Rods from God / "Project Thor"

[antigravite]

Hi.

For some whatever reason, a timely article was pu(bli)shed by Sputnik, a Russian media, dealing with an "old" concept of non-nuclear space-based, orbiting kinetic space-to-ground weapon, sometimes described as "Rods from God".

https://sputniknews.com/military/201811091069643510-Project-Thor-Tungsten-Poles-Outer-Space/

This article was reformated and republished (sourced) by spacewar.com or spacedaily.com (same network), gaining hightened visibility.

http://www.spacedaily.com/reports/US_Project_Thor_would_fire_tungsten_poles_at_targets_from_outer_space_999.html

Many information used in this / these article(s) seems to come from the related Wikipedia article:

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

FWIW, "Project Thor" is an old designator:

"Project Thor is an idea for a weapons system that launches telephone pole-sized kinetic projectiles made from tungsten from Earth's orbit to damage targets on the ground. Jerry Pournelle originated the concept while working in operations research at Boeing in the 1950s before becoming a science-fiction writer.[7][8]" (Wikipedia : [7] Jonathan Shainin (10 December 2006). "Rods From God". New York Times. [8] Jerry Pournelle (6 March 2006). "Chaos Manor Mail". The View from Chaos Manor. Archived from the original on 28 August 2008.)

- - - - -

I studied this subject quite a long time ago. There are many open lit patents or patent applications describing this specific concept at large, and in minute details. However, I wonder what's behind Russian authorities masterminds, using friendly media, to bring this subject back in the public-space agenda.

Did I miss something or are Rods from God back from black (magic)?

A.

 

[Orionblamblam]

Hi.

For some whatever reason, a timely article was pu(bli)shed by Sputnik, a Russian media, dealing with an "old" concept of non-nuclear space-based, orbiting kinetic space-to-ground weapon, sometimes described as "Rods from God".

https://sputniknews.com/military/201811091069643510-Project-Thor-Tungsten-Poles-Outer-Space/

The concept is regularly "rediscovered" by magazines and websites and news organizations, just like Pluto and Orion.

However, the comments in that Sputnik piece are amusing, to say the least.

I wonder what's behind Russian authorities masterminds, using friendly media, to bring this subject back in the public-space agenda.

Chances are good that this was just filler, produced when some editor or reporter just happened to stumble across the idea. The other chances are that this is agitprop to gin up fear of Trump/USA for internal political purposes. But most likely the former. It's very unlikely that the USAF is actually planning on fielding such a system or even making noises abut it, because it's an insanely expensive way of making a small hole in the dirt.

 

[antigravite]

Hi. Thx for comments OrionBlamBlam

I heavily edited and will keep updating the preceding post.

Meanwhile doing my homework too, found some interesting stuff… Reddit thread, etc.

Chinese scientists also took an interest in this advanced technology and patented some sort of a similar device as CN106052482B filed on 20160602 but granted on 20171020. The single patent title I found by chance (spent not too much time on it) roughly translates as: "A return to orbit deployment method for space-based kinetic energy weapon strikes area" and is downloadable from here: https://patents.google.com/patent/CN106052482B/en

A.

 

[jsport]

...thought there was international agreement not to use space based DE or KE back down onto the earth surface.

 

[TomS]

The Outer Space treaty prohibits the stationing of weapons of mass destruction in orbit. Whether orbital kinetic kill weapons count as WMDs is an untested question.

 

[Hanse]

The Outer Space treaty prohibits the stationing of weapons of mass destruction in orbit. Whether orbital kinetic kill weapons count as WMDs is an untested question.

Anymore the media considers anything larger than a sparkler a "WMD". : In actuality I don't see how anything aside from nuclear weapons could be considered a "WMD" in the strictest meaning of the term. (Generally anything NBC seems to get "WMD" applied.)

 

[TomS]

The press' overuse of WMD stems from some sloppy lawmaking. The US domestic legal definition of terrorism references the use of WMDs but defines them as any destructive device under the National Firearms Act, which means any device with more than a quarter ounce of explosives.

The US DoD has also added large conventional explosives to its definition of WMD -- CBRNE is the current standard. No specific threshold for explosives to count but I think they generally reckon Khobar Towers or worse.

 

[Orionblamblam]

Chinese scientists also took an interest in this advanced technology ...

No doubt. But physics isn't any different for them than for American scientists. It is certainly possible to launch telephone poles of tungsten into orbit, but the same problems remain. Getting them back *down* is no trivial feat. Unlike how these systems are generally portrayed in the movies (like the second "GI Joe" movie), you don't simply "drop" them. You have to *propel* them down from orbit. And given their great mass, adding a few kilometers per second of delta V to them is no trivial feat.

Additionally, the claims that these things pack the punch of nukes is exaggerated to the point of being outright lies. They would hit the ground at less than orbital velocity (how much less is down to trajectory options... if you slow it down only a little bit to get it to de-orbit, it will hit the ground at a relatively shallow angle; if you drop it straight down, then you had to have dumped most of the orbital velocity). LEO circular orbit velocity is about 7,800 m/sec. The density of tungsten is 19.3 grams/cubic centimeter. So a rod 20 cm in diameter and ten meters long would have a volume of 3.14159*(10^2)*1000 = 314,159 cubic cm => 6,063 kg. Having six metric tons whack you upside the head at 7.8 km/sec would be harsh, but is it nuke-like? The kinetic energy is 1/2 M*V^2 = .5* 6063 * 7800^2 = 184,436,460,000 joules (184.4 gigajoules). One metric ton of TNT releases 4.184 gigajoules, so this six-ton rod has the equivalent yield of 44.1 metric tons of TNT, a multiple of 7.35.

Keep in mind: in order to drop that six ton rod of tungsten on the other guy, you had to expend a de-orbit stage of unknown mass, as well as a whole lot of tons of rocket propellant to boost the system into orbit in the first place. The Falcon 9 Full thrust can put 22.8 tons into orbit (equivalent to 3.75 rods, not counting de-orbit systems...call it three rods), burning through 410.9 tons of propellant in the first stage and 107.5 tons of propellant in the second => 518.4 tons of propellant expended to deliver the equivalent of 3X44.1 tons (132.3 tons) of TNT onto the enemy.

An entire Falcon 9 delivers a maximum of 0.13 kilotons of destructive potential upon the enemy using "Thor." Alternatively, you could load up that Falcon Nine with a couple hundred megatons of thermonuclear sunshine.

 

[Avimimus]

Really nice numbers there. The claims about such a system always confused me. It is nice to see the numbers support why I was confused (i.e. it isn't that impressive an idea).

There is kindof a fascination with kinetic weapons (basically throwing stones - albeit further/higher and larger than usual), tungsten would allow a higher terminal velocity I suppose. The main benefit compared to your 'couple hundred megatons' is, well... considerably reduce fallout? Right? That is a thing?

Also, I suppose one could get more power from the tungsten stick if it was in a highly elliptical orbit, right? If you manufactured it further out in space you wouldn't have to climb the gravity well either. Radioactive decay wouldn't render it inert in a few centuries... so it might have merit if you've got an off-world manufacturing capability and want to have a sword hovering above the world with several centuries or millennia between replacements.

 

[Rickshaw]

The Outer Space treaty prohibits the stationing of weapons of mass destruction in orbit. Whether orbital kinetic kill weapons count as WMDs is an untested question.

Anymore the media considers anything larger than a sparkler a "WMD". : In actuality I don't see how anything aside from nuclear weapons could be considered a "WMD" in the strictest meaning of the term. (Generally anything NBC seems to get "WMD" applied.)

Technically, the term "Weapons of Massed Destruction" applies to chemical, biological, nuclear and radiological weapons. For an excellent description of how the term has been expanded from simple "aerial bombing" to now included the four weapons already mentioned and beyond, I'd recommend the Wikipedia article on "Weapons of Massed Destruction". Like many terms, it has become corrupted in it's meaning by the American mass media which has latched upon it and misused it.

 

[marauder2048]

The US DoD has also added large conventional explosives to its definition of WMD -

I think they dropped that around 2009. The DOD definition has the "capable of a high order of destruction or causing mass casualties"
qualifier which, it has been suggested, is designed to leave open low-yield nuclear weapons.

 

[Orionblamblam]

(i.e. it isn't that impressive an idea).

Actually it *would* be an impressive weapon. Someone on the ground would have very little time to react to it if they detected it at all (if it begins entry-heating to incandescence at 100 km altitude and it's coming in at a shallow angle so it has to cross 200 kilometers and it maintains, say, 7 km/sec, an observer could potentially see it as an incoming glowing spark for about 29 seconds), and even if it was detected there's not a lot that could be done to stop it: hit-to-kill smart rocks would likely just spang off the side of the thing. And when it hit it would make a hell of a mess. Claims of being able to penetrate deeply are generally overblown, but one of these things bullseying a battleship would like to cut it in half.

It's just a terribly *impractical* weapon. The cost is immense, and the tactical utility is poor: how many times in a *day* would the thing be anywhere near the target?

tungsten would allow a higher terminal velocity I suppose.

The high density *and* high temperature would allow a tungsten rod to punch deeper, faster. The drag would be the same as for a rod of the same size and geometry made out of concrete, but the density increase means increased mass but with the same cross-sectional area.

The main benefit compared to your 'couple hundred megatons' is, well... considerably reduce fallout? Right? That is a thing?

A tungsten rod would produce no fallout, since there are no radiologicals involved. Unless it's targeting a nuclear site of some kind.

Also, I suppose one could get more power from the tungsten stick if it was in a highly elliptical orbit, right?

Correct. As well as a more perpendicular strike on the surface, assuming that the de-orbit burn was carried out much further out.

If you manufactured it further out in space you wouldn't have to climb the gravity well either.

In all likelihood, well-developed asteroid mining processes will simply chew up space rocks and separate the resulting fine powders by the elemental compositions (rather than following veins of material through the asteroid, since those are unlikely to exist as such). So metallic asteroids might give you X tons of iron, Y tons of nickel, and Z kilograms of uranium and tungsten in separate bins.

The problem with Thor weapons in deep space is that Thors are meant to take out reasonably precise targets... ships, tanks, bunkers. The likelihood of targeting such systems from beyond the moon is low. Deep-space kinetic bombardment is more likely to take the form of big rocks. Instead of six tons of precisely aimed tungsten you'll get six million tons of meh-aimed metal-rich rock. Put a ten-mile crater in the ground and not only are you reasonably well assured of taking out the target, you also have deniability. "Gee whiz, me? Naw, musta just been one of them Tunguska sort of things. Sad, really..."

 

[zen]

The strength of the concept always struck me as part of the arsenal of weapons available to a space born civilisation.
Getting it down is an interesting issue.

I tend to think an iron rod accelerated by magnetic rail is more reasonable. But the launcher obviously needs to counter the thrust.

Frankly Orion is our only hope in such a situation of an invader. But the 'war' is likely going to be fought way out at Jupiter and the Trojans.

 

[_Del_]

It reportedly got to hardware stage and pummeled the Marshals a few times, so I assume they have good data.

The only advantages are it's it difficult to detect, difficult to deflect/destroy on account of the high mass, it can spend a good deal of time over the (potential) target area in a highly eccentric orbit, and it's absolutely plausibly deniable if you needed a relatively big boom.

The only real use I see is if you secretly stashed a few on highly elliptical orbits say a couple spending most the time over eastern europe/mideast and a couple for asia.. Just waiting for the day you really, really need it and it needs to be deniable. The other advantage of the highly elliptical orbit beyond velocity is that you can spend most of your time over your target. Like a commsat.

It's not exactly cost effective as pointed out. It'd be difficult to work out guidance, particularly for a moving target. And again, it'd be so damn expensive to put up there. So if we had an unlimited budget, sure. Stash a few. Otherwise, it seems firmly in the "nice to have niche" category.

 

[TomS]

Reported by whom? I've never seen a credible claim that orbital bombardment tech was real-world tested or even seriously experimented with.

 

[Orionblamblam]

Reported by whom?

 

[Triton]

Science fiction author Jerry Pournelle wrote on March 6, 2006:

As some of you may know, I "invented" Thor a long time ago. I have no idea who decided to call it "Rods from God", but while I was in operations research back in the 1950's I developed the notion of "orbital telephone poles" made of tungsten, to be coupled with the Thoth Missile guidance systems we were developing at Boeing. Thoth was a ground control system to be used by a forward observer team. As GPS (pretty well put in place by Francis X. Kane, the "silent" co-author of Strategy of Technology, when Kane was at Systems Command) came into play, the Thor concept changed.

Source:
https://web.archive.org/web/20080828221908/http://www.jerrypournelle.com/archives2/archives2mail/mail404.html#Thor

 

[_Del_]

From memory (take it for what it is worth):
The Marshall tests were well after Thor, stemming from related projects in the late 70's, early 80's. I want to say '82 with the project cancelled around 84. Had some relatively common maths. Also where I first realized the HEO with the commsat orbits spending most their time over an operational area (something I already knew) is another benefit in the context of orbital bombardment.

I pretty sure I found it in a DTIC search for ERIS information. It had a relatively short segment devoted to orbital bombardment among the SDI info. It was news to me; I'm not claiming any first-hand knowledge.

Tried to see if I could find anything today and have struck out so far. Might be a weekend project.

 

[Orionblamblam]

I would suggest you're probably conflating Thor with some bog-standard MIRV tests, such as shown here starting at the 0:48 or so mark:

View: https://youtu.be/PDL_pIPScSI?t=48


If you saw the MIRVs coming in and didn't know what they were, even if they had inert warheads it'd look a lot like what a Thor Might look like (though Thor would probably be noticeably faster).

 

[Hanse]

I would suggest you're probably conflating Thor with some bog-standard MIRV tests, such as shown here starting at the 0:48 or so mark:

https://youtu.be/PDL_pIPScSI?t=48

If you saw the MIRVs coming in and didn't know what they were, even if they had inert warheads it'd look a lot like what a Thor Might look like (though Thor would probably be noticeably faster).

Mix in some testing Sandia supposedly did in support of the Pershing II penetrating nuke, firing RVs into solid granite mountains, and having them survive. . .

 

[kcran567]

Really nice numbers there. The claims about such a system always confused me. It is nice to see the numbers support why I was confused (i.e. it isn't that impressive an idea).

There is kindof a fascination with kinetic weapons (basically throwing stones - albeit further/higher and larger than usual), tungsten would allow a higher terminal velocity I suppose. The main benefit compared to your 'couple hundred megatons' is, well... considerably reduce fallout? Right? That is a thing?

Also, I suppose one could get more power from the tungsten stick if it was in a highly elliptical orbit, right? If you manufactured it further out in space you wouldn't have to climb the gravity well either. Radioactive decay wouldn't render it inert in a few centuries... so it might have merit if you've got an off-world manufacturing capability and want to have a sword hovering above the world with several centuries or millennia between replacements.

The ultimate rock throw would be controlling (adding some type of propulsion and guidance) to space rocks/asteroids the bigger the better. Mountain sized. And then parking it over the enemy whoever that would be. Could destroy an entire continent if possible? But also start an ice age for the entire planet?

 

[Orionblamblam]

The ultimate rock throw would be controlling (adding some type of propulsion and guidance) to space rocks/asteroids the bigger the better. Mountain sized. And then parking it over the enemy whoever that would be. Could destroy an entire continent if possible? But also start an ice age for the entire planet?

The point of dropping rocks on people is deniability. Rocks fall on their own, perfectly naturally, as Tunguska and Chelyabinsk showed. If you are going to park a rock in orbit and use it as a threat, you'd be better advised to simply invest in Really Powerful H-bombs in the gigaton range. Because de-orbiting a mountain to drop in within half a hemisphere of the target would be a monumental challenge, and you wouldn't be fooling anyone.

That said: parking a mountain in high orbit is *good* idea. But to chew it up for resources, rather than as a hammer. You could always mount mass drivers to it to chuck ten-ton bricks of asteroidal nickel/iron at anyone who ticks you off.

 

[_Del_]

I would suggest you're probably conflating Thor with some bog-standard MIRV tests, such as shown here starting at the 0:48 or so mark:

View: https://youtu.be/PDL_pIPScSI?t=48


If you saw the MIRVs coming in and didn't know what they were, even if they had inert warheads it'd look a lot like what a Thor Might look like (though Thor would probably be noticeably faster).

Sorry if I was not clear. This wasn't something I saw. It was something I read on a mostly SDI-Rrelated doc I found on DTIC. Wasn't able to rediscover the same doc yesterday, but the post recounts the content I read, as I remember it.

 

[Byeman]

Also where I first realized the HEO with the commsat orbits spending most their time over an operational area (something I already knew) is another benefit in the context of orbital bombardment.

Physics don't make that work. Any thrust to deorbit an object in a geostationary orbit is also going to make it move out of sight from the target. Technically, deorbiting from GSO (with the minimum propellant) is going to put the object 90-180 degrees away from the original stationary point.

Look at the diagram below. This is what entry from HEO (GSO) would be like.

 

[_Del_]

Also where I first realized the HEO with the commsat orbits spending most their time over an operational area (something I already knew) is another benefit in the context of orbital bombardment.

Physics don't make that work. Any thrust to deorbit an object in a geostationary orbit is also going to make it move out of sight from the target. Technically, deorbiting from GSO (with the minimum propellant) is going to put the object 90-180 degrees away from the original stationary point.

Look at the diagram below. This is what entry from HEO (GSO) would be like.

HEO is Highly-Eccentric orbit. A geostationary orbit has zero eccentricity...


ETA: I also do not see why you couldn't deorbit from GSO into a stable HEO and then deorbit orbit over the same location you held GSO over on the next pass (even though absolutely noone is suggesting that because it involves a lot more fuel than deorbiting while approaching a higher apogee, lower velocity in a HEO).

 

[NUSNA_Moebius]

The ultimate rock throw would be controlling (adding some type of propulsion and guidance) to space rocks/asteroids the bigger the better. Mountain sized. And then parking it over the enemy whoever that would be. Could destroy an entire continent if possible? But also start an ice age for the entire planet?

The point of dropping rocks on people is deniability. Rocks fall on their own, perfectly naturally, as Tunguska and Chelyabinsk showed. If you are going to park a rock in orbit and use it as a threat, you'd be better advised to simply invest in Really Powerful H-bombs in the gigaton range. Because de-orbiting a mountain to drop in within half a hemisphere of the target would be a monumental challenge, and you wouldn't be fooling anyone.

That said: parking a mountain in high orbit is *good* idea. But to chew it up for resources, rather than as a hammer. You could always mount mass drivers to it to chuck ten-ton bricks of asteroidal nickel/iron at anyone who ticks you off.

Chew it up for resources, then use it as a hammer, Gundam Universal Century style (because nuclear weapons were banned under treaty).

Colony dropping makes for snazzy times too B)

 

[kcran567]

The ultimate rock throw would be controlling (adding some type of propulsion and guidance) to space rocks/asteroids the bigger the better. Mountain sized. And then parking it over the enemy whoever that would be. Could destroy an entire continent if possible? But also start an ice age for the entire planet?

The point of dropping rocks on people is deniability. Rocks fall on their own, perfectly naturally, as Tunguska and Chelyabinsk showed. If you are going to park a rock in orbit and use it as a threat, you'd be better advised to simply invest in Really Powerful H-bombs in the gigaton range. Because de-orbiting a mountain to drop in within half a hemisphere of the target would be a monumental challenge, and you wouldn't be fooling anyone.

That said: parking a mountain in high orbit is *good* idea. But to chew it up for resources, rather than as a hammer. You could always mount mass drivers to it to chuck ten-ton bricks of asteroidal nickel/iron at anyone who ticks you off.

If the current trends continue and the world becomes more and more multipolar, can envision a future arms race where say China becomes the first nation to capture and mine a very large space rock and also uses it as a deterrent, so a dual use. We really want to use this for economic reasons but please don't try and get out of line or it might fall in you're hemishere!

 

[martinbayer]

Interesting thought. If that were indeed to happen at some point, warfare would have gone full circle all the way back to its rock throwing origins again...

Martin

 

[Byeman]

HEO is Highly-Eccentric orbit. A geostationary orbit has zero eccentricity...

HEO is High Energy Orbit.

ETA: I also do not see why you couldn't deorbit from GSO into a stable HEO and then deorbit orbit over the same location you held GSO over on the next pass (even though absolutely noone is suggesting that because it involves a lot more fuel than deorbiting while approaching a higher apogee, lower velocity in a HEO).

There is no such thing as a " stable HEO" (either definition) when it comes to ground tracks. Any orbit other than GSO means the ground track is going to move. Even deorbiting from the apogee of a Highly-Eccentric orbit means the entry is going to be 90-180 degrees away from the target.

 

[Orionblamblam]

HEO is Highly-Eccentric orbit. A geostationary orbit has zero eccentricity...

HEO is High Energy Orbit.

But wait! There's more!

High Earth orbit - Wikipedia

en.wikipedia.org

View: https://www.youtube.com/watch?v=-WdlrqDIsgA

 

[Charlesferdinand]

Would these tungsten rods lose a lot of their mass through friction by the atmosphere. What are the chances that they break up before they hit the ground.

Also, why rods? Obviously it looks cooler, but ouldn't balls be more convenient and ballistically more effective?

 

[Orionblamblam]

Would these tungsten rods lose a lot of their mass through friction by the atmosphere.

Not if designed correctly. The nose would probably have an ablative cap.

Also, why rods? Obviously it looks cooler, but ouldn't balls be more convenient and ballistically more effective?

Nope. The point is to retain as much velocity as possible, to lose as little of it as possible due to drag. And one simplistic way to look at the drag of ballistic objects is the mass per cross sectional area. So... look at a tungsten rod shaped like a pencil. Each square inch of frontal area might be backed up by ten, fifteen, twenty *feet* of tungsten. A sphere of the same mass would be considerably larger in diameter, with much less mass per cross sectional area. This is related to why bullets these days are relatively long compared to their diameter... and not musketballs.

 

[LowObservable]

Also, when a long rod strikes a solid object, its kinetic energy is concentrated on a small area. Think of an APFSDS tank gun round.

 

[Charlesferdinand]

Also, when a long rod strikes a solid object, its kinetic energy is concentrated on a small area. Think of an APFSDS tank gun round.

Agreed, but that would depend on the accuracy you can expect. So would these projectiles have some kind of steering mechanism, and be something like a guided bomb?

 

[Orionblamblam]

So would these projectiles have some kind of steering mechanism, and be something like a guided bomb?

Yes. Exact mechanisms of both navigation and maneuver is unclear, but presumably they'd be able to get occasional GPS fixes. Given their velocity at the end, it's unlikely that they'd really be up-to-the-microsecond, but they should follow pretty predictable paths. Likely use paddles at the tail for pitch and yaw.

 

[Brickmuppet]

.........

Additionally, the claims that these things pack the punch of nukes is exaggerated to the point of being outright lies. They would hit the ground at less than orbital velocity (how much less is down to trajectory options... if you slow it down only a little bit to get it to de-orbit, it will hit the ground at a relatively shallow angle; if you drop it straight down, then you had to have dumped most of the orbital velocity). LEO circular orbit velocity is about 7,800 m/sec. The density of tungsten is 19.3 grams/cubic centimeter. So a rod 20 cm in diameter and ten meters long would have a volume of 3.14159*(10^2)*1000 = 314,159 cubic cm => 6,063 kg. Having six metric tons whack you upside the head at 7.8 km/sec would be harsh, but is it nuke-like? The kinetic energy is 1/2 M*V^2 = .5* 6063 * 7800^2 = 184,436,460,000 joules (184.4 gigajoules). One metric ton of TNT releases 4.184 gigajoules, so this six-ton rod has the equivalent yield of 44.1 metric tons of TNT, a multiple of 7.35.

Keep in mind: in order to drop that six ton rod of tungsten on the other guy, you had to expend a de-orbit stage of unknown mass, as well as a whole lot of tons of rocket propellant to boost the system into orbit in the first place. The Falcon 9 Full thrust can put 22.8 tons into orbit (equivalent to 3.75 rods, not counting de-orbit systems...call it three rods), burning through 410.9 tons of propellant in the first stage and 107.5 tons of propellant in the second => 518.4 tons of propellant expended to deliver the equivalent of 3X44.1 tons (132.3 tons) of TNT onto the enemy.

An entire Falcon 9 delivers a maximum of 0.13 kilotons of destructive potential upon the enemy using "Thor." Alternatively, you could load up that Falcon Nine with a couple hundred megatons of thermonuclear sunshine.

Davy Crocket's W-54 warhead had a yield of either 10 or 20 tons depending on setting so 44T is technically in tactical nuke territory. However, the W-54 got most of its lethality from the radiation pulse, so the Thor, even given double the blast, is probably less effective. It's probably more deliverable in a high threat environment than a BLU-82(Daisy Cutter) though.

The concept as a whole, associated with something like a re-useable Falcon might give us some idea of what the Chinese interest (mentioned earlier in the thread) might be looking at. Take Mr. Lowther's six ton tungsten rod and increase it by 50% for 9 tons (this is a completely arbitrary figure intended to allow for something small but with a thrust to weight ratio akin to a SPRINT ABM motor) This weapon needs targeting, quite precise targeting given the guidance challenges during re-entry, so we'll be insanely generous and provide each weapon system with a KH-11 spy satellite= about 12 tons. This is certainly on the high end of targeting needs and budgeting possibilities but it allows us some design margin.

Falcon Heavy can throw 63 tons into low earth orbit. 63-12=51 which leaves 51 tons remaining.
51 tons divided by 9 tons per tungsten telephone pole+de-orbit motor in turn yields 5.667.
This gives us 5 warshots and .667 of 9 tons to add to our design margin.
So we have 5 warshots per launch to LEO.
However, an on call orbital system probably ought to be in Polar, Molniya or SSO orbit so we'll go with 2 shots per launch as an alternative, low end case.

The goal for Falcon Heavy is reportedly 100 launches. One can assume a Chinese equivalent will be similar so 100 launchers give 10 thousand launches which result in 20,000 or 50,000 warshots on station depending on the orbit chosen. In a polar orbit the whole enchilada could be fired at one target in a 24 hour period. Optimistically assuming a firing window of one half hour for each satellite, about 213 shots would be in position over any point on Earth at any time. Optimistically assuming a launch a week per rocket, the USSF or the People's Liberation Army Taikonaut Attack Corps (?) could put this sword of Damocles up in two years or so.

Each shot is, again, equivalent to 2 and a half Daisy Cutters. Any warship, even A Nimitz or Kuzenetsov class, will be ended by a hit from one of these things. Even the lower end figure of 20,000 is a much greater number than there are warships in the world. Sink any one navy and there are enough left over to use against most fixed targets of strategic importance such as RailYards, power plants, Whata-Burgers, air fields, dams, canal locks, munitions factories, command/control centers and even strategically located cloverleafs.

100 rockets, 10,000 launches and their not inexpensive payloads are a massive and, arguably, unrealistic investment but by no means an impossible one. Given the current downward trends in launch costs facilitated by Mr. Musk, the cost to benefit analysis of this sort of thing with regards to national goals and resources is going to trend in its favor in the future.

Full disclosure: I'm a History Major, not an engineer, so I grimly await having my math checked.

 

[Orionblamblam]

The goal for Falcon Heavy is reportedly 100 launches. One can assume a Chinese equivalent will be similar so 100 launchers give 10 thousand launches which result in 20,000 or 50,000 warshots on station depending on the orbit chosen. In a polar orbit the whole enchilada could be fired at one target in a 24 hour period. Optimistically assuming a firing window of one half hour for each satellite, about 213 shots would be in position over any point on Earth at any time. Optimistically assuming a launch a week per rocket, the USSF or the People's Liberation Army Taikonaut Attack Corps (?) could put this sword of Damocles up in two years or so.

While I'm sure we can all agree that a launch a week for two years of a F9H class booster carrying USSF payloads would be a laudable goal, it would pretty much necessarily cause an arms race... which might or might not be a good thing. As with any satellite, there are chances of something going screwy and the thing falling out of orbit. Usually a satellite coming down results in harmless things like burnt bits of tank landing in the outback or Soviet fissionables scattered across a grateful Canadian tundra, but having tungsten telephone poles belly flopping out of the wild blue yonder could make for some entertaining CNN Personally I think it'd be worth the risk *if* those rods have white stars painted on the side... but if it's a red star, that's not so good.

Launching a *few* of these into orbit makes for an interesting tactical weapon. If the US and China tangle over, say, a Chinese invasion of the Spratleys or Japan, and one side or the other sinks a ship or two with a rod or two... things *may* stay conventional. but if one side has thousands of rounds overhead, they cease to be tactical weapons and become strategic. China sinks an American carrier with one of these from there vast orbital stockpile, chances are fair that the US Navy will respond not with some F-18's dropping JDAMs, but with an Ohio launching a barrage of Tridential howdies.

Any warship, even A Nimitz or Kuzenetsov class, will be ended by a hit from one of these things.

That might not actually be true. Yes, it seems entirely plausible that getting bullseyed by a rod would result in the rod going straight through the ship... but would it necessarily sink it? Sure, having a hole a yard wide punched suddenly through the middle of your ship is in no sense a good thing, but ships have watertight compartment doors for a reason. Unless the ship *completely* stops the round, then the 44 isotons of yield is to some degree simply wasted. The water below the ship will eventually stop the round, converting its kinetic energy into thermal and generating either a big bubble of steam or a long string of such. Exactly how fast the water stops the round will determine if the ship has to deal with a giant bubble underneath it, lifting the vessel out of the water and snapping its keel, or if the ship will just find itself sailing through a sea of seltzer for a few seconds.

 

[Brickmuppet]

Any warship, even A Nimitz or Kuzenetsov class, will be ended by a hit from one of these things.

That might not actually be true. Yes, it seems entirely plausible that getting bullseyed by a rod would result in the rod going straight through the ship... but would it necessarily sink it? Sure, having a hole a yard wide punched suddenly through the middle of your ship is in no sense a good thing, but ships have watertight compartment doors for a reason. Unless the ship *completely* stops the round, then the 44 isotons of yield is to some degree simply wasted. The water below the ship will eventually stop the round, converting its kinetic energy into thermal and generating either a big bubble of steam or a long string of such. Exactly how fast the water stops the round will determine if the ship has to deal with a giant bubble underneath it, lifting the vessel out of the water and snapping its keel, or if the ship will just find itself sailing through a sea of seltzer for a few seconds.

I'd think that the heat would generate a steam bubble breaking the ship's keel, but as you say some testing would be needed to determine if this is in fact the case. Interestingly, the effect you mention might make these things much more lethal in shallow water.

I wonder if a shrapnel round would be practical?

With regard to maintenance issues and satellites tumbling out of orbit, we'll be pessimistic and assume each satellite needs maintenance once a year. In both scenarios above there are 10000 orbital platforms. Divide that by 350 rather than 365 to allow 15 days of leeway per year. That's 28.5 so an orbiting maintenance station would have to go service 29-30 satellites a day. Assume 5 such stations that goes down to 6 and if you have 2 servicing cradles per station you are doing 3 satellites per work area per day which is an 8 hour shift per satellite. Extend the life of the satellites to anything close to that of a KH-11 and you really only need one maintenance platform to keep these things from falling without permission. The maintenance station is vulnerable of course and if the balloon went up any crew would probably have bail out real quick, but having it crewed allows for hands on maintenance and programing during peacetime without relying on remote communications so it MIGHT be less susceptible to hacking in some scenarios.

Also it'd give space force personnel something to do in space.

 

[Orionblamblam]

I wonder if a shrapnel round would be practical?

The purpose of a log made out of tungsten is to punch *deep,* bunker busting and the like. If you want to kill a ship, what you probably want is a round that blows upright around contact. These things would be moving so fast that any bursting system short of an embedded nuke would turn them not into a nice spherical explosion, but sort of a shotgun blast.

But if you have "bursting rounds," they take the place of "bunker busters." More options, but less of what the system is supposed to be best at.

With regard to maintenance issues and satellites tumbling out of orbit, we'll be pessimistic and assume each satellite needs maintenance once a year.

We'll also be realistic and recognize that sometimes boosters and upper stages don't put their payloads in quite the right orbits. A Thor system should be relatively dense compared to other satellites, even considering associated telescopes, antenna and solar panels, so if it is in the right orbit it should deviate much more slowly due to drag.

 

[LowObservable]

I have heard it theorized, by someone I would regard as an expert, that a shotgun blast on the right scale is exactly what you need against a warship.

It would not sink it but it would trash almost every sensor/comms aperture on board.