The rods from God’s idea is insane and won’t work.
We had this back when the Russians announced they were going to drop conventional ordinance from space, and everyone pointed out that they would be lucky to hit the right continent, let alone Ukraine. In order to make this actually work, you would have to have an active aiming system. Which you know, is a missile.
The launch platform can aim it and use math to account for gravity, the atmosphere and all that jazz to hit the target at least close enough. Just like we already do to safely crash/burn up space debris.
at least close enough
To whose standards exactly? Dick Cheney’s?
No, they can’t. The atmosphere is an unknown state, different temperatures, different densities, different wind directions, none of which can be known ahead of time. That’s why weather forecasting is always approximate. You get a percentage chance that it’ll rain. You don’t get a definite time stamp with 100% accuracy.
We cannot predict atmospheric disturbances to the level necessary to make this a practical system. When they burn up space debris they do it “somewhere over the middle bit of the Atlantic” That’s about the level of definition you get. It’s not accurate at all.
no, not really, it still gives you multiple km spread
this ignoring the tiny little issue of overheating during reentry
Well that’s why one of the proposed materials is tungsten, the problem with that being that tungsten is a bit heavy.
Gram of tungsten has a mass of something like 15 grams
I’m referring to Rogozhin’s idea of putting FAB-500s as a payload, boompaste doesn’t tolerate such conditions
A gram of tungsten weighs 15 grams?
That’s not… how… weight works.
Gram of tungsten has a mass of something like 15 grams.
Yeah, probably not.
19.3 g/ cm3
heavy is one of the advantages though. kinetic mass in a smaller morr aerodynamic package
You could use trajectory, distance, etc like we already do with long range rifle marksmanship but add some crazy sight that does all the math to make it work to avoid being considered a missile. It may end up being as big as one, but that divine sight works on my non existent whiteboards lol
Way too many variables to accurately fire an inert projectile through that much atmosphere without being guided at least part of the way.
So no one considers moon a weapon of m.ass destruction? All it needs is a fairly good booster on the far side …
There has actually been multiple occasions were Russia was caught trying to break that treaty, kind of interesting to think about. The question is if Russia does actually mobilize an orbital nuclear weapon someday like an advanced Sarmat or some kind of space bomber, will the nations of the world act in unison or watch in silence?
Have fun with that existential dread while I work on my laundry.
They are super far from having that kind of money. Anyways the US would know early enough to stop it.
True I bet the Russian Oligarchs would secretly siphon that project’s funds in moments, just like they did to the Russian Navy.
I’m gonna leave this here. Excellent video by Veritasium, looking at the practicality and plausibility of “rods from god”
From a purely physical point of view, is that realistic?
If all of its energy is kinetic, it means that the energy must result from it’s potential energy+any fuel it is propelled with. Ignoring air-friction and terminal velocity for free falling objects, that means that still the energy of a nuclear weapon is required to bring this thing up into space, or stored as fuel for its propulsion.
So unless the projectile is assembled in space, any rocket bringing it into space will contain at least the energy of a nuclear warhead. Gotta be a very nervous launch, knowing that any failure will result in a fire with the energy of a nuke.
A lot of the energy comes from orbital speeds.
The Hypervelocity Rod Bundles project proposed 6,1x0,3 m tungsten rods, weighing about 8200 kg, impacting at about 3000 m/s, meaning about 42 GJ of energy per projectile [wikipedia].
The weakest recorded nuke, the Davy Crocket Tactical Nuclear Weapon, is estimated at about twice that (84 GJ), and the largest, Tsar Bomba, at about 3 000 000x the yield (210 PJ).
That’s their point, how do you get such a heavy thing to orbital speed without spending all that energy? You can’t unless you build it from materials harvested in space.
Oh, I apologise, I suffered some curse of knowledge there, the answer is time.
A blast is a release of energy over a short time, the whole point of building weapons is to store and handle energy in safe amounts over time.
Global electric energy consumption is about 200 PJ a day, approximately the same as the Tsar Bomba, but there’s no risk for a huge explosion neither when you incinerate trash or turn off the AC.
Because time.
Although we could explode a nuke and propel things ballistically, it turns out it’s a lot easier to use rockets. A rocket, although carrying frightening amounts of fuel and exploding spectacularly when it fires wrong, has several safeguards to not expend all that fuel at once. And also gives the opportunity to correct course along the way.
Now imagine that the same amount of energy has been expended many many many times over the course of the space era, and almost any mass in orbit has serious potential for damage.
For example, the MIR was 130 tons, orbiting at about 7,8 km/s, for a kinetic energy of 4 TJ, and another 235 GJ of potential energy. Totalling about a tenth of Little Boy that levelled Hiroshima.
Edit: Specifying and correcting the global energy consumption.
Right, and tungsten rods are dangerous because they don’t slow down and burn up in the atmosphere like most spacecraft do (like you said, spreading out that energy over time and space). As long as you can deorbit them accurately, they are devastating since they convert the entire orbital potential energy into surface kinetic energy all at once. (Oddly, orbital potential energy and surface kinetic energy are the same thing, just from different points of reference.)
Agreed. On all points.
Moreover, the Tungsten rods are quite dense and thus small, and thus very hard to spot on radar or hit with countermeasures.
One of the things that’s stuck with me during my time on Lemmy is someone remarking that the only difference between a battery and a bomb is how controlled the release of energy is. Having seen what happens when you puncture a LiPo battery, I believe it 😰
Fun fact, everything with a high velocity (and a certain mass) has a lot of kinetic energy.
(Now think of space ships going light speed. You don’t need photon torpedoes)
Inyalowda love rocks, so let’s give dem sum, sasa ke
Science fiction always challenges my suspension of disbelief is when people land on planets to skirmish with conventional weapons instead of, say, throw a big heavy aerodynamic solid rock from space.
Good sci-fi usually treats this on par with using nuclear weapons (which it kinda is?). In Babylon 5, mass drivers are banned by intergalactic treaty, and when one race uses them anyway it literally bombs their victims back into the stone age, and it’s treated as a horrifying event --one of the character’s defining moments in the show is just him looking on silently in horror.
Kinetic drives are mass drivers. Unless you use some kind of teleportation or space warping for travel, every ship is a weapon of mass destruction. Every old boat is a surprise WMD, every craft a viable nuke with zero preparation.
You can make good reasons or at least plausible ones. 40k has planetary shields. There could be a civil war so neither side might want to destroy the surfaces of each planet and civilians. Battletech has spaceship tech being rare and irreplacable, and there are treaties limiting orbital and nuclear bombardment.
Sometimes the most realistic route just isnt fun though so i can usually look past the contrivances.
In the Expanse series Earth and Mars are at war. They can easily throw rocks and totally destroy the other side. Not just beat them in a war, like totally wipe them out. But Mars knows if they start throwing rocks all bets are off and Earth will wipe them out. Just as Earth knows the same, if they wipe out Mars, Mars will make sure the Earth is destroyed.
It’s an analogy of the current situation we have with nuclear weapons. During the Cold War Russia made sure they could wipe out the US if the US ever tried a first strike and the US made sure they could wipe out Russia if they ever tried something. The Mutually Assured Destruction (MAD) prevented anyone from taking the first step. These days the playing field is a bit more complex, but the same principles hold for now.
Of course in the Expanse there is a third party with nothing to lose that at one point employs such a weapon of mass destruction. But let’s just hope that part isn’t a mirror for reality.
I see you’ve skipped the most advanced detection and targeting systems connected to a network of orbital railguns, and the fact all of that is constantly pointed at Mars in case they launch stealth nukes. Inarocks are not a valid war strategy, and only extreme levels of preparation and corruption allowed a few chunks to hit Earth.
Why in the hell would anyone bother though? First you got to launch all that mass into a stable orbit. Then you got to assemble the delivery system with the mass as it’s most definitely too heavy for a single launch. Then you need fuel to deorbit the mass when you launch because things in stable orbits tend to want to stay there. Then you wait for the mass to deorbit because we couldn’t afford to send enough fuel for a rapid deorbit. Also wait to launch till optimal trajectory for your target is achieved and hope that it’s not too far side to side from your orbital path because that means even more fuel to deorbit. Also anyone with a halfway decent telescope sees your weapon just sitting there in orbit not to mention being assembled so now it’s got a massive target painted on it at all times and is an easy casualty of first strike.
Or we could use the icbm’s that are a proven tech, easier to hide though that’s not foolproof, can be made mobile, much much more numerous, easier to protect from attack, much cheaper than launching tons of solid metal into orbit, and can strike anywhere on the globe within an hour.
I mean, launch costs are going down over time. It might make much more sense to put many warheads up with a reusable system like falcon (~3000$/kg) than it does to maintain a fleet of necessarily single-use systems like minuiteman (7,000,000$/~300kg = 23,300$/kg). You might well be able to put four warheads (with an equal mass of de-orbiting propellent into orbit - ~1.7 km/s given solid fuel) for the same cost as one ICBM.
The problem I remember is that it is expensive to get the rod up there in the first place.
Also every other nation would hate us and make jokes about the collective small penis of the US state.
Also the tungsten oxides produced in high velocity impacts are potentially worse than fallout.
lol “the United States state.”
Yes. The United States of America is, itself a federated state that also represents the fifty states. It’s why we have a state department and a Secretary of State in the White House.
I never said otherwise. Petition to call it the United States State from now on. Let’s also call the UK as the United State Kingdom State.
Ah yes, we would do that, definately haven’t already started… no, of course not.
It’s well within the character of the US federal government and the armed forces to go forward with an OWP platform program right now, even despite the risks and ethics concerns, sadly.
What about the Jewish Space Lasers that MTG said started the wildfires?
Magic The Gathering has a lot to answer for.
