The weapons system “Rods from God” is being made possible by Elon Musk and breakthrough engineering technologies created as part of SpaceX. In the 1950s, the idea of a space weapon system known as Thor was thought up. It consisted of Tungsten rods, about a foot in diameter and 20 feet long. It contains a guidance system and a way to launch the projectile from orbit to a precise location on Earth. Over time, the name was changed to Rods from God. A rod from god would kinetically deliver energy to a target equivalent to roughly 11 tons of TNT. It would be extremely difficult to defend against. It could attack surface targets with extreme precision, by some estimates, about 15 minutes from launch.
Rods from God has the potential to offer a much cheaper and more usable alternative to nuclear weapons. It could be the 21st-century equivalent of the 19th-century warship used for gunboat diplomacy.
The concept has been investigated by the Department of Defense several times over the last 60 years. The nextbigfuture.com, by Brian Wang, reconsidered the concept in 2018 with a look at possible cost reductions by SpaceX. Wang noted the major impediment to implementing such a weapon is the cost of taking it to orbit. Another major problem is ensuring a precise guidance system.
SpaceX, with its reusable Super Heavy Booster and Starship, along with Starlink, has the potential to solve both problems. The initial rod from god (Thor) weapon was projected at a mass of 8,000 kilograms, about 17,000 lbs. SpaceX and Starship are projected to reduce cost to orbit to $12 to $17 per pound.
With SpaceX, the cost of orbiting rods from god are reduced from hundreds of millions of dollars per rod in the 1960’s to hundreds of thousands of dollars in a few years. This is based on a reduction of the cost of launching a pound into orbit from $5,000 twenty years ago, to $800 now, to about $10 in ten years with mass production of the reusable Super Heavy Booster and Starship.
This compares favorably with weapon systems such as the patriot missile system, which costs about $4 million per missile.
The two weapons systems have different functions. A Rod from God system is extremely hard to defend against. No fixed earth bound system, fortification, large surface ship, or concentration of troops would be immune, anywhere on the planet.
With the Starlink system, the guidance problem is overcome. The fifth Spaceship test flight demonstrated how the Starship kept telemetry through a very hot re-entry. Communication with an orbiting system above you is much easier than sensing a target below you. A constellation of thousands of orbiting satellites (Starlink) tracking your progress and making corrections is very difficult to block.
An alternative method has been demonstrated by Sandia labs, with reasonable potential for a super accurate, cheap, small inertial guidance system. It does not depend on communications. It is just coming out of the laboratory stage.
It is plausible that such a system would not have to depend on kinetic energy. It could also deliver thousands of miniaturized drones anywhere in the world, using ablative materials, steel tubing, and perhaps parachutes to decelerate. Picture a drone the size of a hummingbird with a range of a few miles. Thousands of them linked together to a constellation of satellites, each one capable of disabling a human without killing them.
Control of low Earth orbit gives control of Earth if power can be brought to bear. Rods from God, miniature drone swarms, and potentially directed energy weapons make such control a serious possibility.
Radically decreasing the cost to orbit makes all this possible. Elon Musk is 90% of the way there with SpaceX. Such systems have the potential to make defense of America’s borders cheap because large troop masses or ships would be fairly easy to attack and destroy. Rods from God systems are more precise than nuclear weapons, without radioactive fallout. They have the potential to be much cheaper to build and maintain. With Elon as co-chair of the Department of Government Efficiency, it seems likely the Trump administration will be looking at the Rods from God concept.
Conventional, large-scale invasions become extremely difficult while borders are guarded by a Rod from God defense. Asymmetrical warfare becomes more attractive, just as it has with has nuclear weapons. Infiltrating individual soldiers across borders becomes a useful tactic. Militias become more useful as a dispersed defense. Weapons that can be concealed on an individual become more useful. China’s strategy of “capturing the elite” is unaffected. From cepa.org:
China’s ability to capture elites is a particular and distinctive threat. The party-state’s long-term, patient, and sophisticated strategy of exploiting the opportunities presented by globalization has led to many individuals, organizations, and corporations having stakes in good relations with China. An important subset of these stakeholders acts and speaks (or refrains from words and deeds) in ways that prioritize Chinese interests over their own countries’ national security. The wider effect of this is collective self-censorship and self-restraint amounting to self-harm: our response fails.
Cheap access to orbit gives the United States a distinct strategic advantage if we seize it. Elon Musk estimates the Chinese are 10 years behind SpaceX at this point. If they seize control of space before us, the advantages become theirs.
About Dean Weingarten:
Dean Weingarten has been a peace officer, a military officer, was on the University of Wisconsin Pistol Team for four years, and was first certified to teach firearms safety in 1973. He taught the Arizona concealed carry course for fifteen years until the goal of Constitutional Carry was attained. He has degrees in meteorology and mining engineering, and retired from the Department of Defense after a 30 year career in Army Research, Development, Testing, and Evaluation.
The problem with the “Rods from God” is that their kinetic energy yield is no better than a large conventional bomb. To get nuclear level yields, the rods need to be double or triple the mass and must be traveling close to 100,000 miles per hour. I’ve done the math for one of my books. They’d need to be boosted from a geosynchronous orbit and after the engines quit, continue to drop, accelerating after the burn at 9.8 m/sec. They would need to start about half way to the moon to get a nuclear yield. Other than that…
But you don’t need a “nuclear” yield — that’s the point! Megaton weapons were purely political hype. Even kiloton weapons are wasteful and were developed around assumptions about mid-20th century accuracy then later about early 21st century interception rates. Kinetic weapons don’t need a massive area of total destruction if they can achieve the accuracy to hit the specific target. A 10kt nuke only needs to get within about 1 mile of its target to destroy anything that isn’t a deeply buried and shielded bunker. A single ‘Rod from God’ weapon gives 1/1000th that much power but it will still… Read more »
Hmmm…
Sounds like “Footfall” an SF novel from Niven and Pournelle.
Well, since Pournelle came up with the concept in the 1950s, I guess he had to work it into a novel somehow….
The human race is self-defeating. If we can’t eliminate each other with traditional war, we can do it with war-focused economic projects.
HLB