Potential Pitfalls for a Superscience Technology

[Varyon]

So, I've been working on a possible Space Opera-ish setting to make use of GURPS Spaceships. There are two major superscience technologies - a system that accesses subspace to make a force screen, and one that accesses hyperspace to dump velocity (theoretically allowing a vessel to expend all its delta-V during travel, then "brake" at the end of the journey, rather than having to save half of it to decelerate near the end). We'll refer to these technologies as the Shield and the K-Sink, respectively. One of the big issues with these is that they don't cost any energy to maintain - the Shield relies on its link to subspace, the K-Sink on the very energy it's dumping into hyperspace.
EDIT: I should note here the purpose of this thread - tear my superscience devices apart! Tell me everything that's wrong with them, what sorts of unexpected uses they may be employable for, and so forth. This should allow me to modify them later to function in a way that doesn't destroy the setting.

One of the limiters on the Shield is that it generates an excessive amount of waste heat. So much so that, in a spaceship, it actually requires a full system (meaning it takes up 2 systems total) for heat circulation and venting. This actually only allows the Shield to be active for about 15 minutes before its safeties kick in and shut it down (overriding the safeties risks serious damage to the Shield starting at 16 minutes). Fuel Tanks full of coolant extend this by 15 minutes per tank. Disabling/destroying the circulation/venting system (which includes the main radiators) drops this to 3 minutes (and only 1.5/tank). This is all in the vacuum of space, of course - in an atmosphere it would be able to dump heat more quickly. I'm assuming being in a Standard atmosphere would be about equivalent to having an additional full tank of coolant (the Shield actually blocks some of the heat energy from escaping, which is one of the reasons it overheats so quickly).
The problem here is that the Shield is generating an excessive amount of waste heat... with no energy input (well, technically the energy comes from subspace...). This could be used as a way to generate "free" energy. I think I'm actually OK with this - the way the shield works you'd have to work in atmosphere, and you'd probably end up turning it on, waiting until it reaches its maximum safe temperature, turning it off, then running the coolant through some sort of heat engine to cool it down and generating some electricity in the process. The Shield itself is rather unkind to matter (think the DR Device from Ender's Game, but slower and without as much propagation), meaning you'd need to move it around from time to time as it reduces the ground it sits on to a fine powder. I think this would end up generating energy at a rate that isn't too far off from a solar panel array of comparable mass on a clear day - although the Shield would be able to generate this energy in any weather.
Am I missing any serious issues here? The setting tends to be rather environmentally friendly (so no fission energy or the like), so one problem I see from this potentially green energy source is an excessive amount of heat pollution.

The other issue is with the K-Sink. The K-Sink functions first by establishing a "K-Tether" to nearby objects. After this point, the pilot of the K-Sink-equipped ship can accelerate (at 100G for a full-sized system) without expending delta-V, but only in a direction that will make the ship's velocity relative to a K-Tethered object closer to 0. For most objects, the K-Tethered object gets an equal-and-opposite change to momentum (so if an SM+5 ship has tethered an SM+7 ship and is decelerating at 100G, the SM+7 ship, which is 100x as massive, would decelerate relative to the smaller ship at 1G). Neither ship "feels" any acceleration (just like with a pseudo-velocity drive, except this is causing a real change). A ship must be relatively close to an object to K-Tether it (it's a function of mass-based SM - that SM+5 ship can K-Tether Earth's sun at around 1 AU, can K-Tether Earth at 1.2 million miles, or could K-Tether that SM+7 ship at around 700 yards), and K-Tethering larger objects is much easier than smaller objects (I haven't completely decided on the numbers, but Sun/Earth would be an automatic success, an object 2 SM larger would require a roll against 12, an object 2 SM smaller would require a roll against 8). I'm considering having certain objects (planets, stars, maybe some moons) qualify as "celestial bodies" and be immune to the mutual-acceleration clause, but those objects are probably so much larger than any ship that it probably doesn't matter.
The above is all fine and well, but it introduces an odd possibility - K-Sinks are effectively contragravity devices! This would allow zero-cost (aside from maintenance) geosynchronous orbits at any height, provided it's within K-Tether range. What sort of effect would this have on a society, and on its industry? Additionally, this introduces the possibility of yet more "free" energy - activate the K-Sink, move the K-Sink up (easy with no gravity), then deactivate the K-Sink. Gravity will try to pull the object back down, and you can turn this energy into electricity with a simple turbine system. This is going to be much more efficient than the Shield-based generator... is there any good way to tweak things so something like this won't work? I was thinking maybe having the K-Sink's temperature drop as it gets further away from the K-Tethered object (turning heat energy into potential energy), but that would be hard to implement. Perhaps I should make K-Sinks all-or-nothing? That is, either they are decelerating at their full rate (again, 100G for a full system), or they aren't working at all. I think this would work - it's just as difficult to get something to a given height, but then you can turn on the K-Sink and it'll stay there (you'll need acceleration in excess of the K-Sink's to make it move). Of course, one use I wanted for the K-Sink was to make it easier for ships to Rendezvous with each other, and with all-or-nothing K-Sinks this might not be as feasible...

[Nereidalbel]

All that thermal energy from the Shield could be used to produce molten salt, which can then be used to boil water and drive turbines. Since molten salt can safely reach 1,000 degrees Fahrenheit, you can dump a lot of heat energy into it, and thus, boil a lot of water.

The K-Sink could be resolved by requiring some minimum acceleration for the tether to remain stable.

[Varyon]

Originally Posted by Nereidalbel

All that thermal energy from the Shield could be used to produce molten salt, which can then be used to boil water and drive turbines. Since molten salt can safely reach 1,000 degrees Fahrenheit, you can dump a lot of heat energy into it, and thus, boil a lot of water.

I haven't bothered to define the temperature at which the Shield will shut down, but, yes, I imagine using it to boil water and drive turbines would be one potential heat engine one could use to generate electricity.
I suppose we could set the shut-down temperature for the Shield by determining the rate of electricity generation by a given weight of TL10 solar panels in full sunlight, set this as the rate at which the same mass of Shield generator+coolant can generate electricity, then back-calculate using Carnot's theorem (while TL10 heat engines probably aren't at maximum efficiency, I'd imagine they're close enough to get a ballpark temperature).

Originally Posted by Nereidalbel

The K-Sink could be resolved by requiring some minimum acceleration for the tether to remain stable.

I think I jumped the gun a bit with the K-Sink problem. See, I was assuming it would just negate gravity, then you'd be able to move it without a problem. Instead, it constantly accelerates (at whatever rate the pilot sets, up to its maximum) in a direction that will set relative velocity to 0. This will mean that when it's "negating" Earth gravity, it's actually accelerating at 1G (or more, if the pilot so desires), so it would be just as hard to move (up or down) as it normally would be to move up. So, no free energy from the K-Sink.

...

I think my initial post failed to convey the purpose of this thread - I want to know what sorts of problems (like the infinite-energy K-Sink system I proposed earlier) exists with the technologies as I've presented them, so that I can adjust the way they work properly (or perhaps find a new use for them).

[Walrus]

For Shield.

What's the size of Shield-producing device? Do they vary? Can it be arranged easily depending on needs? How does heat yield depend on the size of device?

What's the particular effect of Shielding? Is it some sort of "Force Field", "Utter Dome" or what?

For K-Sink.
What about accelerating towards far planets (or sun) and then back towards closer planets, effectively going back and forth and generating that free energy and moving just from the surface? How fast can be that switching arranged?

What about using it as tunneling device (or potential bomb) when you accelerate toward the object on the opposite site of a planet (which may be again giant planet which just happened to be there)?

[Varyon]

Originally Posted by Walrus

For Shield.

What's the size of Shield-producing device? Do they vary? Can it be arranged easily depending on needs? How does heat yield depend on the size of device?

What's the particular effect of Shielding? Is it some sort of "Force Field", "Utter Dome" or what?

The generator weighs 1/20th (1 system) of the vessel, and must be in the dead center. It creates a shapeable field just above the vessel's surface. Interestingly, this effect seems more mass-based than volume-based.

Its effect is multilayered. First, it breaks molecular bonds (or, rather, makes it such that molecular bonds don't exist at the Shield surface). This effect is transmitted through matter a short distance (the more dense the matter, the further it transmits) but is not self-sustaining.
Secondly, it actively blocks energy and particles from crossing the barrier. Rather large particles (that is, objects) can force their way through, but will find their outer layers stripped off in most cases. Game mechanically, the shield makes a roll against 17 to block any incoming object/attack. If the object's SM is equal to the vessel's SM -4, this is instead a roll against 16. If the object is -3, the roll is against 15, and so on - meaning you're at 12 to block something of equal SM, and get no roll (skill 2) if it is 10 SM's larger. There will also be an effect of speed (higher speed means higher probability of intercept), although I haven't worked that out yet.
Shields are two-way, but are unstable and constantly "flickering." 1 minute after activation, your ship's computers have successfully analyzed the flicker (it follows a unique pattern each time the Shield is activated) and thus only allows your weapons to fire during a flicker. It's possible to analyze an enemy ship's pattern to be able to fire when it flickers (imposing a skill penalty on the intercept roll), but you cannot capitalize on this when your own shield is active.
In general, you can't manage larger (they'd overheat immediately, regardless of amount of coolant) or smaller (the shield would destroy your vessel) shield generators. The only exception are Blades - a monoplanar Shield using a special generator, Blades can cut through other Shields but don't project very far.

Originally Posted by Walrus

For K-Sink.
What about accelerating towards far planets (or sun) and then back towards closer planets, effectively going back and forth and generating that free energy and moving just from the surface? How fast can be that switching arranged?

I think I see what you're getting at, maybe. Something like setting your velocity relative to the Sun to 0 so you're moving fast (about 18.5 mps) relative to the Earth, then dumping your velocity by setting Earth as your tether. Seems difficult to exploit, really.

Originally Posted by Walrus

What about using it as tunneling device (or potential bomb) when you accelerate toward the object on the opposite site of a planet (which may be again giant planet which just happened to be there)?

You can only tether to something that is within a range set by 3+(Vessel SM)+(Target SM). For an SM+5 vessel, this is +54 (1.2 million miles) for Earth, +65 (1 AU) for the Sun. This could allow you to slam into earth at a rate of 18.5 mps using the Sun as your reference. You'll cause some damage, but probably not a lot unless you're massive. For massive vessels that could cause significant damage at such a speed, it would probably be illegal to get within close enough range to be able to do this without being intercepted.

[Walrus]

You use a lot of narrow game mechanics (particulary Spaceships) in explanations but thread seems to discuss more in-world effects of such technology.

So, again about Shield. How little can it be? How fast it can be switched on and off? What is it's effect against visible light and pure energy weapons (lasers)? What about sound waves?

And that effect of breaking molecular bonds. Do you mean intermolecular forces (so, forces bonds molecules which effectively turns molecular solids and liquids into very fine powders/sprays) or chemical bonds? The latter will cause decomposed atoms to react quickly after leaving zone of effect generating a lot of heat as well on the border of shield. The former doesn't determine what it does to atomic or mettalic lattice. And even without that it would generate heat as well, though not so much.


And one solution to shields. We can assume that shield technology generator requires actually low temperatures (maybe it requires superconductors or something like that) and a lot of low-temperature coolant, so practical usage of that excessive heat is impossible.

it would probably be illegal to get within close enough range to be able to do this without being intercepted

I mean actual weapons, something like kinetic orbital weapon with good positioning and nearly instant acceleration. They don't need permission or whatever.

And about that non-inertial acceleration. What is the size of that non-inertial zone? What if we can shoot out weight on a cord just before tehthering so that it leaves the zone of lack of inertia. We can see interesting effects then.