Looking at it further...
In the case of the system mentioned in the 2003 Air Force report above, a 6.1 m × 0.3 m tungsten cylinder impacting at Mach 10 has a kinetic energy equivalent to approximately 11.5 tons of TNT (or 7.2 tons of dynamite). The mass of such a cylinder is itself greater than 9 tons,
So such a weapon would not only be vastly more expensive, it would be less powerful than the same weight of explosives!
And it's super expensive. I ran the math on this- the cost of 1 tungsten rod and the mass to get it to orbit- not counting the platform to launch it, would cost as much as 10 kilotons (roughly) of GPS-guided JDAM bombs. Thor, by the way, has optimally around 60 tons of TNT equivalent, if I remember.
COURTESY EDIT- Seems I mis-remembered my figures. Assuming $10,000 dollars per JDAM for delivery and pound-for-pound blast equivalence with TNT (Which is not true, I just couldn't find figures, it's probably a lot higher), you could fire off 800 JDAMs for a total of 363 tons of TNT. Thirty times as much as the 10 tons of the Thor, and that's a really conservative estimate.
*If anybody can find me figures for the total cost of a JDAM, including fuel used to transport and deliver the munition, and also the power of the explosive in the JDAM compared to TNT so I can make these figures really accurate, I'd be most appreciative.
That reddit quote is about Project Thor, the US investigation into orbital rod weaponry. You don't realise quite how it seems to lack bang for it's buck: not only is it a lot weaker than you believe, cry, it's monstrously expensive and completely impractical. You don't realise the difficulty of maintaining things in space.
It's not even something you can hide, either: people notice rocket launches. Especially the many, many multiple launches it would take to set up the satellite network to be reliably able to hit targets with the weapon.
It's be easier, cheaper, and more effective to develop ICBMs and use those.
Dropped in the middle of a big city and your take out quite a bit of it plus you just have the. The problem of a giant hole in the city and a 90 ton tungsten rod
It's seeming quite likely you wouldn't even have the giant hole. You'd have a hole, sure, but for the same cost you could have levelled more of the city with bombs.
You think the explosions of a lot of bombs wouldn't shake the earth? It's all about the yield, and the rod just doesn't match up with conventional explosives.
No he said it wasn't a city destroyed
We already established it's not cost effective at all
In that case you just increase the mass until you get destruction needed.
A higher mass exponentially increases the cost involved, due to the Tsiolkovsky rocket equation. Then it'd become even less cost effective the bigger you make it. Getting things into space - to stay - isn't easy.
EDIT: Woops, wrong rocket equation