How much space is there in space?

Ajouté : 2026-06-07

[00:00:00]Right now, as you watch this video, there are more than 43,000 objects being tracked [music] in orbit around Earth.

[00:00:06]Of those 43,000, only about 15,600 are working satellites. The rest, dead satellites, spent [music] rocket stages, shrapnel bolts, paint chips, and even a spatula that floated out of the space shuttle [music] in 2006.

[00:00:23]And those are just the ones that we can track. Scientists estimate that there are over 1.2 million pieces of debris larger than 1 cm that we cannot even see. The main problem here is that as our skies become ever more full, we drastically increase the risk of one tiny piece of floating metal setting off a catastrophic chain of events that could see mass communication outages, loss of scientific equipment, [music] and rain and debris falling from the sky. The question is, how close are we really to this happening? And what is being done to stop it?

[00:01:00]Let's start with something that sounds simple, but isn't. Where do you actually put a satellite?

[00:01:12]Space isn't a blank canvas. There are very specific physics-defined bands around the Earth where satellites can actually function. Go too low, the atmosphere drags you back and burns you up. Go too high, invisible belts of radiation fry your electronics. And between, that's the orbital real estate, and it's filling up fast.

[00:01:34]There are three main altitude zones.

[00:01:37]First, low Earth orbit, or LEO. This starts at about 160 km above Earth's surface and goes up to 2,000 [music] km, covering 309 billion cubic miles of space. This is where most of the action is.

[00:01:53]The International Space Station, Starlink satellites, and Earth observation satellites. 75% of all cataloged objects in orbit are here in LEO. This not only represents the most densely populated portion, but also the smallest by volume, and where the key problematic area is. However, the advantage of lower Earth orbit is this: speed and signal strength. Satellites here are close enough that data travels fast, just 20 to 100 milliseconds of latency. Your Netflix buffer barely notices. But at these altitudes, Earth's gravity still has a strong grip.

[00:02:32]Satellites need to travel at roughly 7.8 km [music] per second, around 28,000 km per hour, just to stay in orbit.

[00:02:41]Which means that if they slow down even slightly, they fall.

[00:02:46]Second zone, medium Earth orbit, MEO.

[00:02:50]From 2,000 km all the way up to around 35,000 [music] km.

[00:02:55]This is 31 quadrillion cubic miles.

[00:02:59]This is where GPS satellites live. Your phone knows where you are right now because of a constellation of 31 satellites sitting medium Earth orbit, at about 20,200 [music] km up. And third, geostationary orbit, GEO.

[00:03:15]Exactly 35,786 km above the equator, this is the sweet spot where a satellite orbits at exactly the same speed as Earth rotates. So, from the ground, it looks like it's standing still. That's why your satellite TV dish is fixed.

[00:03:33]It points at a specific [music] spot in the sky and never has to move. But there's a trade-off. The signal from a GEO satellite has to travel over 35,000 km up to the satellite and another 35,000 km back down. By the time that the data completes a full round trip network ping, you're looking at 500 to 700 milliseconds of latency. [music] That's why old satellite internet was so frustrating for gamers or video calls.

[00:04:00]So, other than latency, why can't we just push everything higher since there seems to be more room up there? There are two main reasons for this.

[00:04:09]First, the Van Allen radiation belts.

[00:04:12]These are two donut-shaped rings of high-energy charged particles trapped by Earth's magnetic field.

[00:04:18]The inner belt starts just a thousand kilometers up and peaks around two to five thousand kilometers.

[00:04:25]Electronics exposed to the inner belt degrade rapidly.

[00:04:29]Sustained operation in there is essentially impossible for most hardware. Second, signal physics. The power of radio signal decreases with the square of the distance.

[00:04:40]Double the altitude and the signal is four times weaker. At GEO, you're already at the edge. Go higher and you need increasingly massive antennas to power the source to maintain communications. [music] The economics stop working.

[00:04:54]And why can't we go lower?

[00:04:57]Because at altitudes below 300 kilometers, Earth's atmosphere, thin as it is, still creates enough drag to slow satellites down.

[00:05:05]Orbital decay sets in within weeks.

[00:05:08]That's actually useful for disposing of dead satellites, but it also means that anything below 300 kilometers is a temporary resident. Here's the critical part. At 500 kilometers, where many Earth observation satellites operate, atmospheric drag is still there, but very faint. A dead satellite can stay up here for several years before dropping, but past 700 or 800 kilometers, where many older satellites and debris clusters sit, and the atmosphere is so nearly non-existent that a piece of junk can remain trapped in orbit for hundreds of years.

[00:05:43]Now, let's put numbers to this. If you look at the data, the scale the problem depends on who you ask, but both answers are alarming. According to the ASCCU space debris report, which relies on strict catalog data, there are 33,269 major objects explicitly tracked in orbit. Of those, 17,682 are classified as payloads, while the rest are a mix of spent rocket bodies and debris fragments.

[00:06:13]On paper, that means nearly 47% of what's up there is verified space junk.

[00:06:19]But, the European Space Agency paints an even more urgent picture.

[00:06:24]The ESA's real-time monitoring network tracks a broader pool of over 40,000 total objects.

[00:06:30]And here's the kicker. ESA estimates that only about 11,000 of those are active working payloads. When you bridge the gap between these two reports, a sobering truth emerges. Between dead satellites that are no longer controlled and the shattered fragments of old space missions, up to 70% of the tracked objects currently screaming around our skies serve absolutely no purpose. In 2024 alone, over 3,000 new tracked objects were added as the result of fragmentation events, explosions, collisions, and breakups.

[00:07:03]And below that, the invisible layer, an estimated 1.2 million pieces of debris between 1 cm [music] and 10 cm that no telescope or radar can reliably track.

[00:07:14]Too small to see, big enough to destroy a spacecraft on impact. The ASCCU report tracks which countries [music] contribute to the most debris. The top three, China, the US, and the CIS, which is the Commonwealth of Independent States. Russia scores the highest historically.

[00:07:33]Russian-origin debris comes [music] from the old Soviet Cosmos program. Hundreds of military satellites from from 1970s and '80s, many of which broke apart.

[00:07:44]Some were nuclear-powered.

[00:07:47]On the other hand, China leads by debris intensity score by country, which is the number of debris objects in orbit per active satellite. China had a single event that changed the debris landscape permanently. In 2007, China tested an anti-satellite missile by destroying one of its own weather satellites, Fengyun-1C, at 865 km's altitude. That single explosion created roughly 3,000 trackable fragments and an estimated 35,000 pieces of debris larger than 1 cm. Most of that debris will remain in orbit for decades. In August 2024, a Chinese Long March 6A rocket broke apart in lower Earth orbit. 700 confirmed fragments, possibly more than 900, in one event. That is the scale of risk we're dealing with.

[00:08:39]In 1978, NASA scientist Donald Kessler published a paper. He described a scenario so concerning that space agencies still talk about it today.

[00:08:50]He called it the collision cascade.

[00:08:52]The idea is this: at certain density of objects in orbit, a single collision creates debris. That debris hits other satellites and debris creates more debris, which hits more things. An exponential chain reaction that we cannot stop and it cannot be cleaned up fast enough because new debris is being created faster than it decays. Here's the physics that make this terrifying.

[00:09:16]Debris in lower Earth orbit travels at 7 to 8 km's per second. That's 25,000 km's per hour. A fragment the size of a marble carries the kinetic energy equivalent to a hand grenade.

[00:09:29]A 10-cm piece is a car crash at those speeds. In 2009, an American Iridium communication satellite and a defunct Russian Cosmos military satellite collided at 789 km altitude. Neither saw it coming. There was no warning systems capable of preventing it. The collision generated more than 2,000 trackable pieces of debris that still up there today.

[00:09:55]Scientists now believe that in certain altitude bands, particularly between 900 and 1,000 km, the debris density has already crossed the threshold where Kessler's cascade is theoretically self-sustaining.

[00:10:09]Even if we stop launching satellites tomorrow, collisions in those bands would continue to generate debris for centuries. Here's where it gets interesting because the world is starting to take this seriously and there's real money flowing into solving it.

[00:10:23]The global space debris monitoring and removal market is worth approximately 1.14 billion dollars in 2025 and is projected to grow to 1.68 billion dollars by 2030.

[00:10:36]A problem created largely by governments is now being solved at least partially by private enterprise. The most ambitious active debris removal mission is ClearSpace One, a European Space Agency project. A four-armed robotic spacecraft designed to grab a defunct rocket part called Vespa that has been orbiting since 2013.

[00:10:58]This will be one of the first times in history a dedicated commercial mission captures and deorbits a [music] piece of non-cooperative legacy junk. Japanese company Astroscale [music] has raised over 384 million US dollars to develop debris capture hardware. There's also a regulatory push. The FCC in the United States now requires new satellites in low Earth orbit to deorbit within five years of end of mission.

[00:11:24]The old rule was 25 [music] years.

[00:11:27]That change came into effect in 2022, but it only applies to new satellites.

[00:11:32][music] The legacy debris, nobody's paying for that.

[00:11:37]Here is the uncomfortable truth.

[00:11:39]The satellites we depend on every day for GPS, weather forecasting, internet communications, banking, and military coordination are operating in the same orbital shell that are increasingly being choked with debris. The physics of orbital mechanics gave us a Goldilocks zone.

[00:11:58]Not too low, not too high. The right altitude for the right purpose. But nobody planned for what happens when that zone gets full. After all, 309 billion cubic miles is a lot to fill.

[00:12:12]However, space technology is on the rise, and when you launch a satellite and it dies, it doesn't fall. [music] It stays for decades, sometimes even centuries. Under international law, debris always belongs to the country that launched it. Meaning, you can't clean up another nation's junk without starting a diplomatic crisis.

[00:12:33]Yet, there is no binding treaty forcing them to clean it up themselves.

[00:12:38]There's no global insurance scheme, no international cleanup fund, and no enforceable penalty for littering the cosmos. We are a few bad decisions away from a chain reaction that could be highly problematic for many day-to-day pieces of consumer tech, city infrastructure, and governmental operations. Solutions are coming, but with more and more satellites launching almost every week, will they be here quick enough?