31–40 of 105 posts
There are so many satellites in orbit that there is a pretty good chance that if even one was to be hit by something and explode in many pieces, it would crash another one and then another one until there is nothing left. The nasa is pretty scared of it, so is SpaceX.
Earlier quoted context omitted.
That's the Kessler Syndrome. But it's better if it happens in a lower orbit, irrespective of what assets are present there. Space will be free for exploration again in a few years since all the debris there would eventually decay and deorbit. The article mentions a few months at 480 km. I'm a little skeptical about this figure though, because the last tracked piece from an NRO satellite that was shot down at ~250 km…
Two objects colliding can send debris into different orbits. Combined kinetic energy and mass differences can send debris to many different orbits. A golf ball hitting a bowling ball or basketball, both traveling at 30 units of speed can produce quite a fast golf ball. Not all of the debris will safely burn up.
To circularize at a higher orbit you would need secondary collisions on the other side of the earth.
Earlier quoted context omitted.
There are tentative signs that this is happening right now. As in: each collision causes debris that on average causes more than one additional collision, causing collision rates to go up exponentially. But so far it's not anything like in Hollywood movies, it's just a graph slowly going up. There are about 12000 satellites orbiting earth. That looks like a lot on a map, but 12000 objects spread over an area larger t…
> 12000 objects spread over an area larger than the surface of the earth isn't all that much People keep saying this, but the only way to assure there is no collision is to have non-intersecting orbits, but that is not going to work: not enough space. It's a tell that SpaceX is now lowering the orbits, even though their satellites mostly move in flocks that maintain a formation relative to each other: because the oth…
Hard to see how the repositioning appreciably alters this risk, since there are still thousands of satellites in the original plane to get hit by shrapnel from intentionally caused collisions, and the satellites in the lower orbit aren't invulnerable to it either
Suspect there's a rather more practical calculation that the extra thruster firings needed to main position in a lower orbit with more atmospheric drag are offset by the smaller number of conjunction avoidance manoeuvres they need to undertake in less congested space (the cost of lowering the orbit is simply deducted from their original delta-v budget for end of life deorbiting). In simple terms they get lower accidental collision risk without operations in the lower orbit shortening satellite lifetime.
From a comment : >The first move in the coming WWIII, where the emperors try to expand their empires militaril,y will be to wipe out any orbit with Starlink satellites. I find this highly unlikely, given Starlink is soon to reached 10k satellites and will continue to grow. Why expand 10 000 ballistic missiles to bring down one of many communications networks ?
You could launch some missiles, blow a few satellites into smithereens, and gradually over the next few months they would take out the others. That's a poor kind of war weapon. An effective weapon is one where you can inflict damage continuously, and are able to stop immediately upon some concession. If you can't offer to stop in return for concessions, you won't get any.
As soon as a satellite is hit the rest of the fleet can start thrusting and raise their orbits to create a clear separation to the debris field.
Following such an attack the rest of the fleet would of course spread out across orbital heights and planes to minimize the potential damage done by each hit, leading to maximum cost for the adversary to do any damage. Rather than like today where the orbits are optimized for ease of management and highest possible bandwidth.
Earlier quoted context omitted.
That's the Kessler Syndrome. But it's better if it happens in a lower orbit, irrespective of what assets are present there. Space will be free for exploration again in a few years since all the debris there would eventually decay and deorbit. The article mentions a few months at 480 km. I'm a little skeptical about this figure though, because the last tracked piece from an NRO satellite that was shot down at ~250 km…
It's one reason why space should be regulated (but globally / internationally), the systems in place are kinda loose and more of a gentleman's agreement insofar as I understand it. A plan for decomissioning / de-orbiting stuff should definitely be mandatory. I know there's an area for geostationary sattelites to park themselves after their lifespan, for example. But the LEO ones like Starlink will see their orbit dec…
There are so many satellites in orbit that there is a pretty good chance that if even one was to be hit by something and explode in many pieces, it would crash another one and then another one until there is nothing left. The nasa is pretty scared of it, so is SpaceX.
Let us say that you had 10 thousand people running around on Earth, including all the oceans and Antarctica, and that collision of any two would release a hail of small deadly darts into the troposphere lasting, for, at 2 years or so. Which is approximately how long debris will last on LEO, though the actual values vary.
You still wouldn't expect all those 10 thousand people to obliterate themselves like that, as the Earth's surface is pretty darn big.
The volume of the LEO-relevant space is much bigger than the volume of the entire troposphere on Earth, because a) it is further away from the Earth's center than the troposphere, b) it is much deeper.
Now, 10 million objects, that would be a different story. So would be some specific peculiar orbit which is overcrowded. But tens of thousands of objects spread all over the entire planet isn't that much. That would be like 2-5 people in total roaming the entire Czechia, how often would they come into contact? Not very often.
Earlier quoted context omitted.
> 12000 objects spread over an area larger than the surface of the earth isn't all that much People keep saying this, but the only way to assure there is no collision is to have non-intersecting orbits, but that is not going to work: not enough space. It's a tell that SpaceX is now lowering the orbits, even though their satellites mostly move in flocks that maintain a formation relative to each other: because the oth…
> The major reason to lower these orbits is likely the risk of a terrorist state turning these constellations into a weapon, by willingly causing the Kessler syndrome. Hard to see how the repositioning appreciably alters this risk, since there are still thousands of satellites in the original plane to get hit by shrapnel from intentionally caused collisions, and the satellites in the lower orbit aren't invulnerable t…
Yes, but the lower the orbit, the faster atmospheric drag (which isn't zero, just low) cleans up a cascade.
There are so many satellites in orbit that there is a pretty good chance that if even one was to be hit by something and explode in many pieces, it would crash another one and then another one until there is nothing left. The nasa is pretty scared of it, so is SpaceX.
small price to pay for global internet