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US confirms for first time it has deployed space weapons

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Re: US confirms for first time it has deployed space weapons

#231

Post by toast0 »

lr1970 wrote: post #128
mapt wrote: post #100

Earlier quoted context omitted.

A bullet travels at a relative speed of about 250 to 1250m/s. A ~10g projectile moving that fast has an energy of 600-16000 joules. Everything in low Earth orbit is moving at 7600m/s. A ~10g projectile moving that fast has an energy of 580,000 joules. Getting hit by something moving that fast is roughly equivalent to getting hit by a whole ammo case of bullets at the same speed. There is no armor that can protect you…

> Everything in low Earth orbit is moving at 7600m/s. A ~10g projectile moving that fast has an energy of 580,000 joules. What matters is the relative velocity of the projectile towards the target. I practice it will be smaller or larger (if the bullet is incoming). But steering an incoming projectile is way harder.

> But steering an incoming projectile is way harder.

It's usually much easier to steer an outgoing projectile. :P

Re: US confirms for first time it has deployed space weapons

#232

Post by bob1029 »

tonic_note wrote: post #226

It's most likely space-based missile defense, perhaps DOD secretly revived the Brilliant Pebbles ( https://en.wikipedia.org/wiki/Brilliant_Pebbles ) program? People hear "space weapons" and think Rods from God ( https://en.wikipedia.org/wiki/Kinetic_bombardment ) but hitting a precise target on the ground from space is really hard, like tying to hit a bull's eye from hundreds of miles away. The more practical applica…

> but hitting a precise target on the ground from space is really hard

Guidance systems exist. Kinetic != unguided.

Re: US confirms for first time it has deployed space weapons

#233

Post by onion2k »

Fwirt wrote: post #209
onion2k wrote: post #202

Earlier quoted context omitted.

What matters is the relative velocity of the projectile towards the target. True. If you really want to mess space up forever you need to launch a rocket full of sand, slingshot around the moon, and gently sprinkle it in an retrograde orbit. That would be fast enough for something as small as a grain of sand to create pinhole-sized punctures in anything put in orbit, and after a few years the sand would be spread out…

Space is really, really big. I think it's hard for us to comprehend just how much space is in space, especially in 3-dimensional terms. It would take a lot of sand to mine all of the useful orbital space, and that's just LEO. There's tons of room in higher orbits. It would measurably increase the risk of passing through LEO on the way to other destinations and make some orbital planes unusable for e.g. Starlink or hu…

It would take a lot of sand to mine all of the useful orbital space, and that's just LEO.

Nope. You just need to make it a high enough probability of your spaceship being damaged that people won't take the risk. For humans that's very low. For anything moderately expensive it's quite low.

There's tons of room in higher orbits.

You have to go through the lower orbits to get there.

Re: US confirms for first time it has deployed space weapons

#234

Post by consumer451 »

tonic_note wrote: post #226

It's most likely space-based missile defense, perhaps DOD secretly revived the Brilliant Pebbles ( https://en.wikipedia.org/wiki/Brilliant_Pebbles ) program? People hear "space weapons" and think Rods from God ( https://en.wikipedia.org/wiki/Kinetic_bombardment ) but hitting a precise target on the ground from space is really hard, like tying to hit a bull's eye from hundreds of miles away. The more practical applica…

The more practical approach appears to be fully on-orbit activities, as those are currently far harder to attribute. The field of "Space Domain Awareness" is still nascent and rapidly evolving.

See my other comment for my expanded take on this, informed by being a peaceful space-nerd who cannot seem to avoid this topic, even if I tried:

https://news.ycombinator.com/item?id=49711876

Re: US confirms for first time it has deployed space weapons

#235

Post by consensus1 »

MattPalmer1086 wrote: post #26
consensus1 wrote: post #12

Earlier quoted context omitted.

You actually think they don't already?

What would be the point? MAD relies on everyone knowing you can take them out if they attack you. What does a space weapon offer additionally that makes the huge expense worthwhile?

Controlling the high ground has been a critical element of warfare ever since the primary weapons were spears. If you want to claim that isn't the case then the burden of proof is on you.

Re: US confirms for first time it has deployed space weapons

#236

Post by JumpCrisscross »

onion2k wrote: post #233
Fwirt wrote: post #209

Earlier quoted context omitted.

Space is really, really big. I think it's hard for us to comprehend just how much space is in space, especially in 3-dimensional terms. It would take a lot of sand to mine all of the useful orbital space, and that's just LEO. There's tons of room in higher orbits. It would measurably increase the risk of passing through LEO on the way to other destinations and make some orbital planes unusable for e.g. Starlink or hu…

It would take a lot of sand to mine all of the useful orbital space, and that's just LEO. Nope. You just need to make it a high enough probability of your spaceship being damaged that people won't take the risk. For humans that's very low. For anything moderately expensive it's quite low. There's tons of room in higher orbits. You have to go through the lower orbits to get there.

> You have to go through the lower orbits to get there

Math doesn't math.

The closest solution I've seen is putting 10^6 to 10^9 kg fragmented debris in the 700 to 1,000 km band to create a 5% failure rate at fastest transit, which is economically devastating. But that assumes away grain-grain collisions.

I think when I last ran the math, you'd need to sustain 5 to 10 Starship loads of fragmented debris to that orbit a week to create a proper barrier–near 100% hazard. At which point the solution becomes shooting down those launch vehicles. In a couple years (3 to 10, depending on the solar cycle), the skies would clear to about 1% hazard. That hazard, however, would persist for some time–how long is anybody's guess.

Re: US confirms for first time it has deployed space weapons

#237

Post by freebsd_lovefes »

wat10000 wrote: post #223
ctkhn wrote: post #219

Earlier quoted context omitted.

If someone launched a nuke in space how would other nuclear powers react? I doubt they would assume "this is probably just an EMP and not a direct nuclear strike on our territory"

If you had time to plan it, you'd probably want to put the warhead on a satellite launched by a normal satellite launcher. It'll look benign until you detonate it.

Plot twist - someone has already thought about this and took measures of unimaginable scale...so that, no one, ever, wipes out, humanity, with nukes.

Re: US confirms for first time it has deployed space weapons

#238

Post by JumpCrisscross »

hajile wrote: post #115
jillesvangurp wrote: post #112

Earlier quoted context omitted.

Space is more like international waters legally. The outer space treaty is rooted in maritime law principles. The Chinese and Russians are in no mood to slow down relative to the US. There will likely be some escalation in debris and damage resulting from that might eventually result in some kind of action. But most of the damage here would be economical and sending more stuff up is now very cheap. Manned flight is r…

SpaceX satellites are doing about 1000 collision avoidance maneuvers every single day. The addition of new networks is going to congest things even more and the risk of unavoidable cascading failure keeps increasing at a massive rate.

> SpaceX satellites are doing about 1000 collision avoidance maneuvers every single day

Genuine question: how many avoidance maneouvres does maritime traffic execute in the open ocean?

Re: US confirms for first time it has deployed space weapons

#240

Post by JumpCrisscross »

ctkhn wrote: post #219
mschuster91 wrote: post #208

Earlier quoted context omitted.

> Adding a few thousand more pieces of debris would not be even remotely as bad as using a tactical nuclear weapon in war would be. The worst effect would be a nuclear weapon in space. The resulting EMP would probably fry more than enough electric and electronic devices to throw back whatever country is hit by it by decades .

If someone launched a nuke in space how would other nuclear powers react? I doubt they would assume "this is probably just an EMP and not a direct nuclear strike on our territory"

> If someone launched a nuke in space how would other nuclear powers react?

We'd bitch and moan and then carry on as usual. Nobody is starting thermonuclear war over fried birds. Maybe someone gets tariffed.

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