Proposal: Fractional Sublight Drive?

[OsakanOne]

Hey all.

At this point I think I kind of mislabelled the post. Its not a technology but a way of explaining the speed system.

I'm noticing we make a big deal out of the difference between the speeds a thing can reach in atmosphere, verses how quickly it goes in space. The SARP breaks down into what seem to be three neat brackets:

• Standard speeds, measured in mph/kph
• Fractional Sublight, which like 0.35c, 0.15c, etc
• Faster than Light (2,500c, 100c, etc)

If I'm not mistaken, some systems are used to weaken the friction space has, letting things go faster than 0.01c -- but its still the other big engines that do all the heavy lifting, just with less resistance letting the thing go faster: effectively playing hopscotch with space -- and more importantly, accelerate to those fractional sublight velocities VERY quickly.

In almost all cases, this cubed law game seems to have a theoretical ceiling, where the amount of energy invested stops giving you meaningful losses in spacial friction or spacial drag.

Depending on the quality of the device, you usually ceiling out somewhere around 0.356c. -- and if you're okay with having huge stress on your power systems that could destroy them and on your hull, you can overboost to something like 0.700c for a short time.

I'm also noticing that these systems usually don't work all that well in atmosphere -- or more specifically in conditions where there is an atmosphere (interfering with the system) and a huge amount of concentrated mass, which is why we don't seem to get terrorists using this technology as a luminal rod from god to pelt planets to death. This also applies in FTL: They just come to cold stops.

The alternative to making yourself "slippery" is technically not to move through space but to make space move through you, using bubbles of space and packet universes instead of compressions of space.

It helps to imagine yourself on a big coordinate chart with lots of numbers in all direction -- with every box filled with a number. All numbers affect all other numbers through a simple set of rules. When you compress space, you draw a big box around yourself with the rule "nothing outside affects anything inside", which is why these bubbles are inertialess (you are not in motion) and do offer limited protection from attacks.

What this box actually does is change the numbers in the boxes around its boarders. In doing so, your apparent location changes on the system because the coordinates which say "where you are" around your boarders have changed but the ones on the big world chart say you're elsewhere. Eventually the numbers around those numbers change. And the numbers around those numbers change. And thus, while you're not moving, you ARE travelling.

Now, here's where it gets interesting: there comes a point where the speed you can change your boarder numbers at isn't fast enough to go faster. Fractional lightspeed comes with one boarder of changed boxes around you in a pocket universe driven system. Post-C comes with more than one boarder.

I'm not sure if I'm making sense. But with some help, I would like to write a generic article explaining these three speed systems for new players, so they don't get confused and so they understand not only that there are theoretical ceilings but the constraints as to why they exist.

We can probably explain almost all the different sublight and light-speed propulsion systems using these kinds of metaphors and produce a lot of easy to understand explanations for the generics.


Thoughts?

 

[Wes]

If I get what you're suggesting, then some Yamatai ships are already doing that by using their combined field system for sub-c movement. The reason why this is preferable to using their aether engines is because there's no inertial forces to deal with, since the ship is changing position but not experiencing acceleration.

 

[Fred]

It doesn't make much sense. As I see it the analog was always "rocket thrust", "warp speed", "teleport somewhere else with a in-transit delay".
At the same time it looks like it resembles the way I wanted it to work on my upcoming ship:

First, you have the thrusters. Maneuvering thrusters, and the main thrusters that "make you go". Fusion rockets, aether plasma thrusters, and etc. Those wouldn't be measured in light-fractions because they wouldn't have speeds that would be that significant. I don't have the number for the top speed, but it'd be above 28 157.5 km/h (7.8 km/s - Mach 22), which is the speed you need to breakaway from Earth's gravity. This is my base figure, but it probably needs to be higher to account for breaking away from planets with more than 1G of gravity and rotation speeds different than Earth's.

Second, there's the inertialess drive - which usually goes by the name "gravimetric drive" on my ships. That's what I want to use to justify any 'slipperyness'. Sure, there'd be a degree of neko-like anti-grav 'falling in a direction' possible all on its own... but I wanted to have the thrusters play a larger role in propulsion to greater speeds (as in, fractional inertialessness). On one hand, the thrusters would be able to move the ship more since the grav drive would amplify their effect, and on the other hand the grav drive would allow the ship to ignore the usual constraints of acceleration and move much, much more quickly (not ignoring that acceleration exists normally, but giving a viable sci-fi way to cheat without obsoleting the thruster impulse propulsion).

What I want, once a ship is in the vicinity of planets, is to give them a mean of traveling to said planet that would take a bit and render obstacles in space more significant. I want a degree of speed which makes the existence of railguns firing at much lower c-fractions (Mass Effect railguns travel at 4025 km/s) viable, and being able to deliver devastating damage on impact. I want to see sublight torpedoes toned down to things that can be feasibly seen coming and shot at. I want directed energy weaponry to remain king as far as accuracy goes thanks to the amazing delay-to-impact they'd offer by comparison.

I like the idea of FTL jumps (as executed in the Miharu plot), or micro-fold jumps (as execute in Wes' plots), but I want to restrain it to fractional-c. Traveling for a second at .3c is like blinking from one location to another 100 000 km away in just a second. That's one-fourth of the distance between Earth and Luna. That ought be be largely enough in-setting to reposition oneself and avoid big bad amounts of firepower like a shock array being about to discharge your way. It'd be like, when you're getting closer to a planet, you don't get to be able to use 0.3c speeds, which would largely be intraplanetary, rather than transorbital, and you'd have to slow down to get over to the planet. Slowing down by how much is what's in the air for me, because what works narratively for Earth doesn't work as well in Jupiter's Hill Sphere. I figure it'd get to be partial .3c slipperiness the closer you get. Or it could be as simple as a power efficiency concern, but...

Between getting in an Hill Sphere and being in combat and needing to have your gravimetric drive generate a graviton barrier to protect your ship, it'd be mostly on your 'normal' thrusters to move your ship. Any feathering of extra slipperyness to have the ship withstand greater acceleration - a 'high-energy maneuver' - would allow greater nimbleness and movement for lower graviton barrier protection. A tactical jump - going to .3c for a second - would probably carry the risk of the defenses going next to nil as the ship prepares to execute the jump, jumps, and then recover/restores the defenses.

Third is actual FTL. Wes likes his Fold teleportations. I don't mind calling it 'fold', but as far as visuals go I want to go more in the direction of fold as demonstrated in Macross Frontier and as warp speed is presented in newStar Trek Into Darkness or in Prime Star Trek (as Slipstream). An extreme example of 'slipperyness', you jump point to point and you're in a 'tunnel' - I also tie in fold drives to distorsion-type shielding. With you in the tunnel are the other ships that jumped along with you in hyperspace - if you extended to have tagalongs. While combat would typically be unfeasible since there's little room to maneuver, ships being to the same relative speed and distance in the tunnel - with the variance being the thrusters speeds - would be able to do a limited amount of combat (not actually FTL combat, more like "in-FTL-transit-combat") with distorsion shields non-functional (since they're maintaining the 'tunnel') in the meantime - offering possible combat scenario like... when we take down the Lucifer in the last mission of FreeSpace. However, any significant amount of maneuvering or damage would risk 'slipping' out of the tunnel and get forced back into normal space; much like it happened when the Vengeance caught up with the Enterprise in ST ID.

* * *

The above, the way I see it, doesn't fix how space travel in-between systems is so uber-fast in SARP, but in a way it still helps travelling be significant because it establishes star systems as still being big places. With this model, I could have a ship ascend from a planet using its thruster engines, then pick up speed slightly once in-orbit to finally break it and go at full o.3c speeds. 1/3 of the speed of light can go around pretty well in our Solar system - going from Earth to Pluto (at trip of 29 AU at the shortest, depending on their orbits) could take a minimum of 11.6 hours for a ship with a 'fast' STL drive. There's your space travel.

This doesn't prevent ships from leaving an orbit and folding from planet to planet to save these hours of travel times. I mean, Wes does it, and I don't want to make it seem implausible to the point of retcon, which will never catch. But perhaps more like it'd be "swatting a fly with a cannonball". We've tried constraints such as charge times for the fold drive before, but they're not very well adhered to. Ships just fold out nilly willy. Energy constraints could come into play, but again, with aetheric power supplies, that doesn't seem relevant. So, to me, maybe it'd be more a matter of why Star Trek ships usually travel at Warp 6, and go to Warp 9 in emergencies. Power expenditure is one thing, but nebulous. Man hours required for maintenance is another much more credible concern (after all, militaries usually operate in emergencies, or are on important business justifying the logistics of maintaining a frequently used piece of equipment - but it might not be the same in the civilian sector and how a military could use thier fold drives could sometime be considered an "emergency fold jump" for civilians because of the wear-and-tear and the possibility for breakdown due to lower-spec equipment). There may be also the concern of stealth - in sci-fi like Macross Frontier, fold/defolds phenomenon are very visible. It might be a good plan for a squadron of ships to fold in separately to keep their defold signature on arrival smaller, and perhaps make sure that their defold is behind an obstacle (planet?) relative to their intended opponents. Then they'd be able to maneuver via sublight to more discreetly engage.

Also, since the above theme for propulsion involves the use of thrusters much more, it implies that fuel is being used as well. I'm not suggesting we track fuel usage, mind, but that it can create considerations when designing ships - ships equipped with matter collection systems can drop by nebulae and gas giants to harvest materials needed to refuel - we have the systems but rarely show use of them when they could actually be a pretty important feature of long-range vessels. Other ships without hydrogen/matter collection systems by contrast (i.e.: the Chiaki escort destroyer) prove a lot more dependent on fleet logistics/resupply points.

For civilian ships, they'd typically have to cover the fuel bill, or invest in an MCS and sit tight for several hours resupplying their fuel storage at select destinations. Odds are that in-system, some civilian travelers could prefer to pay/wait for refueling and travel between planets at sublight... rather than pay for a fold-capable ship (the Chiaki is not a fold-capable ship so it'd be cheaper to produce) or pay for the steep upkeep of a frequently-used fold drive.

All of this was stuff I've been mulling about for a good long while, ever since Wes said he wanted to make fold the primary mean of FTL rather than dividing it between fold drive and CDD. He gave up on that notion; I didn't, and I plan at least to deliver it in my own plot and see if it works as proof of concept. Once I've ironed out the kinks, anyways.