Sci-fi Weapons, Vehicles and Equipment

You wouldn't need relativistic speeds to make them close long distances fast and do extensive damage to begin with. Duking it out at a distance of even one AU or 5.878625 trillion miles is extremely unlikely even at a 1/4 of that is going to be pretty unlikely. Even a million or two miles is seriously pushing it. A few hundred thousand miles is more likely.

An RKV weapon I can see being shot at something like a planet which is stuck on a predictable path but a moving ship is a different thing. Even a tiny deviation at the point of the shot to the target can produce an extremely large degree of miss at the target point at extreme ranges that isn't with a ship moving in a direction you didn't plan on. Now the closer you get to the target the smaller that degree of miss is likely to be. Unless you are shooting something extremely and unbelievably tough you would not need the speed of a RKV to do serious or even fatal damage or even reach the target at high speed. The amount of energy to get even a low C shot off is pretty damn high there is no reason to do it unless you absolutely have to.

Who watches the watchmen?

Yeah, relativistic is unlikely in the extreme unless your ships stretch into km long and have spinal mounts. I'd say 20-200 km/s is a more likely velocity.

Agreed. There is also the consideration of "What if you miss?" Even at 200km/s it will do a lot of damage to whatever it hits but it is a lot less nasty then a RKV by comparison.

Tungsten and DU have some interesting impact qualities in relatively low weight projectiles. I need to pull up the material density charts I had dug up again. I need to add those to my page of general resources.

Who watches the watchmen?

-wakes up- Huh what? Honor Harrington? Yeah uh, they introduced missiles partway through the series that were basically multi-stage missiles, but given the long-range engagement envelopes of the battles in that setting, the only way for them to be any more effective than the normal missiles was for the Manticorans to develop superluminal communications, which was impossible for a transmitter/receiver that were in the same star system (with the FTL travel technology of the setting, they could sneakernet a message over hundreds of light years in a matter of a few days, but that's not quite true FTL communication).

To David Weber's credit, he paced that development out over the course of many books. The FTL communications rigs first appear in the third book, but are effectively just a wireless telegraph analogue. Ships could send messages by sort of tapping on the fabric between realspace and hyperspace. To an observer who didn't know what was going on, it looked like the ships were having some minor hypernode malfunction (which was basically a yellow flag by itself, given that this is Manticore we're dealing with). In a short story taking place earlier than that, they played with it by having ship captains flicker their gravity wedges as a signal akin to firing off a flare (I guess the real world analog would be a sailing ship raising and lowering a sail, or maybe a coal or oil-fired ship tossing something into the boiler to make a spectacular belch of smoke or something.)

The tech was gradually improved over the books until it could be used for more complex messages, and then for remote fire control for missiles at long ranges, and finally for real-time video teleconferencing from 20 light minutes away (one example had a Manticoran officer signalling the captain of a specific ship that had been trying to lie doggo that not only did he get a stealth recon drone close enough that he read the name of the ship off of their hull, but he wanted to let the Captain know that it looked like one of his hypernodes might be in need of maintenance soon.)

Basically, anyone could have used multi-stage missiles for the extra range, but nobody ever saw any point in the exercise until someone figured out how to communicate with the missile over long ranges to help it work past enemy ECM and such.

So yeah, if you can develop FTL comms (and by extension, FTL sensors), the calculus involved in using any weapon at ranges approaching light seconds become a lot simpler.

edited 13th Sep '14 5:32:07 PM by AFP

Or low level AI. Put a purpose build problem solving computer in to a missile and let it go. Far less need to communicate with it at that point, unless you want to abort the mission.

Phew that might get costly quick though. Ok maybe not an AI but a reasonably advanced targeting computer should be doable. So basically the drone/missile/ship thing rolled into one again.

edited 13th Sep '14 6:54:13 PM by TuefelHundenIV

Who watches the watchmen?

“In a galaxy, where the United Earth Government has fought a civil war, losing several worlds to the Southern Cross and had a war with the Alien Cay Union, hope rides in a ship called Victory ”

~*cue theme music*~

A ship to fight the ESS Victory:

Name: SCSS Amy Komori

Age: Built 15 years before the series takes place

Personality: Cool Ship,

Abilities: A capital ship made to fight the EDF.

Weaknesses:

• Awesome, but Impractical / Crippling Overspecialization:: No Space Marines, there is a company-sized element of Security Forces on board. A capital ship only built for space combat, her class has to escort the fragile crusher ships to take a planet.

• Against Earth ships she’s a Lightning Bruiser , Cay Union ships are faster and have more weapons.

• Army of Thieves and Whores: the image the Southern Cross Mustered Citizenry has after the various wars against Earth. While the SCMC is much more professional, they do emply many privateers. That’s the backstory of Wing Commander Allyus Pomaz.

Goals/Motivation: The crew patrols the Joint Security Area and keep Earth off balance.

Role in the story: The Rival to the ESS Victory

Backstory:

The Rebecca Corbin class battlecruisers are based on Cay Union “Raptor Strike” class ship. They are LightningBruisers made for speed to respond to the EDF’s Bernard Law Montgomery ships. The Amy K. has artificial gravity, jump and warp drives.

Southern Cross doctrine puts a great emphasis on Running the Blockade, they need to get ships past EDF units that would try and take worlds away from them. Older Cay Imperial ships were being trounced by Earth’s Monty-class ships. So they built a ship designed for speed and firepower to escort their crusher ships. It would be able to carry the fight to the EDF. Secretly, the Southern Cross’s Revolutionary Military Council feared that the Cay Union could turn on them. So the newer ships would be built to outrun their Vengence class capital ships.

Commodore Acera Veery is charged with keeping the EDF off balance. While the treaty that ended the One Year War limits ships patrolling the Joint Security Area, Amy K’s speed more than makes up for that. Her mission is to be many places at once.

Relevant Tropes: For the ship:

• Cool Starship: The Amy K. is named after a famous Southern Cross freedom fighter, so her mission is to take the fight to the EDF.
  • Occupiers Out of Our Country: The reason she was named after a famous person
  • Faster-Than-Light Travel
  • Standard Sci-Fi Fleet: a capital ship (Battlecruiser) that is The Mothership,

• Cute Bruiser / The Aesthetics of Technology: the ship has a smooth flowing design and it’s whipple shields make it look like a dolphin or long fish.
  • The SpaceFighters tend to have Nose Art showing a fish with a boxy Earth ship in it’s teeth.

• Space Fighter: a wing of 20 fighters, SCMC doctrine tends to favor Jack of All Stats medium class fighters working in groups. However there are four heavy bombers to support the crusher ships and over match EDF fighters.
  • The Load: the Crusher ships need to be protected as they make planet fall.
  • Beam Spam: SCMC fighters tend to have lots of lasers giving them more shots than EDF fighters and their railguns.

• Macross Missile Massacre
  • Recursive Ammo: The SCMC is quite fond of this

• Kinetic Weapons Are Just Better: The ship has a lot of railguns, both for point defense and larger ones for naval combat.
  • Orbital Bombardment: those guns support units from the Crusher ships, wiping out enemy units below.

• We Will Use Lasers in the Future: the ships energy weapons are powerful, but not up to the Victory class’s standards. They can’t draw additional power from the main engines so this ship can’t Beam Spam. Veery wants to use speed to compensate.

• Alpha Strike: working with her fighters, the Amy K. can dish out a lot of damage.

Relevant Tropes: For the crew:

• Power Trio: Two Guys and a Girl: The Hero and The Lancer, mediated by The Heart
  • The Captain / Lady of War : Commodore Acera Veery
  • Number Two / The Heart: Lieutenant commander Jeri El'hat Masaka
  • The Lancer / Ace Pilot: Wing Commander Allyus Pomaz

• The Crew has:
  • Mildly Military: the SCMC Navy tends to be lax on customs but not discipline.
  • Cold Sniper: Gun crews on Southie ships are famous for hitting ship’s weak points, disabling or crippling enemy ships with few shots.
  • Fighting for a Homeland: the ship’s motto is “Peace, Land, and Justice”
  • Peeling Potatoes / We Will Use Manual Labor in the Future: no food pills for this ship, threats of being sent to work in the galley keeps the conscripts in line. After a few weeks on patrol, everyone is a food critic.

• Nicknaming the Enemy: Icky Vicky vs the Amy K., The SCMC picked up on Victory's nickname after hearing news reports of it's breakdowns in port. When the EDF saw what the Komori could do, even intel officers called her the Amy K. out of respect
  • Reporting Names: Officially the EDF calls all of these ships “Romeo class”, this one is “Romeo 3”

edited 13th Sep '14 11:28:41 PM by TairaMai

All night at the computer, cuz people ain't that great. I keep to myself so I won't be on The First 48

A blockade runner? Those typically don't survive any kind of pitched fight against a real military.

I hope the Amy K ain't built like a blockade runner, simply being used as one.

Nope, she's can dish it out and take it. The ships more of a blockade breaker.

edited 13th Sep '14 11:26:01 PM by TairaMai

All night at the computer, cuz people ain't that great. I keep to myself so I won't be on The First 48

Some of the blockade runners that have been made were surprisingly tough.

Taira: Sounds more like an iron clad.

Who watches the watchmen?

From what I understand(not much), a scram cannon works on the same principle as scramjet engines, but it happens within the barrel, with the specially-shaped projectile passing through a gaseous fuel mix and igniting it through compression, which happens behind it at first, and then around its tail("like two fingers squirting a watermelon seed") by 'supersonic ignition'. It may pass through several different fuel mixes meant for different speeds for continuing acceleration, separated by frangible seals. So it should work in space; Missiles/drones with scramjet engines, probably not. Conventional guns(including those multi-stage ones) are limited by their propellants' speed of sound, and this is a way to go beyond that.

Electrothermal-chemical ignition seems to be about a complex electric primer that creates a burst of plasma to ignite the propellant in a better way. It could be combined with a scram cannon, giving the projectile its initial push(it only works at very high speeds).

edited 14th Sep '14 3:32:14 AM by ManInGray

"So basically the drone/missile/ship thing rolled into one again."

Yep, that's pretty much the way of the future. I advocated once an entire fleet made up those things.

Belesarius: "First, you need a very large lens at the end of your laser."

Not so. One can use a bunch of smaller ones focused on the same spot. It's much more efficient and manageable. It's also a wastevof energy to tilt the entire laser array towards the enemy. Just use mirrors to reflect them where you want them.

edited 14th Sep '14 1:41:09 PM by dvorak

Now everyone pat me on the back and tell me how clever I am!

You could, but there wouldn't be much in the way of net benefit. The lens space basically works out to be the same and now you have to deal with the fire control and maintenance issue of hundreds and hundreds of lasers and the secondary systems needed to make them run.

Additionally, I've never assumed that the lasers would be shifted in their entirety. However, the mirrors and final focusing lenses would still be vulnerable to damage and at the output of anti-ship lasers even a small scratch would be disasterous.

Do you have a link for the "a single scratch is catastrophic" claim? A space combat laser is going to use a very large lens to focus a beam onto a very small area on the target, so that you dont melt the lens (or mirror, whichever). A defect will degrade performance, obviously, by why would it cause additional damage?

Lasers need clean optics. Check Atomic Rocket, there is an anime where one punishment is cleaning the lenses, Gunbuster I think.

All night at the computer, cuz people ain't that great. I keep to myself so I won't be on The First 48

I dunno taira AR seemed to think the Yal 91 was going to work out when the reality was quite different.

Ok I found it. What it boils down to is surface area of the focusing part vs the power of the beam which also dumps heat into the lens. A scratch on the lens serves as a smaller focal point by surface area then the lens as a whole. So when it fires the bit that is scratched is now trying to focus large amount of energy being dumped through it. Like if you have a magnifying glass with a scratch you can see that some of the light is being focus through the scratch.

edited 14th Sep '14 7:41:12 PM by TuefelHundenIV

Who watches the watchmen?

I dont doubt it. But any space combat ship worth its weight in aluminum is going to bring some spares along.

This got me interested, and I started re-reading this old (2009) Rocketpunk Manifesto article on space lasers and combat. Interesting stuff:

"...Thus laser weapons can blind the enemy, temporarily or permanently, at much greater range than they can do serious physical damage to structures. Our first modest laser has a scorch range of 1300 km; the more S Fnal one a scorch range of 2 million km … and the jumbo X-ray laser has a scorch range of 2 billion km, about 14 AU. Spot size (and targeting resolution) is wider by the same proportion, dozens of meters. More rugged sensors are the solution, but it seems likely that weapon lasers can dazzle or blind targets at several times the range at which they can burn through armor."

edited 14th Sep '14 7:39:08 PM by demarquis

The Chinese have used that to dazzle satellites and the Russians built a tank to dazzle targeting devices and optics.

Who watches the watchmen?

Backing up just a little bit...

What do you think a maneuver is? Acceleration, in another direction. Acceleration can be either positive or negative. For example, a negative acceleration on the right of a forward moving object pulls it right. That negative acceleration can be due to anything be it a vernier thruster, a gravity pull, air resistance if terrestrial, or impact with something else.

Yes, except that the thruster won't see the craft breaking up like you propose. Why not? Because in a vacuum it doesn't matter what your velocity is, any thrust will still only stress a missile's structure as though it were moving at walking pace.

edited 15th Sep '14 4:46:34 AM by MattII

of course, this is due to the fact that a thruster has kilometers to accelerate over rather than meters and can afford to pull less Gs.

But remember at relativistic speeds matter no longer behaves "solid". Any perturbation is likely to destroy the projectile.

That's the argument against guided projectiles at Atomic Rocket ranges using Atomic Rocket velocities. If your engagement range is < 1000 km your options are interchangeable and often equivalent.

Plus in the realm of Atomic Rocket ranges measured in significant light-time, if you are NOT shooting at relativistic speeds or the speed of light itself your enemy has literally all day to avoid or intercept your attack.

Which is why you would use a guided missile at those ranges. By the way, you could still use the RKV against relatively stable targets, like spacestations or cities, so the weapon itself is not eliminated as a class.

Another way that the conventional coil or railgun could be used is if the enemy doesnt realize that one is firing at them. That might be possible if you could somehow obscure the energy discharge of the barrel.

Actually large interception/avoidance windows are arguments against long range fights using more conventional but stable (in physics sense) velocities. If the window is too large, you will never hit the enemy no matter how many missiles you spam at him. If he has all day to avoid or intercept, he can meet your attack 1:1 and never be in danger. If he only has about 3 seconds or less between your (unguided) relativistic launch and his demise, that makes for a lot more danger to the enemy.

At 1000 km or less, anything goes.

edited 15th Sep '14 9:29:06 AM by MajorTom