4 ms·

great move, we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink (ofc that's vanishingly unlikely, b

great move, we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink (ofc that's vanishingly unlikely, but it's important to understand that continual maneuvering is what keeps space accessible to humanity) anything we can do to lower that risk is a good move, and dropping 70km of elevation for the largest satellite constellation is definitely going to make a dent in the risk profile https://arxiv.org/pdf/2512.09643 https://arxiv.org/pdf/2512.09643 i hope to see progress with air breathing ion engine satellites in the coming years to further lower the minimum altitudes that these constellations can operate at

JumpCrisscross 10mo ago
> we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink To be clear, we’d be at risk of losing those specific orbits for a few years. Nothing would block all orbits much less access to space. And nothing above those orbits would be any more statistically likely to suffer an impact afterwards.
- quailfarmer 10mo ago
  For these large constellations, vehicles are generally raised slowly at the beginning of their lives, and debris spreads out as it decays downwards. A significant increase in debris at 550km would have an impact on all orbits below it, including all vehicles raising through that debris zone.
  - JumpCrisscross 10mo ago
    > A significant increase in debris at 550km would have an impact on all orbits below it, including all vehicles raising through that debris zone Space is huge. Try this trick: the number of satellites in orbit is about the same as the number of planes in the air at any time. (~12,000 [1][2].) The volume of space from the ground to 50,000 feet is about 200x smaller than the volume from the Karman line to the top of LEO alone (~2,000 km). Put another way, we approach the density of planes in the sky in LEO when there are milliions of satellites in that space alone. Picture what happens if every plane in the sky fell to the ground. Now understand that the same thing happening in LEO, while it occurs at higher energy, also occurs in less-occupied space and will eventually (mostly) burn up in the atmosphere. Put another way, you could poof every Starlink simultaneously and while it would be tremendously annoying, most satellites orbiting lower would be able to get out of the way, those that couldn't wouldn't cause much more damage, the whole mess would be avoidable for most and entirely gone within a few years. There are serious problems with space pollution. Catastrophic Kessler cascades that block humans from space, or knock out all of our satellites, aren't one of them. [1] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of... [2] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of...
    - Veedrac 10mo ago
      > The volume of space from the ground to 50,000 feet is about 200x smaller than the volume from the Karman line to the top of LEO alone (~2,000 km). Volume is the natural way to assume space scales, but it's incorrect. Two planes can fly parallel, side by side. Two satellites cannot orbit side by side. In the limit, if Earth had a solid ring of infinitesimal width, it would take zero volume but all orbits.
Veedrac 10mo ago
The paper says we are 2.8 days away from a collision. It doesn't say we're '2 days away from kessler'. In fact, the paper explicitly warns against your interpretation. > We emphasize that the CRASH Clock does not measure the onset of KCPS, nor should it be interpreted as indicating a runaway condition.
- thot_experiment 10mo ago
  Thanks, I stand corrected. I'll do a better job reading next time.

JumpCrisscross 10mo ago

> we're continually about 2 days away from kessler if we lost maneuvering control on a constellation like starlink To be clear, we’d be at risk of losing those specific orbits for a few years. Nothing would block all orbits much less access to space. And nothing above those orbits would be any more statistically likely to suffer an impact afterwards.

quailfarmer 10mo ago
For these large constellations, vehicles are generally raised slowly at the beginning of their lives, and debris spreads out as it decays downwards. A significant increase in debris at 550km would have an impact on all orbits below it, including all vehicles raising through that debris zone.
- JumpCrisscross 10mo ago
  > A significant increase in debris at 550km would have an impact on all orbits below it, including all vehicles raising through that debris zone Space is huge. Try this trick: the number of satellites in orbit is about the same as the number of planes in the air at any time. (~12,000 [1][2].) The volume of space from the ground to 50,000 feet is about 200x smaller than the volume from the Karman line to the top of LEO alone (~2,000 km). Put another way, we approach the density of planes in the sky in LEO when there are milliions of satellites in that space alone. Picture what happens if every plane in the sky fell to the ground. Now understand that the same thing happening in LEO, while it occurs at higher energy, also occurs in less-occupied space and will eventually (mostly) burn up in the atmosphere. Put another way, you could poof every Starlink simultaneously and while it would be tremendously annoying, most satellites orbiting lower would be able to get out of the way, those that couldn't wouldn't cause much more damage, the whole mess would be avoidable for most and entirely gone within a few years. There are serious problems with space pollution. Catastrophic Kessler cascades that block humans from space, or knock out all of our satellites, aren't one of them. [1] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of... [2] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of...
  - Veedrac 10mo ago
    > The volume of space from the ground to 50,000 feet is about 200x smaller than the volume from the Karman line to the top of LEO alone (~2,000 km). Volume is the natural way to assume space scales, but it's incorrect. Two planes can fly parallel, side by side. Two satellites cannot orbit side by side. In the limit, if Earth had a solid ring of infinitesimal width, it would take zero volume but all orbits.

Veedrac 10mo ago

The paper says we are 2.8 days away from a collision. It doesn't say we're '2 days away from kessler'. In fact, the paper explicitly warns against your interpretation. > We emphasize that the CRASH Clock does not measure the onset of KCPS, nor should it be interpreted as indicating a runaway condition.

thot_experiment 10mo ago
Thanks, I stand corrected. I'll do a better job reading next time.