FTL 'Fuel' [Space]

[David Johnston2]

The insane power requirement issue is why I went with the sundivers. Somehow by flying at suns at high speed and skimming the sun's corona the starships draw the needed power since I can't really see them holding enough "fuel" internally to do it.

[Ulzgoroth]

Specific FTL fuel never really makes sense to me. I can't really imagine an FTL process being directly concerned with chemistry, and have little patience with the fantasy minerals that softer SF often will invent. FTL fuel that you mine is right out.

I could possibly see antimatter (as the best available way of generating an intense gamma flux perhaps?), or some type of FTL 'charges' that contain one use machinery or 'machinery' for an FTL operation. Mostly I just lean to no FTL-specific consumables (aside from maybe specific spares).

[PTTG]

The hardest-science FTL fuel I can imagine using is something like exotic matter. It could be that establishing any wormhole requires the consumption of EM, and the equipment for manufacturing or creating more of it cannot feasibly be moved. Maybe it's only made on Io by an ancient alien manufacturing complex drawing antimatter out of the Io-Jove flux tube.

Alternatively, it could be that it requires a packet of entangled particles kept at absolute zero and manufactured at the destination system. Then it's an interesting twist on fuel, as you would need to obtain more of these particles if you wish to return there without paying someone else to get you more.

[Black Leviathan]

Jump Gates in Fading Suns require a purchased fuel but the original books were very vague about the mechanics of that other than the amount of jumps each ship had capacity for. We interpreted it as vessels requiring reaction mass to fly through the gates as reactionless drives cause insanity or attract things from the dark of the voide! We made the jump fuel essentially a treated heavy water that allowed ships to push themselves through the gate to the other side.

[warellis]

Originally Posted by PTTG

The hardest-science FTL fuel I can imagine using is something like exotic matter. It could be that establishing any wormhole requires the consumption of EM, and the equipment for manufacturing or creating more of it cannot feasibly be moved. Maybe it's only made on Io by an ancient alien manufacturing complex drawing antimatter out of the Io-Jove flux tube.

Alternatively, it could be that it requires a packet of entangled particles kept at absolute zero and manufactured at the destination system. Then it's an interesting twist on fuel, as you would need to obtain more of these particles if you wish to return there without paying someone else to get you more.

So something like negmat, like what one guy used for their homebrew Traveller setting as a reason for why ship electronics, like computers, were so big and clunky compared to modern stuff?:
The Starship Example: "Reactionless" Drive?
The Starship Example: FTL, Stargates, and Rabbitholes
Building A Space Navy in the Gentleman Abroad Series 1

Spoiler:  

Down the Rabbithole (Traveller/Cepheus Engine version)

Basic Assumptions: Space travel is made possible by the use of stabilized negative matter. Most modern transport technology is based on its use. “Natural” or pure negative matter is nearly impossible to use, due to its properties of energy amplification. If pure negative matter is exposed to energy – any energy, even a single photon – it will amplify its energy until everything is vaporized. Over time, the artificial intelligence known as the Janoi developed permutations of negative matter that were more stable and could be utilized with sufficient containment. Two main permutations exist: Negamat, a stabilized solid used for anti-gravity, and NegMat, a metastable fluid used in reaction drives and to travel between stars.

Despite its staggering utility, negative matter has one drawback that has so far not been overcome: Computers, beyond a certain level of complexity, cannot function in close proximity to negative matter. While it is possible to use some electronics around Negamat and NegMat, these systems are clunky and primitive, using CRT screens and magnetic tapes. The nearly unlimited intellect of the Janoi gave humanity the stars, but they cannot use their own creation.

Tech Level: The manufacture of negative matter requires a TL 15 industrial base. However due to the effects of the Negative Matter, computers and other electronics above TL 9 will cease to function.

Interplanetary Travel: NegMat is used to propel a spacecraft as a pseudo-reactionless drive. The performance of such a drive, in game terms, is identical to the performance of a standard Maneuver drive. Tables for interplanetary travel times may be found on page 104 of the Cepheus Engine System Reference Document.

Overdrive: A starship (as opposed to a small craft) may accelerate up to one Maneuver number higher than its given Drive rating by pumping its reserve NegMat from its bow tanks aft. The spacecraft may only accelerate up to M +1, however, as the net acceleration force is canceled out by the anti-gravity effects of the NegMat. When the net gravity effect reaches 0g, the pumps begin to fail and the spacecraft must decelerate.

Travel Times: Because interstellar travel does not use Jump Drive in this system, it is not necessary to travel one hundred planetary diameters from a world in order to travel between the stars. That being said, interstellar travel is only possible with certain special circumstances, detailed below:

Interstellar Travel: Interstellar travel can be accomplished in one of two ways. First, there is a network of stable wormholes held open with negative matter in a series of linked stargates, while the second requires scouting out and opening naturally occurring wormholes found in the deep gravity wells of stars and some gas gaints.

Janus Gates: The Janus are the stargates created by the Janoi and is where the super-intelligent AI that manufacture them got their name. Travel through a Janus is instantaneous. Janus gates confirm to the following conventions:

· Gates only allow travel between two given points in space.

· Gates are usually located far apart in a given system as they create close, space-like curves. Usually, gates are located in the stellar/planetary LaGrange points of a star system’s planets, with the most commonly traveled gates in the orbit of the most heavily settled planet or the largest gas giant.

· Any spacecraft may travel through a Janus – even small craft.

· A Janus may be projected through another Janus in order to extend the network farther from a Nexus system. This would establish a direct route from the terminal system to the Nexus system. In actual practice, such “express” gates are not established until the terminal system is heavily settled and the frontier has moved several systems beyond.

“Rabbitholes”: Starships (Ships over 100 dtons that are specially equipped with NegMat Projectors) can use naturally occurring wormholes found where deep gravity wells have caused microfissures in the fabric of spacetime. These “Rabbitholes” allow passage to virtually any system at the cost of expending NegMat. Rabbitholes confirm to the following conventions:

· Rabbitholes cannot be opened between systems that are connected by Janus gates. The relativistic effects of closed space-like curves make any attempt to open a Rabbithole fail and the NegMat used in the attempt is lost.

· Rabbitholes are constantly moving as the spin and orbit of stars drag spacetime in constant motion. Even if a Rabbithole between two systems has been used before, a starship’s Navigator must search for it each time it is used. The Navigator must Throw 8+ to find a particular Rabbithole around an average sized star, 10+ around a dwarf star, and 12+ around a gas giant. Modifiers include the relevant computer programs (The equivalent of Jump or Jump Tape) and the skill of the Navigator.

· For convenience, assume that a starship’s “Rabbit Ears”, or NegMat Projectors, displace the same tonnage as a Jump Drive of the same rating. As an example, a 100dton starship capable of opening a Rabbithole between stars two parsecs away would have a Projector displacement equal to a Jump Drive A. The relevant tables are found on pages 122 and 123 of the Cepheus Engine System Reference Document.

· A starship will expend an amount of NegMat equal to one quarter the amount of fuel an equivalent Jump Drive would consume. For example, a 100 dton starship traveling two parsecs via Rabbithole would expend 5 dtons of NegMat. (0.1 x ship’s tonnage x distance in parsecs/4)

· Starports and Refueling: Negative matter costs 2000Cr a displacement ton, is only manufactured in Nexus Systems, and only Class A ports have an unlimited supply. In addition, only systems with a Class A port may create and place new Janus gates. Class B ports typically have a secure supply of NegMat, provided by a Janus direct from a Nexus system. Class C ports have repair facilities and can provide fuel for power plants, but NegMat must be special ordered. It will take 2D days for the ordered NegMat to arrive and cost 2,500Cr a dton. Class D and E starports are as described in the Cepheus Engine System Reference Document

[Johnny1A.2]

In my world, FTL is semi-dependent on an extra-dimensional form of exotic matter that was the basis of the legendary orichalcum of Plato. It's not indispensable, but it's far, far harder without it. It's not a fuel as such, though, it's a component. It doesn't get used up. FTL isn't its only application, and it's super-rare and awesomely expensive, though, which shapes the entire setting.

[Rupert]

Originally Posted by Fred Brackin

Civilian ships used giant closed-cycle fuel cells to power the stutterwarp. in addition to the "charge" thing you had to get rid of in a solar graviity well.

So while you were discharging your fTL you put out solar panels to run your fuel cells in reverse and turn all their previous water exhaust back into hydrogen and oxygen.

That's not something I recall from the Traveller 2300 or 2300 AD rules at all. Fuel Cells (and MHD plants) used fuel, and then it was gone. There may have been some rules for collecting the waste water and cracking it later, but it certainly wasn't a standard procedure, and just about any ship that needed the freedom from refuelling would just use a fission or fusion plant.

[Fred Brackin]

Originally Posted by Rupert

That's not something I recall from the Traveller 2300 or 2300 AD rules at all. Fuel Cells (and MHD plants) used fuel, and then it was gone. There may have been some rules for collecting the waste water and cracking it later, but it certainly wasn't a standard procedure, and just about any ship that needed the freedom from refuelling would just use a fission or fusion plant.

<shrug> My memory is quite clear but I think it was a very early version. I know thye renamed the game at one point but I only got the one book (alsmot certainly the first one) for it.

[Prince Charon]

Psionic, chi-based, or other 'pretty much magical' FTL drives can potentially have some pretty disturbing 'fuels.' On the safe end, 'you have to sacrifice a live chicken to Damballa every jump' isn't too onerous, and wouldn't be morally problematic for most people, you just need to keep a good supply of live chickens onboard (and white rum, which apparently he really likes). On the other end, sacrifices of sapient beings, or vessels that are somehow powered by a forsaken child (who might die from the strain, or become useless when they grow up, or something like that) would be really hard to justify a non-evil society going along with (unless they don't know about it).

[Varyon]

Originally Posted by Prince Charon

Psionic, chi-based, or other 'pretty much magical' FTL drives can potentially have some pretty disturbing 'fuels.' On the safe end, 'you have to sacrifice a live chicken to Damballa every jump' isn't too onerous, and wouldn't be morally problematic for most people, you just need to keep a good supply of live chickens onboard (and white rum, which apparently he really likes). On the other end, sacrifices of sapient beings, or vessels that are somehow powered by a forsaken child (who might die from the strain, or become useless when they grow up, or something like that) would be really hard to justify a non-evil society going along with (unless they don't know about it).

An idea I had for a short story was that FTL (and other superscience, but the story was to focus on the FTL bit) required a person as a "battery" of sorts, and it drained away the time they had left to live. A twist was, this drained from human nominal lifespan of 120 years, and if the person reached their "cut-off" date, they'd simply expire on the spot (similar to those who run out of time in In Time). Many people were willing to sell a few years they probably wouldn't get anyway, and of course plenty of people sold far more than a few years. Criminals could also reduce their sentences by donating some of their time to live (essentially trading in potential time at the end of their lives to get more time now). Certainly has a lot of room for corruption, but as the loss was voluntary, it didn't require an evil society to make use of it.