The space armament treaty says: no nuclear, biological or laser weapons in space. but kinetics...

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.

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.

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.

What about the Jewish Space Lasers that MTG said started the wildfires?

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.

This idea was used in The Moon Is A Harsh Mistress. They loaded up the cargo containers they were sending to Earth with rocks and used them exactly as dropping a rock on something to destroy it

Great book :)

If anyone wants some good sci-fi, I recommend The Expanse, both the books and the show. They make great use of kinetic impactors, especially Nemesis Games.

Except you can't just drop it. You need to push it out of orbit, and then push yourself back in

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)

We should just build space colonies and just drop those when needed

So no one considers moon a weapon of m.ass destruction? All it needs is a fairly good booster on the far side ...

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.

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.

Neil Tyson said this is entirely impractical.

Once we have mastered space travel, the most dangerous weapon that will be available to almost anyone will be firing an asteroid at a planet.

For another take on Kinetic impactors try The moon is a Harsh Mistress or as they call them. Tossing rocks down the gravity well.

Mollari disgust level: Rising.

I'm gonna leave this here. Excellent video by Veritasium, looking at the practicality and plausibility of "rods from god"

There was one in the G.I Joe movie.

https://en.wikipedia.org/wiki/Kinetic_bombardment

2003 United States Air Force proposal

A system described in the 2003 United States Air Force report called Hypervelocity Rod Bundles[10] was that of 20-foot-long (6.1 m), 1-foot-diameter (0.30 m) tungsten rods that are satellite-controlled and have global strike capability, with impact speeds of Mach 10.[11][12][13]

The bomb would naturally contain large kinetic energy because it moves at orbital velocities, around 8 kilometres per second (26,000 ft/s; 8,000 m/s; Mach 24) in orbit and 3 kilometres per second (9,800 ft/s; 3,000 m/s; Mach 8.8) at impact. As the rod reenters Earth's atmosphere it would lose most of its velocity, but the remaining energy would cause considerable damage. Some systems are quoted as having the yield of a small tactical nuclear bomb.[13] These designs are envisioned as a bunker buster.[12][14] As the name suggests, the 'bunker buster' is powerful enough to destroy a nuclear bunker. With 6–8 satellites on a given orbit, a target could be hit within 12–15 minutes from any given time, less than half the time taken by an ICBM and without the launch warning. Such a system could also be equipped with sensors to detect incoming anti-ballistic missile-type threats and relatively light protective measures to use against them (e.g. Hit-To-Kill Missiles or megawatt-class chemical laser). The time between deorbit and impact would only be a few minutes, and depending on the orbits and positions in the orbits, the system would have a worldwide range. There would be no need to deploy missiles, aircraft, or other vehicles.

In the case of the system mentioned in the 2003 Air Force report above, a 6.1 by 0.3 metres (20 ft × 1 ft) tungsten cylinder impacting at Mach 10 (11,200 ft/s; 3,400 m/s) has kinetic energy equivalent to approximately 11.5 tons of TNT (48 GJ).[15] The mass of such a cylinder is itself greater than 9 short tons (8.2 t), so the practical applications of such a system are limited to those situations where its other characteristics provide a clear and decisive advantage—a conventional bomb/warhead of similar weight to the tungsten rod, delivered by conventional means, provides similar destructive capability and is far more practical and cost-effective.[16][17][18]

The highly elongated shape and high mass of the projectiles are intended to enhance sectional density (and therefore minimize kinetic energy loss due to air friction) and maximize penetration of hard or buried targets. The larger device is expected to be quite effective at penetrating deeply buried bunkers and other command and control targets.[19]

The weapon would be very hard to defend against. It has a very high closing velocity and a small radar cross-section. The launch is difficult to detect. Any infrared launch signature occurs in orbit, at no fixed position. The infrared launch signature also has a much smaller magnitude compared to a ballistic missile launch. The system would also have to cope with atmospheric heating from re-entry, which could melt non-tungsten components of the weapon.[20]

The phrase "rods from God" is also used to describe the same concept.[21] An Air Force report called them "hypervelocity rod bundles".[2]

So you're in orbit, which is effectively zero G. What happens when you let go of a thing?

Nothing now you're just orbiting together. Give it a push? Now you've just pushed yourself out of orbit

It cannot hit with the force of a nuclear weapon, but it can be powerful

America doesn't give a shit about treaties.