[Spaceships] Developing a tech paradigm for space-opera adventure

[Michael Thayne]

Setting premise: at some point in the setting's background, humanity gets its hands on a limited supply of alien superscience. Think alien artifacts buried on Mars, or a badly damaged alien probe blundering through the Sol system, something like that. Basically a handwave to justify a small amount of superscience while keeping mostly near-future tech.

The key piece of technology humanity manages to reverse-engineer from the aliens is the force screen. This has some important spin-offs, particularly because it means powerful fusion tech can be contained much more effectively. This manifests as the Plasma Torch (from Spaceships 7), as well as miniaturized fusion. Reactionless drives remain out of reach, and the only FTL (if any?) comes in the form of alien jump gates that humans haven't been able to reverse-engineer yet.

The space combat paradigm works like this: in all cases, use the tactical combat rules. However, there are still two distinct "modes" of engagement. One uses the 20 second / 10 mile tactical combat scale. These are considered "knife fight" engagements, though they still take place at tens or hundreds of miles. In these engagements, Plasma Torches are usually fired in the high-thrust, low efficiency mode, and kinetic weapons play a key role. In order to make railgun shells more worthwhile on this scale, I'm going to houserule them to have a velocity of 3 mps (which is what they originally had when Spaceships was published, pre-errata).

The other mode is the long-range laser duel, using the 3 minute / 100 mile tactical combat scale. These engagements generally happen at at least 500 miles, but usually not more than 3000 miles, because (1) lasers more powerful than 30 GJ are not available and (2) the ships involved typically have enough armor that lasers are not useful beyond the 1/2D range. At these long ranges, kinetic weapons are little used. Shells are almost totally useless against targets with any ability to maneuver at all (GM may declare they automatically miss), and if a missile or ramming attack is attempted, combat should briefly shift to the 20 second / 10 mile scale to resolve this, which is likely to be advantageous for the defender.

Thoughts on this basic setup? Some specific questions I have:

1. Should human-built force screens have less DR than standard TL11^ ones? On the one hand, halving DR would keep DR in line with other TL9 tech. On the other hand, force screens can be overcome anyway with concentrated fire or high-velocity projectiles, and full-power force screens might encourage more "up close and personal" combat.
2. Should stealth in space be boosted? Again this might help make space combat more up-close and personal. OTOH I don't accidentally want to make detection ranges sometimes drop below 10 miles, that would be too close.
3. Super-fusion reactors: yes or no?
4. Edit: should I use the "Armor and Volume" optional rule from Pyramid #3/34?
5. Edit 2: what force screen variants should I allow—or even make standard for free? Aside from cloaking (which falls under "stealth", above), I think the ones I'm most likely to use are Adjustable and/or Hardened.

[Fred Brackin]

Originally Posted by Michael Thayne

Sr.

Thoughts on this basic setup? Some specific questions I have:

1. Should human-built force screens have less DR than standard TL11^ ones? On the one hand, halving DR would keep DR in line with other TL9 tech. On the other hand, force screens can be overcome anyway with concentrated fire or high-velocity projectiles, and full-power force screens might encourage more "up close and personal" combat.
2. Should stealth in space be boosted? Again this might help make space combat more up-close and personal. OTOH I don't accidentally want to make detection ranges sometimes drop below 10 miles, that would be too close.
3. Super-fusion reactors: yes or no?

I can tell you that at TL10 without Force Screens combat is very much "eggshells with hammers" time. If you want slugging matches keep the force screens at full. At worst you'll empower nuclear warheads on missiles.

By default here is little stealth in Spaceships and there probably won't be any with your plasma rockets. Unless you put double special cloaking devices it's gonna be a non-issue.

The fusion reactors aren't a big deal. With out drives that eat power points those are all going into weapons and shields and power points aren't likely to be your limiting factor.

[Michael Thayne]

Originally Posted by Fred Brackin

I can tell you that at TL10 without Force Screens combat is very much "eggshells with hammers" time. If you want slugging matches keep the force screens at full. At worst you'll empower nuclear warheads on missiles.

At TL11-12, a Heavy Force Screen can provide approximately 4x the DR of a single armor system of the best available material—and the force screen covers the entire hull, not just one hull section. If you change the comparison to the best armor available at TL9 (advanced metallic laminate) vs. a TL11 Heavy Force Screen, now the force screen is 10x better. This is balanced by the force screen being vastly more expensive... but even so 10x, for all hull sections, seems like it might be a bit excessive? It's probably not a huge deal either way, since a force screen can potentially be brought down quickly by concentrating fire from many lasers (or even maybe a single rapid-fire laser) on a single ship, but I was interested in people's input.

That reminds me of another question I edited into the OP: should I use the "Armor by Volume" rule from that one Alternate GURPS issue of Pyramid? Could result in some ships having almost impenetrable armor vs. lasers... though that particular issue is mitigated somewhat by being able to target weak points in armor.

By default here is little stealth in Spaceships and there probably won't be any with your plasma rockets. Unless you put double special cloaking devices it's gonna be a non-issue.

Yeah, cloaking devices—or the cloaking option for force screens, to keep with the setting's theme—are one way of boosting stealth. Another option is the boosts to stealth in Pyramid #3/94. That's what I was asking about in the OP. I'm a bit worried though about those options being too good, though. Like I think in theory those options could result in small ships with weak sensor arrays failing to see each other at 10 miles.

The fusion reactors aren't a big deal. With out drives that eat power points those are all going into weapons and shields and power points aren't likely to be your limiting factor.

Spinal batteries and force screens are both pretty big power munchers. Part of what I'm thinking about is how they're going to be powered on smaller ships: do I waive the rule that TL9 fusion reactors can only be used on SM+10 or larger vessels? Or do I allow super-fusion reactors and more or less require them on small ships, in spite of how expensive they are? Might limit use of chemical power plants because they really should not have the long endurance they do under RAW.

[Kallatari]

Originally Posted by Michael Thayne

Should human-built force screens have less DR than standard TL11^ ones? On the one hand, halving DR would keep DR in line with other TL9 tech. On the other hand, force screens can be overcome anyway with concentrated fire or high-velocity projectiles, and full-power force screens might encourage more "up close and personal" combat.

Have you considered mixing both options. Force Shields are high energy options, meaning they require a Power Point assigned to them to work.

So perhaps the TL9 and TL10 shields (if any) are not as energy efficient as the mature TL11 shields. Humans got some of that alien tech to work, but not perfectly. A TL9 shield requires 3 Power Points to get the full DR of TL11 (and respectively gets 1/3 or 2/3 if it is only assigned 1 or 2 Power Points), while a TL10 shields require 2 Power Points (with 1 Power Point giving it 1/2 the DR of TL11).

The recharge rate can also be 10% of the current setting per second as well. So you could keep a low shield, then max out the power for a couple turns to have it recharge much more quickly.. although granted this doesn't do much with respect to the length of a space combat turn. But could have an effect if for some reason a person is trying to shoot through with handheld firearms...

Anyway, with this energy efficiency issues, managing the shields becomes a question of managing where you want your power to go.

[AlexanderHowl]

A TL11^ Light Force Screen possesses 150 dDR (semi-ablative) for a SM+10 vehicle. A laser main battery for a SM+10 vehicle deals 6d×5 (2), an average of 105 damage with Armor Divisor /2. Even with the Force Sceen, an average of 30 dHP of damage will penetrate per hit, which will also reduce dDR by 10, meaning that it only prolongs the fight between two SM+10 destroyers. A SM+10 destroyer will also want Hardened Advanced Laminated Armor (and probably Heavy Screens), which will allow it is truly stay in the fight. Even so, two such spaceships, each with four main batteries, will tear each other apart in a few minutes at short range.

[Michael Thayne]

I think I'm leaning towards a "yes" on the armor and volume rules because it makes making the 1/2D range for lasers truly irrelevant. Otherwise there's the issue that even the most heavily armored ship can potentially have its armor penetrated by a spinal battery beyond the 1/2D range by attacking weak points in armor.

Another issue is what force screen variants to allow—or even make standard for free. Aside from cloaking (which is a separate issue), I think the ones I'm most likely to use are Adjustable and/or Hardened.

[Michael Thayne]

I think it might help to work out some basic designs. These are some very basic civilian designs that might be targeted by pirates or (if used by criminals) the space patrol. I'll post more designs later.

Spaceplane

SM+6 streamlined hull, winged. This design assumes craft smaller than SM+10 must use super-fusion reactors rather than regular fusion reactors. (Fission is ruled out by the danger of using fission in surface-to-orbit craft.) It can make it from Earth's surface to orbit on a single tank of fuel by alternating high and low thrust modes.

Front Hull
[1] Advanced Metallic Laminate Armor (dDR 5)
[2] Control Room (C5, Comm/sensor 4, 2 control stations)
[3-6] Passenger Seating (six seats each)

Central Hull
[1-6] Passenger Seating (six seats each)
[core] Cargo Hold (5 tons capacity)

Rear Hull
[1!] Plasma Torch Engine
[2-5] Passenger Seating (six seats each)
[6] Fuel Tank (5 tons hydrogen)
[core] Half-Sized Systems: one Super-Fusion Reactor (de-rated to provide one Power Point); one Cargo Hold (2.5 tons capacity)

Total Cost: $5.5M

Freighter

SM+11 unstreamlined hull.

Front Hull
[1] Smaller Systems (three at SM+10): one Control Room (C7, Comm/sensor 8, ten control stations); one Habitat (60 cabin-equivalents)
[2-6, core] Cargo Hold (1500 tons capacity each).

Central Hull
[1-6] Cargo Hold (1500 tons capacity each).

Rear Hull
[1] Smaller Systems (three at SM+10): one Advanced Metallic Laminate Armor (dDR 16); one Plasma Torch [!]; one Fission Reactor (provides one Power Point for Plasma Torch).
[2-6, core] Fuel Tanks (1500 tons hydrogen provide 15 mps delta-V each).

Total Cost: $460M

[Johnny1A.2]

Originally Posted by Michael Thayne

Setting premise: at some point in the setting's background, humanity gets its hands on a limited supply of alien superscience. Think alien artifacts buried on Mars, or a badly damaged alien probe blundering through the Sol system, something like that. Basically a handwave to justify a small amount of superscience while keeping mostly near-future tech.

The key piece of technology humanity manages to reverse-engineer from the aliens is the force screen. This has some important spin-offs, particularly because it means powerful fusion tech can be contained much more effectively. This manifests as the Plasma Torch (from Spaceships 7), as well as miniaturized fusion. Reactionless drives remain out of reach, and the only FTL (if any?) comes in the form of alien jump gates that humans haven't been able to reverse-engineer yet.

The space combat paradigm works like this: in all cases, use the tactical combat rules. However, there are still two distinct "modes" of engagement. One uses the 20 second / 10 mile tactical combat scale. These are considered "knife fight" engagements, though they still take place at tens or hundreds of miles. In these engagements, Plasma Torches are usually fired in the high-thrust, low efficiency mode, and kinetic weapons play a key role. In order to make railgun shells more worthwhile on this scale, I'm going to houserule them to have a velocity of 3 mps (which is what they originally had when Spaceships was published, pre-errata).

The other mode is the long-range laser duel, using the 3 minute / 100 mile tactical combat scale. These engagements generally happen at at least 500 miles, but usually not more than 3000 miles, because (1) lasers more powerful than 30 GJ are not available and (2) the ships involved typically have enough armor that lasers are not useful beyond the 1/2D range. At these long ranges, kinetic weapons are little used. Shells are almost totally useless against targets with any ability to maneuver at all (GM may declare they automatically miss), and if a missile or ramming attack is attempted, combat should briefly shift to the 20 second / 10 mile scale to resolve this, which is likely to be advantageous for the defender.

Thoughts on this basic setup? Some specific questions I have:[LIST=1][*]Should human-built force screens have less DR than standard TL11^ ones? On the one hand, halving DR would keep DR in line with other TL9 tech. On the other hand, force screens can be overcome anyway with concentrated fire or high-velocity projectiles, and full-power force screens might encourage more "up close and personal" combat.

For space opera style settings, you really need force screens or something to take their place. Otherwise, as Fred noted, it's eggshells and hammers.

Instead of limiting protective power, I'd make them unreliable. After all, you're implementing a higher-technology system on lower-technology materials and resources. Sometimes that's possible, sometimes it's not, but when it is it's usually kludgy and tricky.

(Could an atomic bomb have been built in 1890 or 1900, if the necessary information was available? Maybe. Just barely. It would have been huge and awesomely expensive and heavy and certainly unreliable. Attempts were made to implement automatically controlled fuel injection in cars using vacuum tube tech. It worked...but so unreliably as to be ineffectual. OTOH, some modern tech could have been fairly readily implemented earlier, if someone had just known how.)

Let's say your human-kludged shield generators are just as strong as the alien ones, but are 5x as massive, 3x as bulky, eat 3x as much power, and you have to do a maintenance roll every so many minutes of use, on a fail they conk out and on a critical fail they conk out catastrophically. That's the sort of thing that low-tech implementations can involve.

You might even have a dedicated specialist on your engineering crew who maintains the things and keeps them going in battle.

Something else: your kludged human-made superscience might require some hard-to-get ingredients. Imagine a Victorian-age engineer trying to lay hands on some rare-earth elements for his super-magnets, or working to strain out one isotope from another of some element in bulk.

What might you need? Well, maybe the shield generator needs quite a bit of livermorium-292 (half life 13 milliseconds). Maybe the alien tech includes a way to slow down the decay process, but you still have to make the stuff in the first place...

[Michael Thayne]

Thinking about it more, my big SM+11 freighter design doesn't make a great deal of sense, because so much time is spent drifting with the (very expensive) torch drive turned off. A more sensible system might involve tugs that look like this:

Tug

SM+6 Unstreamlined Hull

Front Hull
[1] Advanced Metallic Laminate Armor (dDR 5)
[2] External Clamp
[3] Control Room (C5, comm/sensor 4, 2 control stations)
[4-6] Fuel Tanks (1.5 tons hydrogen provides 20 mps delta-V each)
[core] Habitat (two cabins)

Central Hull
[1] Advanced Metallic Laminate Armor (dDR 5)
[2-6] Fuel Tanks (1.5 tons hydrogen provides 20 mps delta-V each)

Rear Hull
[1] Advanced Metallic Laminate Armor (dDR 5)
[2] Smaller Systems (three at SM+5): one Plasma Torch Engine [!]; one Fission Reactor (provides one Power Point for Plasma Torch Engine); one Fuel Tank (0.5 tons hydrogen provides 6.7 tons delta-V).
[3-6, core] Fuel Tanks (1.5 tons hydrogen provides 20 mps delta-V each).

Total cost: $2.34M

This has more than enough fuel to push a cargo barge from LEO to an Earth-Mars transfer orbit. This process takes many hours, so ships carry enough crew to allow rotated watches, and even sleeping if necessary. By themselves, of course, the barges are easy prey for pirates or commerce raiders, necessitating separate patrol ships.

[Michael Thayne]

When I say "space opera", I'm not particularly interested in slugging matches. To a large extent the thing I want is interesting space battles. A slow, repetitive slugging match is not necessarily interesting. But of course, neither is "launch nukes, everyone dies". Ideally, I'd like to find a balance point where a variety of tactics are viable, where there's some rock-paper-scissors or something like "combined arms" is the best approach.