ravener

the sabot is still hitting the ship, it woul probbably still penetrate the hull, but the penetrator would continue going when the sabot stops. countering a kinetic impact weapon is a lot harder than an explosive round, for that you just need a little heat. with a KE weapon you need to physically intercept the round with enough force for it to either miss or no longer have enough force to be an issue.

most sci fi has some sort to compact, high power, high isp engine. in one setting it is stutterwarp, in another it's antimatter drives. aleredy now we can effectively counter most explosive based weapons (HEAT rounds and missiles) if we really wanted. the russians have a system that detonated the incoming warhead in flight with a shapecharge. if we can do it now we can probbably do it not far in the future.

but they still need propulsion in flight. if the engine/fuel tank was to be damaged or ruptured it would probbably not hit its target.

but if they arent kinetic impact weapons they are counterable, they are also a lot more expensive and harder to make in a crude ish space factory where the mills and 3d printers only go down to a few houndreds of a mm.

but i dont think the powder would burn accurately enough or the barrel be precise enough for more than some tens to maybe a few houndred kilometers.

but it is way easier to counter, the small crossection is to better penetrate the hull of an enemy ship and i dont advocate a discarding sabot, it could stay with the penetrator until impact where the penetrator leaves the sabot behind.

planes rely on countermeasures, there is very little you can do when a 250kg tungsten penetrator is hurteling towards you from a capital ship main cannon.

i dont think a cannon would be accurate enough to reliably hit a target on the other side of the planet, i dont even think it is accurate enough to go out to distances where orbit even matters in the trajectory calculation (okay, maybe a little.) at a maximum i would guess it could reliably hit something out to 100km with a long barrel and a static (ish) target in relation to the fiering ship.

it probbably gets pretty hot from friction, but you could always cool the projectile some before fiering and discard some of the hot sabot. space. cold projectile in the first place, many options.

yes, it has been mentioned. it was never used in combat though (obviously) so it would be interresting to see how effective it would be.

this is [sCI FI THEORY]. a ship built for combat has to be able to survive combat. if autocannons, misslies and lasers are the weapons of a given sci fi setting you need ships that can handle some amount of pummeling.

here is the cannon model with a slightly longer barrel (about 3x barrel length )

note that on a space ship a cannon of this size would be akin to a naval cannon on a battleship. 20mm autocannons would be extremely dangerous, but a pennetrator from a 400mm cannon is nothing to joke about. this is a weapon that would take almost anything down in one or two shots.

spaceships. armour thicknesses are probbably not that high as heavy armour isnt really useful in space. i know it is extremely short, that's why it's so thick, so it accelerates fast in the little time it has. the model i made is not that important though, it could easilly have multiple times longer barrel, i am just saying that a long barrel might not be the best in space combat where fast gimballing might mean life or death as engagement times are very short.

if is issupposed to be a warship it needs armour of some sort, most likely a mix of thermal (insulation against lasers) and steel armour. we are talking sci fi here, so propulsion might not be an issue. steel armour of almost ANY thickness is an effective heatsink, the mass of the hull wil almost ALWAYS be higher than the weapons it mounts. if the hull is twenty times the weight of the cannon, it can store twenty times more heat than the cannon alone and it could just be a buffer so the radiators can "suck" the heat out later. the heat issue isnt so bad though, i think we agree there, the penetrator can be pretty small, the bore diameter is just so we can get away with a shorter gun.

but the weaponsystem itself is what is in question here. a spaceship with catapults is useless, doesent matter how advanced it is. the weapon system has to match the capabilities of the vihecle.

we are in agreement then.

i dont think the heat from the cannon would be the issue. if you ship can handle sunheating it can handle the small amount of heat from the cannon. imagine 100+tonnes of steel armour on a sizable warship, you could dump a lot of heat into that before it becomes an issue. in short, any ship should have the heat dissapation capabilities to handle a cannon, even ISS could probbably handle it with its radiators. depends. a hellfire missile mounted on a WW2 aircraft is pretty destructive, almost as much as when mounted on an attack chopper.

propulsion method is smokeless gunpowder. current tech. it works great in space, all the oxygen is contained in the gunpowder. how do you think oxygen from the atmo would get into the reaction in a rifle? a regular earth gun would work great in space, a glock or 1911 in space? no problem. also, "what to do with the gasses?" uh... accelerate a projectile? you could transfer the heat into the hull ( probbably mild steel, we are talking about a warship here), the heat would be radiated by the hull and/or would be stored there.

the heat from the cannon is easilly dissapated with some heat pipes, the issue at the recieving end however are pretty dire as it is concentrated on a pretty small area. it it was to hit a fuel tank it would not only vent the fuel, but also bring a large amount of it to quite high temperatures. if it hits the crew compartment (assuming there is one) the overpreassure would be the greater problem, that would probbably also rupture any liquid holding tanks when i think about it. EDIT: it also turns out that a cannon is an eficcient way to accelerate a projectile. it is lighter, cooler, more reloadable and more reliable than a railgun and a LOT cooler than a laser (temperature).

in sci fi games and stories you always need some sort of armament, this is mostly lasers, beams and rockets, but could a cannon be a useful addition to a sci fi setting? also, sorry in advance for my more than likely ****ty english obvious points before i get to space cannon design: cons to cannons in space: -weight. cannons are notoriously heavy in addition to heavy ammo. -recoil. if your ship has limited fuel to correct the trajectory, you might not be able to afford wasting fuel correcting for recoil. -accuracy. if you work on ranges over a few tens of kilometers and/or fire on a target that is accelerating or manouvering in general hitting might be a problem. -speed. a good cannon might get the projectile up to 1800m/s. intercepting a target moving faster than that relative to your ship is only possible if it moves towards you. -gyro stabilisation. to impact in the correct orientation without active steering you need to gyrostabilize the shell. fin stabilization doesent work in a vaccum. this isnt a huge issue, but it requiers rifled barrels. pros to cannons in space: -cost. in a world where we have advanced production and mining capabilities in space steel will be abundant in orbit as the iron is pretty common in asteroidds we mine. cannons expend little "advanced" materials and can be produced entirely from steel, chrome, nickel and a little carbon, all of which are easy to mine. both the cannon and its ammo can be produced with pretty crude production facilities. - interceptability. a tungsten rod moving towards you is close to impossible to stop. -damage. a laser is pretty nice at range, but within the range of a cannon it deals a pretty hard blow, penetrating everything that isnt extremely heavily armoured. -accuracy. although a cannon has miserable accuracy compared to a guided missile, it has a great accuracy in space. since you are fiering in a microgravity enviroment it is effectivly shooting in a straight line, removing the issues of wind conditions and dropoff from gravity. here is a mock up of a cannon and a sabo shell. cannon length: why so short cannon? well, in space you get a slight boost to power since there is a vaccum on the outside. also, a long cannon is heavy, and weight is a huge concern, even in sci fi. if the barrel doubbles the weight, why not half the length and get 50% more cannons?. a recoilless rifle could be better due to it not affecting the orbit, but it would restrict loading and then also the combat eficciency of the ship. i'm no engineer, so lots of stuff is overdimentioned or underdimentioned, but the bore diameter is on purpose. a huge bore helps with the short barrel length. the sabo round would be burried deep inside the cartridge/shell in a perforated flash tube surrounded by solid fuel, so the barrel is effectively a little longer than it looks since the projectile starts further back. i havent covered the autoloader here (it obviously cant be manually loaded), but i imagine it being an arm that lifts the new shell up to the cannon while catching the remainder of the spent shell for storage (we dont want unnessecary debris do we?). ammo: the obvious choice for a cannon on a space warship is a heavy penetrator projectile as it is the hardest to intercept (if you use a shape charge, why not just use a missile? you loose some penetration ability and a lot of survivability for the projectile. versus a hardned, armoured target you would obviously prefer a tungsten penetrator, but that is hard to get and is maybe unnecessarily heavy. hardned steel should do. the sabo doesent have to be discarding since its only job is to accelerate the projectile and there is no air resistance. the sabo would have to be made from mild steel, aluminium, copper, lead or maybe tin. it just needs to be able to gyrostabilize the whole projectile. the sabo should discard on impact, if it stayed with the penetrator it would defeat the purpose of a penetrator. i might have overdimentioned the penetrator a tad, it could probbably do with being a lot smaller. i'm not covering the turret this would be mounted on either as that is common amongst most sci fi weapon systems.

you can aleredy do this, i cant remember how, but there is an option in some config file that allowes you to move kerbals decupled from camera movement. i dont know how you would go about tracking the kerbal again though.

aleredy suggested, probbably not gonna happen. i like the idea though.

can it be that they dont consult rocket scientists when making documentaries on rockets?

this is the wikipedia article on skip reentry, but i have seen this one note before and it doesent seem to make sense. ok, here it seems to make sense as it puts in an IF, but i have seen this said about shuttle reentry and reentry of soyuz craft as well during documentaries. it just doesent seem to add up as none of those craft has the nessecary energy for escape.