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Comment by ljsprague

14 hours ago

I would guess that it would still be possible to send things beyond earth's orbit with only a low probability of collision with debris but perhaps I'm wrong.

"Low" is tough to say until someone does some proper sort of 'true mapping' of space debris in the range somehow. Protection would require a lot of complexity and cost due to the need for shielding and the delta-v to move it up there.

  • > until someone does some proper sort of 'true mapping' of space debris in the range somehow

    You look at which satellites poofed and then figure out the maximum extent their debris could have drifted.

    • That works a little bit when we're talking about one satellite poofing in a year based on a collision with another satellite, and not at all when we're talking about thousands of events a year, many of which are satellite-debris collisions too small to track (you only get one orbital vector), or between pieces of debris.

      Every collision generates hundreds, maybe thousands of pieces of debris, only the largest of which are trackable.

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  • Rather than protection on each rocket, couldn't you just send a bunch of fortified rockets that absorb the debris during a collision but don't emit anything. Do that a few times and then all other rockets just reuse the path that was cut?

    • Orbit is not a location. Orbit is a group of velocity-location vectors which form a stable loop around a body, without intersecting that body.

      Imagine a bullet circling your head at mach 25. Now imagine a second bullet, circling your head at a slightly different angle, at a slightly different distance from your head. There's a chance that they could collide, and the resulting explosion would leave a great deal of dust... on a mixture of velocities, still circling your head. Now add a third bullet, also on a slightly different vector; Make sure that it doesn't collide with any of that dust!

      The actual situation is we aren't dealing with 3 bullets or 100 bullets, we have ~170 million objects orbiting the Earth, and only around 50,000 are large enough to track. They are all moving fast enough in relation to each other that a collision would result in a sizable explosion, not an elastic agglomeration. We have no way of removing them.

      The good news is that there is a large volume of space for them to exist in. The bad news is that as we continue to fill it up, odds of collisions increase, and every collision spawns many, many more objects.

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    • > couldn't you just send a bunch of fortified rockets that absorb the debris during a collision but don't emit anything.

      "Just" how? Orbital collisions happen at an average of 10km/s, you're going to make what, some kind of sponge that can get hit by a chunk of satellite going ~8x faster than a bullet and absorb it and slow it to a halt without fragmenting at all? Good luck.

      > Do that a few times and then all other rockets just reuse the path that was cut?

      Things in orbit are constantly moving, you can't "clear a path" any more than you can, IDK, make a safe route through a forest by walking through it once and moving any bears you encounter a couple of feet.

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Every launch failure will result in more debris and even lower probability of a successful future launch.