What do mega-constellations of thousands of satellites mean for the near-Earth space environment in the long term?

Alright, let's talk about this. Imagine the space hundreds of kilometers above our heads, Low Earth Orbit (LEO), which used to be relatively empty. Now, suddenly, thousands or even tens of thousands of small satellites are being crammed into it, turning it into a super busy "aerial interchange." In the long run, this will trigger a series of chain reactions.

1. Space Will Become Extremely Congested, and Collision Risk Will Skyrocket

This is perhaps the most direct and dangerous problem.

• Traffic Density: The number of satellites will jump from hundreds or thousands to tens of thousands. Orbits are like highways; traffic volume surges, but the roads don't widen, naturally leading to a sharp increase in the probability of scrapes and collisions.
• Space Debris: When satellites collide with each other, or with existing space debris (like defunct satellites, rocket remnants), they don't just stop like ground accidents. They crash at many times "bullet speed" (several to over ten kilometers per second), instantly shattering into thousands or tens of thousands of new fragments.
• Kessler Syndrome (Avalanche Effect): Even more terrifying, these new fragments will then collide with other satellites, generating even more fragments... This vicious cycle is like an avalanche. If it truly reaches that point, the entire Low Earth Orbit could become covered in debris, rendering it unusable. For decades, even centuries to come, we might be unable to safely launch new spacecraft, effectively "locking" us on Earth.

(The image is for conceptual illustration only)

2. An "Astronomer's Nightmare"

For astronomers, these tens of thousands of "light sources" are nothing short of a disaster.

• Light Pollution: The surfaces of these satellites reflect sunlight. When observing faint, distant galaxies with highly sensitive ground-based telescopes, a satellite flying by is like someone flashing a flashlight in front of your long-exposure camera, ruining the entire shot. Tens of thousands of satellites mean this "flashing" will become continuous interference.
• Radio Interference: Satellites need to communicate with the ground and thus emit radio signals. Radio astronomers study the universe by receiving faint radio signals from deep space. A mega-constellation is like building thousands of high-power signal base stations right next to a radio telescope that is "listening to the universe"; the immense noise would drown out those precious cosmic signals.

3. The Trouble After Satellites "Die a Natural Death"

These satellites are not permanent; their typical design life is 5 to 10 years. How to deal with defunct satellites is a major problem.

• Active Deorbiting: According to plan, these satellites will use their last bit of fuel at the end of their lifespan to lower their orbit and eventually burn up in the atmosphere. This is a responsible practice.
• "Zombie Satellites": But accidents happen. If a satellite suddenly loses control before deorbiting (e.g., hit by a small fragment, or electronic failure), it becomes an uncontrolled "zombie satellite," drifting at high speed in orbit, turning into a massive, extremely dangerous piece of space debris.
• Failure Rate Issue: Even if the satellite failure rate is very low, say just 1%. A constellation of 40,000 satellites would still mean 400 uncontrolled "time bombs" left in space. This number is quite astonishing.

In Summary

Simply put, mega-constellations offer conveniences like global internet coverage, but at a cost:

• Safety: Greatly increases orbital collision risk, potentially triggering a "debris avalanche," threatening all space activities.
• Science: Severely interferes with astronomical observations, effectively blinding and deafening our "eyes" and "ears" for exploring the universe.
• Environment: Creates a large amount of potential, difficult-to-clean space debris, polluting valuable orbital resources.

This is like a previously clear river where everyone, for convenience, starts frantically setting up fish farms. In the short term, individuals profit, but in the long run, the entire river might become blocked and polluted, eventually making it unusable for anyone. How to "legislate" space, establishing globally recognized "traffic rules" and "environmental standards," is a very urgent issue currently facing all humanity.