Realistic spaceships, mecha, and other sci-fi goodies

[Foster]

Yes, but size offers capability.

I'd rather have a single Seawolf-class than a trillion Holland P-class submarines

Space is big, I'd rather not starve to death AND die of old-age before reaching my objecive.

[Kadaeux]

The main problem with huge ships is not the size limitation, nor are they inherently slower (but tensile strength IS a measure of surface area, NOT volume, so there IS a point at which the thrust will disintigrate due to insufficient tensile strength)

The problem is economics.

Remember, for the price of a single Executor, I could field a thousand Imperial-class star destroyers.

For the price of a single Imperial-class, I could field a thousand 160-meter cruisers.

People don't consider this in many settings. A lot of people thing twice the length means twice as big. It doesn't.

People consider it all the time. When you have the resources of a significant portion of the galaxy at your disposal, as well as manpower, if anything the Imperial Navy was UNDERequipped. (25'000 Star Destroyers, unknown number of support ships at the empires height) Yes the Executor was worth a lot more than a Star Destroyer. But it was built as a flagship. A task at which it excelled.

As for space fighters being unrealistic? That's completely wrong. We have fighters now, all you have to do is modify them to suit vacuum, replacing their engines with something that works in space, and you have space fighters. The US Navy claims that the F-18 hornet costs $29-$52 million. And it is 17.1 meters in length. I did NOT make these figures up when doing the comparison.

An F-18 Hornet costs 29-52 Million Dollars. If you wanted to have an estimate on what a space fighter would be worth you would not be looking at a 10-20 year old airframe design. You'd be looking at something like the F-22 which is $150 Million US per unit, and like the F-18 doesn't have the complete life support needed, doesn't have the thrusters required, doesn't have the right engines, an airbreathing engine is cheaper than the rocket motors used by spacecraft in case you didn't know. THEN there would be the dedicated avionics suite you'd have to design for operation in space. Then there are the more powerful sensors you would need to engage at a longer range.

Then we have the Space Shuttle which costs a Billion + just to build.

You'd be looking no less than a billion dollars per unit.

As far as first shot first kill weapons... that only applies if you have weapons powerful enough to kill in one shot. If you allow technology such as force fields and advanced armor (technology is one of those areas where we can't say whether or not it's realistic, it's one of the universal consistencies), then firing a laser at long-range probably won't be a one-hit kill, as laser beams widen with range, being dispersed over a wider surface.

Yes Lasers would likely not be one-hit-kill weapons. Indeed, they would likely be used only for point defence in favour of long-ranged missiles with nuclear warheads. Adding in Force Fields, as it stands in this day and age, means you are no longer doing realistic science fiction.

Stealth in space is another one of those technology things. Our current technology forbids it. Doesn't mean you can't add tech to the setting to make stealth more possible. Especially considering space is not a true vaccuum.

The moment you bullshit technology in to allow stealth you are no longer doing realistic Science Fiction.

Spherical spaceships... actually have both strengths and weaknesses. What's easier to hit with a gun, a circular target, or a long piece of tape? If a ship is designed to be facing its target and attacking in a single direction, as well as taking damage from a single source, it's harder to hit, and harder to get a non-glancing blow, on a flat wedge-shaped ship than it is on a sphere. But that wedge-shaped ship is vulnerable to attacks from above and below.

If you are capable of hitting a 100m sphere at 1-2 lightseconds you are capable of hitting the long piece of tape just as easily.

A sphere is amazing at fighting in all direction at once. But when firepower is focused from a single direction, there are more efficient shapes. Look at a modern tank... it's designed to take hits to the front. And its armor is angled to deflect hits to the front. It makes a good design for a spaceship designed to take hits to the front, as well.

No. A sphere is the optimal design for fighting in any way shape or form in space. You're not going to be relying on lasers for damage despite what you may believe, it takes too long for them to do their damage and at extreme range your enemy can keep you from concentrating on a single point with trivial ease. Note that if you DID have a laser large enough for a one-hit kill, you'll be visible from MUCH further away than a ship using kinetic weapons or missiles.

You do NOT want to design a ship whose firepower is focussed along one, or a small, series of axises, this limits the directions you can roll and rotate in to take stress from existing sections. Tell me. What happens when your wedge has to flip over and begin its deceleration burn? Suddenly your enemy has a MUCH easier target to see and not only that, but because you made your ship in an absurd shape and design you can't bring any firepower to compensate for this! A Warship in Space, Realistically, would not be in a constant course. This = Suicide. Your notion of a ship with forward focussed firepower and defences creates a weaker ship not a stronger one.

- - - Updated - - -

Yes, but size offers capability.

I'd rather have a single Seawolf-class than a trillion Holland P-class submarines

Space is big, I'd rather not starve to death AND die of old-age before reaching my objecive.

I disagreed. I'd rather have the Trillion Holland P-class submarines.




















Which I would then sell and buy as many Seawolf class as I could with the money raised.

[Marrone]

Kadaeux, I'm a huge fan of your work. But I have a question: a lot of your answers make sense, but I think it's about time we rephrase some of these questions. Start thinking a little more pro-actively.

For example, with stealth. I read the article you've provided and I get it-- if I got into my spaceship right now, our modern technology could spot my ship even if I tried to refrigerate it or if I turned off my power. . .That's all fine and dandy. I know you can see my emissions and the particles the ship's rockets leave behind. But what if it's a matter of stealth between ships instead of planetary (read: stationary) bodies? Would your ship have enough power to actively (or passively) detect my ship if, say, my ship turned off it's power or refrigerated it's engine or whatever?

Sure, it might take 4 hours to scan the sky around you. . .Except we're not looking at the sky. We're looking at space with 3 dimensions all around. I'm not really sure what the mathematical optics are for that, but something tells me it isn't "eight" because when I look upwards at the sky I'm not on the Earths center. . . This is just something I'm confused about.

Furthermore, I think stealth has a better chance through computers. If you can send a virus into a ships computer, or not even a virus as much as a subtly invasive program that's designed to omit the blot you make on their radar, would that necessarily count as stealth?

So, when regarding stealth, I'd look at the competency of sensors and the usage of virus' to reduce the competency of sensors. That seems much more viable than, well, derp cloak ship lolol. . .Would this count as stealth though, necessarily?

Also, I would suggest we look at "what works" more than "what works effectively". . .I mean, it'd just make things a bit more interesting. Cool, a sphere has pros and cons with perfect cylinders. But if they can both actually-- and seriously-- manuever in space, different functions could be assigned that I'm sure are perfectly practical.

Another thing, Kadaeux, is that you said that "millions and millions of starships in space fighting eachother" (well, you said something LIKE that) is unrealistic. . .And I'm going to have to disagree with you. It's entirely possible to make five bajillion space ships and then have everyone say, "Hey, I'm going to go out into space and kill anything I see" all at once. Improbable, yeah, but not impossible. Is it highly impractical, especially once debris kind of becomes awefully deadly shrapnel that makes "everywhere" look like an understatement. It's more realistic when you have a terrible space admiral who has a problem compensating for his personal problems. . .

Also, a note on lasers, I'm pretty sure they're invisible in a vaccuum. When one particular old Sci-Fi novel (I think it was by Asimov) used some kind of laser that you COULD see in space it was later justified that it was both a laser and a ballistic weapon (It shot bits of metal). What are the possibilities for mounting that on a non-stationary spacecraft for conventional warfare?

Also, Kadaeux, I'm making an RP sometime soon, and I think I've referenced you on multiple occasions. . .I'm actually looking at this thread for inspiration and justification, since I plan on it being as diamond as possible.

[Foster]

Which is one Seawolf.

I'll also disagree with both of you, but for none of the reasons already outlined, and without contesting the points made.

Simply, just because you're have a heading in one direction, does not prevent your ship from maintining an intercept-bearing upon the enemy... even when accelerating randomly.

This is especially fun when you have a cylinder pulling a crazy-ivan with a tumbling-pigeon manuver while spamming smart-missiles with laser-based ESM/ECCM.
-So now you have a target, spaming chaff, that varies in apparent dimensions, and is accelerating in random directions as a bajillion incoming nuclear-pumped XASERs blind the shit out of your radar.

About a half-second later the kinetic missiles impact at roughly the speed of light. Even their debris/shrapnel is fatal.

[Kadaeux]

Kadaeux, I'm a huge fan of your work. But I have a question: a lot of your answers make sense, but I think it's about time we rephrase some of these questions. Start thinking a little more pro-actively.

For example, with stealth. I read the article you've provided and I get it-- if I got into my spaceship right now, our modern technology could spot my ship even if I tried to refrigerate it or if I turned off my power. . .That's all fine and dandy. I know you can see my emissions and the particles the ship's rockets leave behind. But what if it's a matter of stealth between ships instead of planetary (read: stationary) bodies? Would your ship have enough power to actively (or passively) detect my ship if, say, my ship turned off it's power or refrigerated it's engine or whatever?

Yes easily. Our Satellites can do it off of batteries and solar power. A nuclear powered space warship would be able to do it trivially. It would in fact be easier for a ship to do so. (Of course, said ship is also going to be visible to the ship it's spotting.)

Sure, it might take 4 hours to scan the sky around you. . .Except we're not looking at the sky. We're looking at space with 3 dimensions all around. I'm not really sure what the mathematical optics are for that, but something tells me it isn't "eight" because when I look upwards at the sky I'm not on the Earths center. . . This is just something I'm confused about.

It's easier for a ship as it doesn't have a whole planet blocking its view of the sky. It also doesn't have atmosphere or clouds blocking its telescopes etc.

Furthermore, I think stealth has a better chance through computers. If you can send a virus into a ships computer, or not even a virus as much as a subtly invasive program that's designed to omit the blot you make on their radar, would that necessarily count as stealth?

No. Because if you can see the enemy to send a virus at them what makes you think they won't do the same to you. Additionally, realistically no ship could ever be brought down by a broadcast virus like seen in fiction so often.

Your weapons, sensors etc aren't going to accept any wireless connections. In fact they won't be capable of doing so for that very reason.

So, when regarding stealth, I'd look at the competency of sensors and the usage of virus' to reduce the competency of sensors. That seems much more viable than, well, derp cloak ship lolol. . .Would this count as stealth though, necessarily?

As outlined above, no sensor will be susceptible to a virus to begin with.

Also, I would suggest we look at "what works" more than "what works effectively". . .I mean, it'd just make things a bit more interesting. Cool, a sphere has pros and cons with perfect cylinders. But if they can both actually-- and seriously-- manuever in space, different functions could be assigned that I'm sure are perfectly practical.

Another thing, Kadaeux, is that you said that "millions and millions of starships in space fighting eachother" (well, you said something LIKE that) is unrealistic. . .And I'm going to have to disagree with you. It's entirely possible to make five bajillion space ships and then have everyone say, "Hey, I'm going to go out into space and kill anything I see" all at once. Improbable, yeah, but not impossible. Is it highly impractical, especially once debris kind of becomes awefully deadly shrapnel that makes "everywhere" look like an understatement. It's more realistic when you have a terrible space admiral who has a problem compensating for his personal problems. . .

No that comes down to economy. A ship is, by default, more expensive and infinitely harder to replace than an infantryman. Add in that you would not muster that kind of force together, command and control would become pretty difficult etc.

Also, a note on lasers, I'm pretty sure they're invisible in a vaccuum. When one particular old Sci-Fi novel (I think it was by Asimov) used some kind of laser that you COULD see in space it was later justified that it was both a laser and a ballistic weapon (It shot bits of metal). What are the possibilities for mounting that on a non-stationary spacecraft for conventional warfare?

Pointless, invisible lasers are where the higher damage wavelengths are. Particle Beams also occupy a lot of space.

Also, Kadaeux, I'm making an RP sometime soon, and I think I've referenced you on multiple occasions. . .I'm actually looking at this thread for inspiration and justification, since I plan on it being as diamond as possible.

I'm flattered (Also one should note that I am talking 100% hard science except for handwaving FTL, I prefer not to do a 100% Hard Scifi.)

One of the best examples of Hard Scifi (in a soft scifi environment mind you!) was Peter F Hamilton's Nights Dawn Trilogy.




The Adamist starships were pretty much restricted to Hard Scifi (They were also restricted to sphere-shaped ships due to how the FTL drive worked for Adamist ships)

[Marrone]

Yes easily. Our Satellites can do it off of batteries and solar power. A nuclear powered space warship would be able to do it trivially. It would in fact be easier for a ship to do so. (Of course, said ship is also going to be visible to the ship it's spotting.)

Sweet.

It's easier for a ship as it doesn't have a whole planet blocking its view of the sky. It also doesn't have atmosphere or clouds blocking its telescopes etc.

Oh wow, freaking eureka. Stealth might be attained if you put fog machines on your ship.

YES.

Actually, on one hand, that might be a viable path to explore stealth, and on the other hand the ship with the 'fog machine' will have it's OWN sensors combobbled. . .which only makes it useful for hiding rather than secretly attacking.

(edit: these wouldn't be the fog machines you buy at Party City. . .they'd probably take up more energy than they're worth. It might be viable for some kind of last-ditch emergency civilian transport or something. . .I dunno. You'd probably need a very specific type of gas to evade the numerous types of scanners, and it might be heavy/flammable which just means bad news bears to anyone inside.)

No. Because if you can see the enemy to send a virus at them what makes you think they won't do the same to you. Additionally, realistically no ship could ever be brought down by a broadcast virus like seen in fiction so often.

Your weapons, sensors etc aren't going to accept any wireless connections. In fact they won't be capable of doing so for that very reason.

Well, lets get back on this, lets be a little creative. What if it was sabotoged? A betrayal-- or when the ship was parked it's computers were hacked while it was in docking? I'm not really concerned about "how" to get a virus into a ship-- that's all small stuff. I mean, it's too easy just to make it so the virus deactivates or self-destructs parts of the ship. Something more subtle, like making a modulation to the sensors as to make that blot of energy seem to not be there. That's what I'm looking at.

[Asuras]

Mecha

The very concept of Mecha is that they are based on "rule of cool" mechanics. Because what's more cool than a giant humanoid robot blowing up another giant humanoid robot with a giant space gun? Two giant humanoid robots blowing up two other giant humanoid robots, that's what!

However, mecha by their design are inherently unrealistic. This does not mean that they can't exist in a setting... they just wouldn't be the super-weapons that they are often portrayed as in anime. Pieces of military equipment is all they'd really be... real-robot genre rather than super-robot genre, basically.

But even real-robot genre can be unrealistic. There are several factors to overcome when making mecha to begin with.

First off, standing on two legs is inherently unstable. Ever try to make a two-legged table, or a two-legged chair? It requires amazing balance just to be able to stand upright... and it's also very easy to knock a two-legged object down. Bigger feet do add to stability, but more feet adds much more stability. However, since most people thing of humanoid mecha when they think of mecha, I'll focus primarily on two-legged mecha.

A stable robot might use three or more legs for increased stability. Or if you want to make them cool, just give them large enough legs and feet to support their massive size. Square-cube mechanics make it difficult for huge robots to stand on two feet without collapsing under their own weight, so the legs would likely be proportionally larger than human legs.

Another thing to consider is that standing upright makes you a larger target. One of the first thing soldiers do in combat is drop to a prone or kneeling position, making themselves a smaller target, and take cover behind objects. Upright mecha would have much greater difficulty in doing so, as large size makes them inherently unwieldy. Not to say it can't be done, but it takes longer.

Also, the humanoid form has a great deal of surface area... apparently evolved due to the fact that the tropical environment of Africa where humans are said to have originated from is super hot. Also the reason we have to wear jackets in the cold... too much heat escapes from our high surface skin. The problem with having a high surface area is that it is difficult to put armor on a humanoid form. Since armors protection is measured by its thickness, in order to provide sufficiently thick armor on a humanoid from, it has to be a whole lot more massive than, say, the same thickness on a sphere. So mecha are likely to be fairly lightly armored... not heavily armored. Or else they'd collapse under their own weight.

There are many other examples to consider when designing realistic mecha, but suffice to say that they're very different than what most people think of. They can be done, but a lot of realistic-setting countries probably wouldn't bother... tanks are more efficient, if less maneuverable.

Of course, you might also consider removing the humanoid form from mecha entirely and just use multi-legged mecha. Spiders and Scorpions are rather efficient designs, many legged and easily armored. Send in the spider mechs! Take on the roboscorpions!

The thing is, you seem to be taking 'mecha' as some anime-born concept; over-the-top, so to speak. Now of course super robots are out of the question (but you can't deny their coolness!), but military mecha are not only possible, but capable of doing more than an equivalently-armed tank. There are multiple issues, of course; one being that a tank born in a mecha-capable time would likely also have greater technology put into it which may rival that of a mecha and make it inherently useless, but the mecha will always have certain advantages.

The first thing one has to get over is the belief that mecha are undeniably inefficient. Take one look at humans and you'll see that we're fairly efficient with what we have. We can be extremely strong or extremely fast. We're certainly more dexterous than most animals. We can also change our height, either by crouching, standing, or proning... As opposed to a tank, which would likely have one height. Mecha can shoot around corners, theoretically reload themselves (as opposed to a tank which must have a crew to resupply). Getting over the problem of balance is simply an issue in computing and construction, which is entirely possible with today's technology.

If you keep thinking in terms of 'now' then of course futuristic designs would seem impossible. I'll bet leaving to space was never thought possible, but look at where we are now! Of course absence of evidence to the contrary doesn't necessarily mean that it is possible... We just have to wait and see. I've seen many videos of bipedal robots working better and better with each passing year. I'm of the opinion that we won't ever really have particularly large mecha like those of a toned-down Armored Core 5 or similar, but rather more human-sized ones. Such are definitely more plausible (even today!).

I'll agree four-legged mecha would be better, but in some respects they'd be larger and more cumbersome than a two-legged mecha. Each would have its advantages, again.

[Sir Beowulf]

Why is everyone not thinking about this?

Spoiler

You'd think the talk wouldn't be stuck on humanoid-type mechs. But what about these?

[Foster]

Top-heavy unless gravity isn't a problem, like in shipyard EVA.

Then the feet are just wicked shock-absorbers with universal-clamps.

The knee-joint is vulnerable to small-arms fire.

And humans are actually pretty slow, the only redeeming quality is our ass (specificly, mine), which allow us to walk on two legs indefinately.

And making a hip-swaying sweet robot-ass is difficult.

[Sir Beowulf]

Hmm, then what about power suits?
Y'know, one-manned mech's that are a lot more smaller and focus on mobility and less on WMD's. They'd be a lot more maneuverable and even though they have less armor and weaponry, if you stuck one of these against a tank, I'd bet the suit would win.
Armored War Exoskeletons.

Also that mech totally has an ass. I'D TAP IT.
Pneumatic pistons.

This is pretty cool:
http://singularityhub.com/2012/08/04...on-mech-robot/