:smack: Sorry…I didn’t see it. I’m glad you enjoy his channel…it’s one of my favorites. 
I watched a couple of Children of a Dead Earth videos. While the orbital mechanics stuff was neat, I didn’t think it was particularly realistic:
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Combat distance seemed very close. I would expect ranges of thousands of km, not a dozen km. If you can see a ship and can plot its orbital path, there’s no reason you can’t shoot thousands of rounds on an intercept course for it to fly though.
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As I mentioned, nukes don’t make great weapons in space. At least, not like they do on Earth. On Earth, most of the destructive power comes from the shockwave. No shockwave in space.
It is really good. Not just the stuff on space warfare. A lot of interesting stuff on AI, megastructure, interstellar and galactic civilizations, space travel and so on.
Fair points. I think these are compromises to making a game that is both interesting to play and feasible to make. E.g. short range lasers or mass drivers require the player to set up an intercept so they get close enough to their target, which turns the game into a sort of orbital mechanics puzzle. Plus, such weapons are easy to simulate, while it’s not really feasible to simulate sophisticated AI guidance on swarms of missiles, or ECM/ECCM duels that occur on a scale of milliseconds.
As a longtime reader of Science Fiction, I always imagine it to be very similar to a sea battle in the days of sailing ships. (I also read O’Brian.)
Although detonating a nuclear weapon in a vacuum won’t produce the thermal pulse or shockwave that it does when X-rays are absorbed in an atmosphere, it is possible to have a sacrifical material built into the weapon that is opaque to radiation such as compressed polystyrene to convert the high frequency radiation into kinetic energy, and even be designed to create a directional blast by containing the expanding cloud of material or selectively controlling the absorption of X-rays. Although the initial plasma cloud may be focused, it would diverge over distance, so it would have to be relatively close.
It is also possible to design a boosted fission design which produces a large portion of the energetic yield in neutrons, which when interacting with a target will activate fissile materials and cause fissionable materials to fast fission so that any reactors, weapons, or shielding which contain these materials become a hazard. However, the neutron output is essentially omnidirectional and the flux will drop off as a square of distance, so again to have a significant effect it would need to be very close or extremely large.
At any rate, nuclear weapons are expensive to manufacture and require fissile materials that are difficult to find and extract. Balls or rods made of iron or nickel—both materials which are found in asteroids in significant quantities—are comparatively cheap to produce, and a wide field of projectiles moving at tens of kilometers per second would be difficult to see coming or avoid, and essentially impossible to defend against.
Stranger
Make it 2160 and I would not have so many issues with it. 40 years for heavy orbitals and colonizing Mars enough so that it does not require outside resupply enough to be uppity with Earth. I’m about as Free Mars as the next guy, between B5 and the Expanse but your running into a materials science problem for no good reason.
Patriots and MLRS are good enough and already come with their own box launchers, you only need to add the vernier jets for directional control and presumably by 2060 thats already going to be a feature. Solar sail, not needed and will take up space and your going with an orion instead of a nirva drive, so all the nukes are going out the wrong end to a big ass pusher plate whose single point failure is the return springs.
The best your going to get is an armed merchant ship in the time you postulate, a dedicated warship is a waste of money. Better top use canister for a whiff of the grape and then close with and board with marines, and on the other side, fortify strong points and stay behind a wall of mines.
The biggest problem is that any industrial base is a sitting duck - mars, earth, moon, or a big asteroid. You could conceivably bury it -but you still have to collect resources. How may tons - how many million tons - of uranium ore do you need to collect to purify enough fissible uranium to make enough bombs to maneuver dozens or hundreds of Orion-class craft? Those mines, that logistics and supply trail will also be vulnerable. Can you harden an entire society? Probably not in 50 years considering today lofting 6 people up to low earth orbit is a major investment. I agree, make it 2160. The suggestion was that each side in the cold war had about 20,000 bombs over about 40 years. How many bombs to fly a small craft from Earth to Mars? Plus, enough shielding to protect the occupants from solar flares and nearby neutron bombs would make a craft unweildly heavy.
BTW - those spring-loaded shields will still need to shed heat - not all the explosive power is impulse.
I think the best solution is some form of nuclear engine as originally envisioned, a pile that creates a huge jet of superheated propellant. Or, simple hydrogen-oxygen engines. All that’s needed is a supply of water and electricity, which is more plentiful up there than uranium, I bet. I imagine a ship that inflates (see Bigelow Aerospace) for living space and folds up tiny except for a small crew pod for high-speed combat.
The solution to protecting cities from bombing was to have dominance of the air. Followed by anti-aircraft missiles; followed by stealth aircraft and drones (or cruise missiles) to take out AA batteries. Then there were missies; followed by anti-missile missiles. Followed by attack in volume so you can’t guarantee all of them are stopped. MIRV - Multiple Independent-targeted Re-entry Vehicle - yes, was for missiles on re-entry to attack multiple targets. However, the concept is the same in space - one launcher takes a bus with multiple warheads close to the target, then the individual warheads scatter and take evasive maneuvers to follow the target(s); same concept as with the cold war - too many at once to guarantee none get through. Throw in a number of “dummy” warheads that appear to be real but simply waste the resources of the defender.
And then there’s stealth - a small canister - equivalent of suitcase nuke - could be launched in a orbit to arrive much later from a random direction; or sent far away to approach from a different track. How easy is it to spot something like that if suitably stealthed? How do you protect against that?
And still nobody has acknowledged the problem of kinetic debris. Any use of kinetic weapons, or something that leaves debris, is something that poisons that orbit for millennia to come unless it’s low earth orbit - then you just poison space travel for decades or centuries.
If your coming out of the Earth gravity well, then debris is a problem to solve. But really that only means that you either slow it down, or maneuver something into the oncoming path to soak it up. Its a problem for us now, for us in the future with that engineering tech base, then thats what garbage scows and scavengers are gonna be for.
Anything in space is going to be a commodity, so a broken ship is going to get salvaged really quickly and repurposed. Kinetic rounds, known vector and distance is equal to speed over distance. Issue a NOTAM for that vector of space and let it grandfather when the rounds exceed expected distance.
As long as it’s not a shotgun scattering of huge number of ball bearings relying on relative velocity; and of course, fragments of an exploded device or damaged ship could fly off in unpredictable directions. If you annihilate an enemy vessel, presumably you also annihilate all records of his weapons deployed - except for those you encounter… Take a lesson from today’s landmines. Despite the obvious danger, we have several theatres of war where sufficiently detailed knowledge of the location of mines is lost.
Debris created in Earth’s gravity well (or any other close orbit) is a worse problem, because what goes around comes around - literally! - in a month or less, possibly in an hour and a half. It can take decades to decay out of orbit, and only if the body it orbits has an atmosphere.
Plus, the exact track of any weapon launched could be less precise with time - you cannot know the precise course a year later - a tiny uncertainty of direction or speed can make a huge difference. .Add to that that many of the weapons you may be trying to “sweep up” are deliberately stealthed, and the challenge is even greater.
This isn’t such a terrible problem on an asteroid as you might think. On a typical asteroid, most bullets would be going fast enough to reach escape velocity. Even on a large asteroid such as Ceres or Vesta, high velocity bullets would escape and be lost. And low velocity bullets would have long orbital periods, which should give you enough time to track and catch them. If you want to have a war on an asteroid, either use high velocity bullets or be prepared to be hit in the back by your own ordnance a couple of hours later.
But that’s precisely the problem. High-velocity bullets will now pollute the neighbourhood (and further as time goes on). The further out from Ceres you get, the more likely the strike will be higher velocity, since your spaceship will be travelling much faster relative to the source than in the immediate neighborhood of the asteroid. When you fire off hundreds of thousands of rounds, the odds of a strike go up astronomically (so to speak).
Which brings us back to the problem of detecting and collecting tiny debris the size of bullets or ball bearings…
I suppose an interesting option would be ice pellets with embedded carbon particles or such, so that they will over time evaporate (sublime?).
I don’t mean to hijack, but I seem to recall a science fiction story I read when I was young that had the characters use pistols (real, propellant-based cartridges with heavy frangible bullets) to maneuver in space. The space suits had thrusters, of course, but the thrusters were saved for delicate maneuvers. If a character wanted to go in a certain direction, a shot was fired in the opposite direction. The velocity gained was small, but effective.
It wasn’t discussed in great detail. The narrator pointed out that cartridges were low-tech, but small, self-contained, and easily reloaded. It was also stated that the chances of the bullets (which were frangible) ever actually endangering anything were almost non-existent because space is so “damn big.”
Go play with a laser calculator. Ultimately, lasers are the king of the battle because you can achieve greater range than basically anything else. In principle, using X-ray lasers and a kilometer or so sized focusing lens, you could hit targets on earth from Mars.
Though, particle beams (C-beams, the reason they glitter is because some of the particles are cooling to ground state and emitting photons as they hurtle through space) are another way. Keep in mind that they must be neutral particle beams. It’s 2 particle accelerators in your warship, one accelerates electrons, the other protons, and then they get recombined right at the muzzle.
Unfortunately there are a lot of problems with beam divergence, and this type of weapon is thought to have a shorter effective range than a laser - but dramatically more damage potential. When they hit the enemy ship the particles will become X-rays and disrupt electronics and crew.
Missiles aren’t going to be effective if the enemy can just kill their engines with a quick burst of fire from a defensive laser or particle beam. Same story with railgun rounds - if the enemy laser boat can get enough beam concentration on your warship from 10,000 kilometers away, you’ll get burned out of space before you ever get into range to use the railgun.
There is a range limit because of how far an enemy warship could random walk over the flight time of a railgun shell only traveling at 20 or so kps.
No cover, no stealth. Whoever has more range wins.
One comment is that in a situation like this, where both sides have sophisticated computers and modeling tools, nobody is going to start a fight they don’t think they can win. It’s going to be a constant game of bluffing and estimating of the other’s capabilities.
Guided railgun rounds would have dramatically more range, but as they emit puffs of hot gas to correct course, they would be visible and vulnerable to defensive fire from defensive lasers/railguns/particle beams on the opposing warship. Also keep in mind that railgun rounds will be glowing red hot from their brief role as a current conductor in the gun itself. So trivially easy to track on the defending side, and thus evade. (unless the range is so short there’s no time)
I think low orbit slugmatches might be more interesting because of the very short horizon might allow for some level of surprise and immediate firepower would be more important.
I wouldn’t worry too much about the bullets that reach escape velocity. Once they are out in the asteroid belt, they’ll get lost among all the other pebble-sized rocks out there. There are countless quintillions of pebbles in the Solar System- a few million bullets won’t cause much of a hazard. They will be slightly dangerous one Cerean year after they are first fired, because they’ll come back to somewhere near Ceres in their orbit- but they’ll soon drift away because of Yarkovsky effect and other perturbations.
Although orbital debris around a planet is a genuine problem because satellites pass through the same volume of space periodically, in interplanetary space the odds that another vessel will randomly cross into the path of a projectile that isn’t aimed at it is very, very low. The potential still exists, but consider as an example that the Earth occupies 0.0009% of the volume its orbit. so if you fired a projectile in a random direction crossing Earth orbit at roughly the same speed as the Earth. When you look at something spacecraft size, e.g. five or six orders of magnitude smaller than the Earth, the potential to be damaged by a random projectile is far less than many other more likely risks. Which is a good thing because nature has provided a vast number of natural projectiles which will be equally impossible to see or dodge.
If there are space fights in near orbital space of large planets that may become a more significant issue, but then, a perfect way to blockade a planet would be to pulverize a medium-sized asteroid and cast gravel-sized chunks into unpredictable “ball of yarn” orbits and then watch as outposts on the planet starves for any space access or resources it cannot produce on its own.
Stranger
There’s no way we’d have a self-sustaining space colony by 2060. It certainly won’t have the industrial capability to build its own spacecraft, let alone armed spacecraft. The most effective tactic in an interplanetary conflict would be economic sanctions against the colony, or against the country that is launching supply ships to that colony. Failing that, a missile attack at their launch facility.
Project Orion means atomic bombs. Where would a Mars colony get fissile materials?? Most planets have far less heavy elements near the surface than Earth.
Even for earth, supplying enough fissile material for routine spaceflight might be difficult. Every single push uses 11 kg of plutonium.
There is a small but significant amount of fissile material on the Moon, and it might be worth mining given the right technology; but I don’t think they would be able to manufacture enough atom bombs to supply a fleet of Orions by 2060.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL043061
Maybe by 2160, given enough investment in Moon mining.
It is certainly possible to make nuclear fission weapons with less fissile mass than the natural critical mass of plutonium or uranium with the use of explosive lenses to densify a thin shell of fissile material and the use of neutron-reflecting tamper. Ted Taylor, the physicist and nuclear weapon designer who worked on Project ORION looked at scalability and estimated a much smaller device for interplanetary vessels of a practical size, and separately estimated the smallest possible implosion core to be the size of a golf ball.
However, your essential point remains; although uranium is commonly found in Earth’s crust at trace levels, natural high grade uranium (which is at most ~0.72% [SUP]235[/SUP]U) is not found in great quantity anywhere and is concentrated by volcanic and hydrological mechanisms which are not found on any bodies in the Solar System other than Earth and Io (and maybe Venus, but nobody is going to recover anything from Venus). Uranium does likely exist in rocky asteroids and on the other solid bodies but only an tiny concentrations that would require extensive mining and separation, and then would have to be bred to produce fissile isotopes such as [SUP]235[/SUP]U or [SUP]239[/SUP]Pu which would then need to be concentrated by progressive centrifugal separation or chemical separation which requires a substantial infrastructure.
Thorium is probably somewhat more commonly found but also not in high concentrations, and is not suited to making nuclear fission weapons/bomblets. Thorium is far better suited to a nuclear salt water or fission fragment propulsion system, but it would still require a lot of infrastructure to produce to a suitable fissile grade. In general, nuclear pulse propulsion has a lot of drawbacks as a propulsion system, not the least of which is the minimum inert mass of the vehicle to limit peak propulsion which would require carrying all of the mass up from Earth’s surface and assembly in space. (The original concept for Project ORION is that the vehicle would be built on the surface and launched into space, but this was back in an era where unconfined atmospheric detonation of nuclear weapons was accepted as being necessary and inconsequential; getting anyone to agree to that today would be a risible proposition.)
The sine qua non of a functional human presence beyond low Earth orbit is the ability to obtain the majority of structural materials from space-based resources and in-situ production of all consumables like air, water, and propellants, and that requires a complete infrastructure for mining, fabrication, and transportation. Until that is practicable, any human presence in deep space or on other worlds will be prohibitively expensive for any commercial purpose. Once such an infrastructure exists, it will become exponentially cheaper easier to support a human presence and exploratory efforts for more resources, but there is no current path working toward this other than some fledgling private efforts at surveying the available resources in Near Earth Asteroids. It might be feasible to assume space colonies by 2060 if there were a concerted effort today to develop the necessary technology and infrastructure (and there are no major stumbling blocks) but at the current state of progress it seems highly unlikely even given the most optimistic projections.
Stranger
This is the same mentality that gave us pollution as a problem (local or global). Yes, a little bit won’t hurt. One or two battles, probably not a problem. But after a few dozen shooting wars, all out discharge of hundreds of thousands of rounds in the general area of “travel lanes” for spacecraft - then what? And it doesn’t go away in a hundred years or even ten thousand. Today’s land mine problem is a good analogy.
The gravel in orbit idea is a prime example - okay; you’ve basically rendered the location unusable for anyone for the remainder of written history, unless you are prepared to spend the GDP of a few worlds to clean up the mess. It’s analogous to using a dirty bomb on a neighbor. Plus, the simple solution is to stand off and use unmanned (re)entry launch vehicles for resupply unless your gravel guarantees a 100% kill rate. Three tanks, three engines, three control brains, redundant piping and wiring… With a well-designed redundancy, an unmanned craft might have to be hit several times to guarantee incapacitation.