Solid Fueled, Chemical Fueled, and Other Fueled Missile Space Combat Is Difficult...

[Spacescifi]

I recently learned a few things, which when added to what I already knew, changed my view of how space combat would actually go down.

On Earth solid fueled missiles are what everyone uses in war. In space they are of limited value though, since solid fuel missiles burn through their fuel quickly and typically are not designed for toggling thrust on and off to conserve fuel. Additionally solid fuels have an expiration date (about 30 years if I recall correctly from my internet search).

What that means is that not only is their effective range rather short, but that you need someone to resupply or manufacture brand new missiles over time when the originals degrade over the decades. So if you are on one of those generational spaceships solid fueled missiles are not going to last you on your journey. You would have to manufacture new ones and those too would expire with time.

Chemical fueled missiles: These can last indefinitely if properly stored and maintained. The main challenge with these is their lower fuel density per volume... which would force weapon designers to make larger missiles just to hold the chemical fuel... which makes it a huge target and kind of defeats the whole point of a missile in the first place.

Nuclear chemical propellant missiles: Great for space combat since nuclear power if properly utilized can compensate for not having tons of fuel available. Yet you also run into waste heat issues... which may force it to have radiator wings installed, making it a target everyone in the entire solar system can see brightly on their sensors.

Scifi Fusion missiles: We don't even have a way of doing this unless you are talking pulse propulsion using ether pusher plates or magnetic nozzles. Superior to many nuclear chemical missiles with a few exceptions like the dreaded NSWR rocket engine from Zubrin (has deadly chernobyl level exhaust).

Scifi Antimatter fueled missiles: Excellent for range and thrust if we had them but freakishly expensive. Cheaper to use it as a warhead than actual fuel for a disposable missile.

The future: Nuclear chemical fueled missiles seems like the way to go for space combat, especially when you are so far out that you cannot count on being resupplied with fresh chemical missiles when the ones you have already expired.

Your thoughts?

What about this scenario: A generation spaceship on a 200 year journey has to use it's missiles to defend itself near the end of it's journey. Unfortunately the ship designers stocked it with 2,000 solid fueled missiles which have long since expired. The reason? Let's just say there was a war during launch and several ships that were supposed to accompany the generation ship on the journey did not make it. The solid fueled missiles were really useful back then but now?

That is the question. What happens when you attempt to launch 190 year old solid fueled missiles lol?

It seems for generational ships what you should install are RBOD laser cannons... since it should still work with proper maintenance even if 190 years old... I think anyway unless I missed something.

Edited Sunday at 04:56 AM by Spacescifi

[JadeOfMaar]

You're really missing out on exotic (and practical) missile propulsion types:

• Casaba-Howitzer. The missile is a shotgun. (That is, you add a focal gear to, say, an Orion charge, give it enough power to aim itself when thrown out of the ship and have it fire off.) Its nuclear charge is the gun powder and its fragments are the pellets.
• Bomb pumped xasers. Same kind as the Casaba-Howitzer but its attack medium isn't shells but a focused, deadly X-ray pulse.
• SNAK. A graphene sail like attachment to the Casaba-Howitzer. When it tanks the charge it becomes a molten Carbon spear and is akin to a snake spitting venom or a water gun shooting deadly acid.
• Fizzler/Fizzer. A solid rocket but the fuel is fissile fuel + Lithium Deuteride (or is it Hydride?). It consumes itself like a firework sparkler and accelerates with the might (or multiples) of a railgun shot. It would have a payload on top which does not get consumed (so there is still something substantial to hit the enemy with).

I constantly consider these and imagine how space combat scenarios for my own worldbuilding would work out because yes, chemical missiles for cliché WW2 fight dynamics wouldn't actually work when you have battleships that can accelerate at 12 gees for 12 minutes (or hours, I bet). Consequently, traditional PDC gatling guns lose their place. They're instantly fully outclassed by all of these missile types.

 

14 hours ago, Spacescifi said:

Nuclear chemical propellant missiles: -snip- Yet you also run into waste heat issues... which may force it to have radiator wings installed, making it a target everyone in the entire solar system can see brightly on their sensors.

Nah. A fissile powered missile (see the types above) is only going to shine brightly on enemy sensors for the brief moment that it's firing. It's guaranteed going to be hard to dodge because of how fast it's moving afterward. Getting hot enough that it destroys itself in the process is welcome. Don't need guidance and coolant anymore if you can technically insta-hit with the thing.

 

14 hours ago, Spacescifi said:

Scifi Fusion missiles:

Scifi Antimatter fueled missiles: 

These are fundamentally busted if you care about any amount of realism. The reactors for these cannot be built small enough (with known science) and cannot run cold as what nearly every scifi story would have you believe. Also, it's a huge waste of precious superconducting material to use them for something that will be destroyed if it hits or will disappear into the abyss if it misses. Fissile fuel and equipment to harness the released power of that fuel (even if only for a moment) would be very cheap and expendable, I think.

 

14 hours ago, Spacescifi said:

RBOD laser cannons

RBOD sounds like a super weapon. Putting it on a generation ship (which is generally civilian) sounds like painting a big target on it. Macron guns need some love. These would take the place of PDC gatling guns when all missiles can fire at fractions of light speed.

[Spacescifi]

2 hours ago, JadeOfMaar said:

You're really missing out on exotic (and practical) missile propulsion types:

• Casaba-Howitzer. The missile is a shotgun. (That is, you add a focal gear to, say, an Orion charge, give it enough power to aim itself when thrown out of the ship and have it fire off.) Its nuclear charge is the gun powder and its fragments are the pellets.
• Bomb pumped xasers. Same kind as the Casaba-Howitzer but its attack medium isn't shells but a focused, deadly X-ray pulse.
• SNAK. A graphene sail like attachment to the Casaba-Howitzer. When it tanks the charge it becomes a molten Carbon spear and is akin to a snake spitting venom or a water gun shooting deadly acid.
• Fizzler/Fizzer. A solid rocket but the fuel is fissile fuel + Lithium Deuteride (or is it Hydride?). It consumes itself like a firework sparkler and accelerates with the might (or multiples) of a railgun shot. It would have a payload on top which does not get consumed (so there is still something substantial to hit the enemy with).

I constantly consider these and imagine how space combat scenarios for my own worldbuilding would work out because yes, chemical missiles for cliché WW2 fight dynamics wouldn't actually work when you have battleships that can accelerate at 12 gees for 12 minutes (or hours, I bet). Consequently, traditional PDC gatling guns lose their place. They're instantly fully outclassed by all of these missile types.

 

Nah. A fissile powered missile (see the types above) is only going to shine brightly on enemy sensors for the brief moment that it's firing. It's guaranteed going to be hard to dodge because of how fast it's moving afterward. Getting hot enough that it destroys itself in the process is welcome. Don't need guidance and coolant anymore if you can technically insta-hit with the thing.

 

These are fundamentally busted if you care about any amount of realism. The reactors for these cannot be built small enough (with known science) and cannot run cold as what nearly every scifi story would have you believe. Also, it's a huge waste of precious superconducting material to use them for something that will be destroyed if it hits or will disappear into the abyss if it misses. Fissile fuel and equipment to harness the released power of that fuel (even if only for a moment) would be very cheap and expendable, I think.

 

RBOD sounds like a super weapon. Putting it on a generation ship (which is generally civilian) sounds like painting a big target on it. Macron guns need some love. These would take the place of PDC gatling guns when all missiles can fire at fractions of light speed.

 

Good points. Yet even these can be countered by sandcasters. Which means you can turn macron guns into shotguns that fire off clouds of tiny pellets at fractions of light speed to intercept whatever is incoming.

What that means is that instead of a bunch of bright beams criss crossing the dark background of space in a cliche scifi space battle, what you get are a LOT of flashes in empty space. You see a lot of them as incoming fire nears warships as their sandcaster cannons work to blast incoming particles.

The fizzler sounds cool but once again like all solid fuel rockets should expire in 30 years. That's the kind of thing you are more likely to see on orbiting battle stations or moon battle stations that have infrastructure nearby for resupply/manufacture.

It seems the farther out you are away from any hope of resupply/manufacture that missiles become far less useful since they are fundamentally easy to destroy if you see them coming in time. And because space combat is a long range affair by default you usually will. I pity the poor fool who attacks an Earth-like world with spaceships if Earth is armed up for for a real space war.

Since it could throw literal tons of sandcaster flak and fizzlers in the enemy fleet's direction... far more than the fleet should be able to put out.

 

So what am saying I guess is that against casaba howitzers, ultra lasers, and sandcasters, missiles as we commonly know them are virtually obsolete.

 

For example. Let's take a swarm of 100 casaba howitzers fired against 100 nuclear chemical propelled missiles.

Casaba howitzers need nuclear chemical missiles to propel them otherwise they're only good for line of sight/sensor point defense.

Casaba howitzers could intercept missiles with relative ease since they don't need to actually collide with enemy missiles because their shrapnel will at fractions of light speed.

Edited Sunday at 08:45 PM by Spacescifi

[magnemoe]

1 hour ago, JadeOfMaar said:

You're really missing out on exotic (and practical) missile propulsion types:

• Casaba-Howitzer. The missile is a shotgun. (That is, you add a focal gear to, say, an Orion charge, give it enough power to aim itself when thrown out of the ship and have it fire off.) Its nuclear charge is the gun powder and its fragments are the pellets.
• Bomb pumped xasers. Same kind as the Casaba-Howitzer but its attack medium isn't shells but a focused, deadly X-ray pulse.
• SNAK. A graphene sail like attachment to the Casaba-Howitzer. When it tanks the charge it becomes a molten Carbon spear and is akin to a snake spitting venom or a water gun shooting deadly acid.
• Fizzler/Fizzer. A solid rocket but the fuel is fissile fuel + Lithium Deuteride (or is it Hydride?). It consumes itself like a firework sparkler and accelerates with the might (or multiples) of a railgun shot. It would have a payload on top which does not get consumed (so there is still something substantial to hit the enemy with).

I constantly consider these and imagine how space combat scenarios for my own worldbuilding would work out because yes, chemical missiles for cliché WW2 fight dynamics wouldn't actually work when you have battleships that can accelerate at 12 gees for 12 minutes (or hours, I bet). Consequently, traditional PDC gatling guns lose their place. They're instantly fully outclassed by all of these missile types.

 

Nah. A fissile powered missile (see the types above) is only going to shine brightly on enemy sensors for the brief moment that it's firing. It's guaranteed going to be hard to dodge because of how fast it's moving afterward. Getting hot enough that it destroys itself in the process is welcome. Don't need guidance and coolant anymore if you can technically insta-hit with the thing.

 

These are fundamentally busted if you care about any amount of realism. The reactors for these cannot be built small enough (with known science) and cannot run cold as what nearly every scifi story would have you believe. Also, it's a huge waste of precious superconducting material to use them for something that will be destroyed if it hits or will disappear into the abyss if it misses. Fissile fuel and equipment to harness the released power of that fuel (even if only for a moment) would be very cheap and expendable, I think.

 

RBOD sounds like a super weapon. Putting it on a generation ship (which is generally civilian) sounds like painting a big target on it. Macron guns need some love. These would take the place of PDC gatling guns when all missiles can fire at fractions of light speed.

Bomb pumped xasers is very nice but still not missile range, they simply extend the danger zone around an passing missile, its still very dangerous 10.000 km out but this well inside secondary laser gun range. 
If we assume good fusion reactors is an thing who is pretty required for an hard sci-fi setting like the expanse. 
However engines like orion pulse nuclear get much better as larger they are and most fusion design has lower limit on size. 
So the larger the ship who more efficient your engine is, this makes the missile even weaker. 
More crazy designs like nuclear salt water or fizzler make more sense for missiles, missile or more likely its warheads will have an second stage, probably an rapid burning solid engine for an intercept trajectory. 
This is dropped and blow up into decoys while the warheads are stealthy and dark. 
 

[JadeOfMaar]

4 minutes ago, magnemoe said:

Bomb pumped xasers is very nice but still not missile range, they simply extend the danger zone around an passing missile, its still very dangerous 10.000 km out but this well inside secondary laser gun range. 

That's very nice to know! Thanks!

 

[Deadly_Laser]

I feel like with everything mentioned railguns can still be fairly effective against large ships, especially since the payload can be made pretty hard to detect by stripping the metal case as the shell leaves the barrel, and the payload can be basically anything from a tungsten core to a nuclear shotgun or an antimatter bomb, just depends on how much capacitance and power draw your ship can handle.

[Spacescifi]

17 minutes ago, Deadly_Laser said:

I feel like with everything mentioned railguns can still be fairly effective against large ships, especially since the payload can be made pretty hard to detect by stripping the metal case as the shell leaves the barrel, and the payload can be basically anything from a tungsten core to a nuclear shotgun or an antimatter bomb, just depends on how much capacitance and power draw your ship can handle.

 

Space combat is dependent on effective weapons range. Macron/sandcasters travel at fractions of lightspeed and can hit like a bomb. Railgun rounds are fast but not THAT fast.

Space combat by default is long range... unless you can scifi up an alternative (like dropping out of warp nearby while somehow immediately changing your inertial heading to match your target's without doing it beforehand).

Long range effective combat is supreme in space combat.

Which means before railgun rounds get anywhere near a large spaceship they could get hit dozens of times by it's longer ranged macron/sandcaster guns. Which could either knock them off course or destroy them outright.

Slower top speed weapons ultimately just become point defense weapons, since they are not catching spaceships unless the spaceships are on an intercept course anyway. Basically they are ideal for static defense of bases and spacestations, but spaceships that move need the fastest most effective long ranged weapons available.

 

[Deadly_Laser]

1 hour ago, Spacescifi said:

 

Space combat is dependent on effective weapons range. Macron/sandcasters travel at fractions of lightspeed and can hit like a bomb. Railgun rounds are fast but not THAT fast.

Space combat by default is long range... unless you can scifi up an alternative (like dropping out of warp nearby while somehow immediately changing your inertial heading to match your target's without doing it beforehand).

Long range effective combat is supreme in space combat.

Which means before railgun rounds get anywhere near a large spaceship they could get hit dozens of times by it's longer ranged macron/sandcaster guns. Which could either knock them off course or destroy them outright.

Slower top speed weapons ultimately just become point defense weapons, since they are not catching spaceships unless the spaceships are on an intercept course anyway. Basically they are ideal for static defense of bases and spacestations, but spaceships that move need the fastest most effective long ranged weapons available.

 

Well, depends on the engagement, My point is that railguns don't necessarily have to be used as precision weapons, but as payload delivery systems instead of missiles, something closer to a mine than to a sniper rifle. Macrons are very powerful but the accelerator setup is going to be fairly complicated, so I wouldn't expect them to be fitted on everything.

[Deadly_Laser]

There's also a sort of middle option: a rapid-fire coilgun throwing mm-sized metal pellets at hundreds of km/s. It's not as range-effective as a macron gun but a lot simpler in terms of repairs and upkeep while still being very powerful.

https://toughsf.blogspot.com/2016/10/the-solution-to-long-range-space-combat.html

[magnemoe]

6 hours ago, Spacescifi said:

Space combat is dependent on effective weapons range. Macron/sandcasters travel at fractions of lightspeed and can hit like a bomb. Railgun rounds are fast but not THAT fast.

Space combat by default is long range... unless you can scifi up an alternative (like dropping out of warp nearby while somehow immediately changing your inertial heading to match your target's without doing it beforehand).

Long range effective combat is supreme in space combat.

Which means before railgun rounds get anywhere near a large spaceship they could get hit dozens of times by it's longer ranged macron/sandcaster guns. Which could either knock them off course or destroy them outright.

Slower top speed weapons ultimately just become point defense weapons, since they are not catching spaceships unless the spaceships are on an intercept course anyway. Basically they are ideal for static defense of bases and spacestations, but spaceships that move need the fastest most effective long ranged weapons available.

True, however Macron/sandcasters can be efficiently armored against using many thin spaced out plates or even foil, but it will be very effective against optic including laser mirrors. 
So you send out a swarm of missiles or rail gun rounds, then use Macron/sandcasters to suppress enemy defensive lasers. 

[Natorius]

6 hours ago, Spacescifi said:

Space combat by default is long range... unless you can scifi up an alternative (like dropping out of warp nearby while somehow immediately changing your inertial heading to match your target's without doing it beforehand).

I love the concept of this - scan your target and determine their motion relative to their frame of reference, then match that velocity within your own frame of reference so when you "drop" in you're moving correctly. Lots of cool side effects like it being difficult to match targets when there's a huge difference in local gravitation effects e.g. you're orbiting close to a gas giant and they're in deep space.

[Spacescifi]

4 hours ago, Natorius said:

I love the concept of this - scan your target and determine their motion relative to their frame of reference, then match that velocity within your own frame of reference so when you "drop" in you're moving correctly. Lots of cool side effects like it being difficult to match targets when there's a huge difference in local gravitation effects e.g. you're orbiting close to a gas giant and they're in deep space.

 

If your scanners/sensors follow current understanding of physics they are limited to lightspeed. Which means any calculation you do of a target vessel's location will be where the target was and you have to make an educated guess about where it will be next to even match it's speed and get the drop on it by warping in to the correct distance.

Granted... this becomes easier to do when vessels don't have super efficient propulsion methods, since making a lot of course corrections costs propellant and propellent is finite.

If they have some kind of weird vacuum or diametric drive that does not even require exhausting  propellant of any kind propellant then all bets are off though.