as the SpaceX Capsule that landed in an Australian field in August of 2022.

[02:39.00] And the odds of something similar happening again grows alongside the amount of space junk.

[02:45.12] So how can we save our satellites and ourselves from all this trash?

[02:49.90] Part of the solution is to stop creating waste in space, but debris is generated in a lot of ways.

[02:58.40] In addition to collisions, solar radiation erodes spacecraft surfaces, motors spew slag, and satellite launches routinely abandon rocket bodies, covers, cowlings, and explosive bolts.

[03:12.74] Since 1957, we’ve ferried almost 16,000 satellites to space using thousands of disposable rockets.

[03:22.57] Researchers are finally experimenting with new systems that can send up over 100 satellites in a single rocket launch.

[03:30.54] Meanwhile, both NASA and private companies are working to prevent existing satellites from becoming junk by using servicer satellites to refuel, inspect, and repair them.

[03:42.76] But we also need to clean up the junk that's already up in orbit.

[03:47.54] When a satellite is ready to retire, engineers can use controlled re-entry to intentionally burn it up in Earth's atmosphere. Ideally, this would happen as soon as a satellite is out of use, but outside the US, current guidelines allow defunct satellites to remain in orbit for up to 25 years, but this rule has barely been enforced.

[04:10.12] Beyond retired spacecraft, researchers have identified some particularly dangerous debris, so efforts could be made to tackle them first.

[04:18.88] Some debris experts have proposed using lasers, based both on Earth and in space, to nudge small debris to a higher, safer orbit or into the atmosphere.

[04:30.31] And private companies are attempting to use space tug boats to ferry large debris to less dangerous orbits.

[04:38.28] Whatever the solution, all these satellites and orbital debris reflect human consumption back on Earth.

[04:45.45] So if we want to keep using and exploring this final frontier, we'll need to get better at cleaning up our trash both up there and down here.