Interstellar propulsion is an integral part of starships. Engines provide the force that drives the ship on those wild, history-making adventures. Trillions of credits have been poured into the field of study that focuses on astro-based kinetics, all geared toward making an object get from point A to point B faster, safer, and more efficiently.
Without getting wildly in-depth into the mechanisms of these engines, we'll attempt to illustrate the principles behind them. Technology has made leaps and bounds since 2003, enough to demand that each type of engine have its own scientific field of study. Although a run of the mill repair shop engineer would have a broad, generalized understanding of these engines, it would take a specialist to perform any type of significant repairs, modifications, or upgrades.
Astropropulsion as a science is extremely fluidic. With experimental designs being concoted almost daily, it would not be wholly uncommon to find ships tooling around with test engines. Even so, there still remains a consistent set of well-propagated types that have proven themselves on the mass market.
Sub-Light Speed Edit
James C. Maxwell, physicist, discovered in 1873 that light reflected in a mirror exerted minor pressure on the mirror. He didn't know what conclusions to make at the time, but that evidence would later be combined with others to establish the third law of light: that it has mass. However miniscule, the pressure exerted by a photon could be theoretically harnessed to propel a spacecraft. It would eliminate the need to carry fuel, clearing up many logistics and allowing for a smaller, less expensive craft.
Nathaniel E. Hermann, U.S. Navy engineer, created the first starsail-driven spaceship in 2177. It was huge. The USS Nautilus's starsail, nothing more than a reinforced piece of cloth teathered by cables, measured almost half a mile across. It experienced appreciable acceleration (1.13 m/s^3) until space junk ripped it apart twenty minutes into the test.
Modern vessels have a better version of the starsail. Through a more innovative design, multiple cutting edge layers allow for the same level of acceleration with a relatively small size, around five to ten meters in width. Starsails are usually found as a form of backup propulsion in deep space exploration ships. They can be unfurled within a matter of minutes.
The Deep Space 1, a Mars exploration sattelite, was launched from Earth in 1998. It was the first vessel to use ion propulsion as a means of getting around. Using large amounts of electricity, an atom could be coaxed to ionize (to gain an electron, in this case), superaccelerated, and shot out the back by an electromagnet.
The expulsion of the ion from the starship exerts an equal and opposite force (according to Newton's law), which happens to be the direction that the ship wants to move in. While a single ion yields almost no experiencable movement, millions of these ions shot out in phase allows a mild rate of acceleration.
Ion engines have comparatively slow accelerations, faster only to starsails, but a high maximum velocity. With time, a spacecraft with an ion engine can achieve speeds rivalling other forms of engines. It also offers competitive value; a base model will run about 2,500cr more than an electromagnetic drive.
Because engines with faster accelerations allocate less time for an ion to be sped up, the rate of acceleration and maximum speed are inversely dependent. There are three forms of well-used atoms in order of increasing acceleration and decreasing maximum speed, argon, xenon, and radon.
A starship operating an ion engine under maximum power is said to leave a monochromatic trail of gas behind it that slowly dissipates over time. A bright emission analogous to the flame from a rocket engine can also be seen.
Gravitic drives represent the first mainstream starship engine that relys on previously-thought hypothetical subatomic particles. Through the generation and indirect control of gravitons, gluons, ane mesons, a gravitic drive manipulates the vessel's inherent gravity field, making it asymmetrical. The disproportionate mass is affected by the background push-pull of the universe and shuffled toward the direction of asymmetry.
The side effects of a gravitic drive are countered by advances in superstructure technology. The asymmetry generated by an active gravitic drive applies great stresses on the hull of the ship. Up until the twenty-fifth century, polymer engineering was not advanced enough to tolerate these forces, and structural shielding in the form of gluons and mesons hadn't been thought of.
The gravitic drive is sometimes colloquially referred to as the gravitric drive. The origin of this nickname is uncertain; it is speculated that the addition of the extra 'r' serves to make the concept sound "better."
The gravitic drive is the mainstay choice in the universe. It falls under the middle of most spectrums, modest price, decent acceleration, and acceptable maximum velocity. Its scalability makes it well-suited for a variety of ships. A gravitic drive has an invisible effect.
A diametric drive uses negative matter to achieve propulsion without the need for a reaction mass. It juxtaposes a positive and negative mass in such a way that the negative mass always pulls toward the positive mass. This method creates a local gradient (an inclinating slope within space-time itself) that accelerates the ship. Powerful, localized electricial charges must be maintained to keep the negative mass from becoming unstable during operation.
The major drawback to the diametric drive is its constant need for maintenance and repair. Understanding of negative mass is sketchy at best, and it is this lack of understanding that makes the diametric drive prone to breakdown; the negative mass keeps on destabilizing. Although it has been speculated that the Centauran government has made breakthroughs in this field, no solution to this problem has been forthcoming.
Nevertheless, a diametric engine creates a powerful forward force that allows an approximate 10% increase in speed over the gravitic drive. Its effect is invisible.
A disjunction engine creates a cogent point-gravity well by propagating billions of gravitons on and within itself. A large mass, separated from the source by a reinforced barrier, is pulled toward the gravity well. The barrier prevents the mass from getting to the source, creating a slope and mini-gradient propulsive force within the vessel that propels the ship in the direction that the mass wants to move.
The disjunction drive, like the diametric drive and starsail engine, is reactionless. Because of the law of conservation of momentum and energy, the forward velocity (directly related to kinetic energy) is directly proportional to the amount of energy in the form of electricity imparted on the graviton generator. This concept is what allows a disjunction drive-equipped starship to effectively adjust speed.
Space jockeys have held a tradition of pushing their disjunction drive beyond the proscribed limitations established by the manufacturer. While there would be no immediate side effect, extended use will result in (a) degradation of graviton emitter and (b) breakdown of the barrier.
A base model disjunction drive to full power is 20% more powerful in both maximum velocity and acceleration than a gravitic drive. Its effect is invisible.
A tachyon drive works on the same principle as an ion drive, except that it shoots tachyons and not ions out the exhaust port. Tachyons are subatomic particles that go beyond the speed of light.
Using massive amounts of electricity, the tachyon drive captures free-floating tachyons that exist in the universe and directs them in phase. The force of the expulsion generates an equal and opposite force that pushes the ship forward. Because tachyons travel at superluminal speeds, the resultant forward force is great.
A standard tachyon drive is 30% more fast than a gravitic drive. Its effect is invisible.
All matter has a direct antimatter correlation (a position to an electron, for example). When matter and antimatter come together, they explode violently. The antimatter drive uses matter-antimatter annihilation to create a shower of subatomic particles that are ejected out the rear of the ship at relativistic speeds.
This mechanism is similar to a matter-antimatter powerplant, although it uses the raw energy as a propellant rather than converting it into usable electricity. Specialized antimatter reactor/engine combinations may use a hybrid reactor that also doubles as an engine.
Although these particles move at speeds slower than tachyons, the explosion generates significantly more particles than a tachyon emitter, allowing for a maximum acceleration and speed that is significantly faster than a tachyon drive.
Phased gamma emission from the drive makes it appear bright to anybody directly behind the ship. An invisible side effect is a stream of lethal radiation in the form of photons that populate most portions of the electromagnetic spectrum. The emission from an antimatter drive makes it easily traceable.
The following drives are usually known within certain scientific circles. They are largely experimental and in varying stages of development.
During the first few nanoseconds of an electromagnet charging up, the electromagnet experiences very high frequency vibrations because it is in a non-steady state. This curious condition, now called the Goodwin phenomenon after the eventual inventor of electromagnetic propulsion, was simply acknowledged and ignored. It wasn't until 2007 that NASA looked to this vibration as a source of propulsion.
Two or more extremely powerful magnetic plates are placed in phase at the rear of the spacecraft. An electric current is passed through them, and the electromagnets charge and form a field of influence. It is then that a foreign source of magnetic emissions, usually a niobium-tin plate, is introduced near the two plates. An asymmetry is caused in the magnetic field; as the foreign source is pulsed with electricity, it coaxes the main electromagnets to vibrate as if they were being recharged.
When in sync, the electromagnets will vibrate in only one direction, forcing the ship in the opposite motion (proven again through our good friend Newton).
Level of development: Prototype Edit
- Findings: Pulsations degrade electromagnets at alarming rates. Sustained operation at a factor of .75 from desired levels result in breakdown within two hours. Microfractures along the axis of fixation are observed. Without further study into the possibilities of artificial structural reinforcement through elementary particle generation (esp. meson), electromagnetic drives have improbable market viability.
- Velocity and Acceleration: Expected. Faster than gravitic drive, slower than xenon ion drive.
In the 1960s, Robert Brussard, a physicist at the United States Los Alamos National Laboratory, dreamed up of a hypothetical engine that sucked in rarefied hydrogen in space, supercompressed them, and used a laser to coax a fusion reaction from them within a reinforced chamber. The reaction generates forward thrust as thermal energy is pushed out from the exhaust of the drive. Technical limitations prevented him from creating a design.
In the year 3001, Sanctuary Engineering Services working in collaboration with graduate students from the Libertyville School of Engineering is attempting to revitalize Brussard's attempt that failed more than a millennium before. They envision a ramjet engine that would replace the relatively bulky starsail as a secondary and emergency form of propulsion. There is even an attempt to create a powerplant version of the Brussard ramjet.
Unfortunately, with the destruction of Sanctuary in 3003 and the subsequent loss of its research facilities, the ramjet project has been stalled. No third party developer has expressed an interest in continuing the endeavor.
Level of development: Design, stalled Edit
- Findings: When operated in a nebula or other gas-dense anomaly, an active ramjet engine could generate thrust equal or exceeding current specifications for starsail. A passive ramjet engine moving at speeds equal to 3000hms will theoretically absorb sufficient hydrogen to maintain velocity without a net energy loss.
- Velocity and Acceleration: Unspecified
Faster-Than-Light Speed Edit
One of the two contemporary FTL drives available for use on starships, spindrive technology is based on "classic" hyperspace theory, and was the first successfull attempt to create an artificial equivalent to Otherspace-traversing FTL.
Contrary to what one might expect, however, a spindrive does not actually propel the ship forward. Rather, its two rotating nacelles generate a graviton field by orbiting each other at high speeds. Once sufficient velocity has been achieved, the graviton field "disconnects" from normal space, creating its own miniature universe. Free from Newtonian and Eisteinian confines, the ship's normal sublight engines then propel this graviton bubble at incredible speeds relative to normal space. The disconnect from normal space also prevents time dilation.
The dangers of spindrives lie in the fickleness of the artificial field surrounding the ship during FTL speeds. Even minor mechanical or calculatory flaws can spell disaster, as there is no telling where the ship will revert to normal space. If anything happens to the drive, power supply or the FTL computer systems, the ship could pop back up anywhere. This is similar to known Otherspace malfunctions, such as the one that caused the displacement of Vanguard vessels from Val Shohob to Kreton, demonstrating that both drives work along the same lines.
Moebius Drive Edit
The other contemporary technology available for FTL travel, Moebius drives operate on the same principle and technology that caused the Moebius Effect. On the surface, a Moebius drive seems to be similar to a hyperspace drive, insofar as it shunts the ship into a quasi-spatial universe wherein it then travels to its destination. However, this is not quite correct.
Moebius Space, for one thing, does not share bilateral spatial relations with this universe; that is, it is not a "sub-dimension" or a universe "below" ours, where distances are compressed and can thus be traversed faster. Rather, Moebius space is a 0-dimensional space: all spatio-temporal points in our universe are the same point in Moebius space. This means that essentially, travel through Moebius Space could be instantaneous; however, such instantaneous travel would mean foregoing the safety measures that ensure that the ship's spatio-temporal and quantum alignments are the same after the jump as they were before. In other words, the danger inherent in using Moebius Drives lies not in not reaching the point of destination, but in the side-effects of reaching it by way of passing through Moebius Space without sufficient safety measures. Such side-effects include quantum dislocation, spatio-temporal and/or dimensional disjuncts (such as the large-scale disjunct that caused the Sol System to switch with its extradimensional equivalent), and a variety of other interesting but usually lethal consequences.
Tinkering with the speed with which the the ship is returned from its Moebius-induced 'possibility haze' state is greatly discouraged, and usually not done. (When the upside of gaining a few minutes of reduced travel time comes with the downside of being turned into protoplasmic goo upon returning from Moebius Space, very few captains and engineers, no matter their pride in their skill, choose to play around with their Moebius Drive.)
Otherspace Drive Edit
Operating on techno-mystic principles rather than scientific ones, Otherspace Drives were the mainstay of FTL vessels until the annihilation of the Kamir and Hivers at Nocturn in 3002. After that, FTL travel was limited to system-to-system jumps utilizing Castori-operated jumpgates before the introduction of aforementioned Spin and Moebius Drive systems.
Despite being called Otherspace "Drives", there was little these means of FTL travel had in common with a starship engine. A knobby black orb on a pedestal that, when active, coruscated with blue light, OS drives required the direct interaction of a Hiver to operate. The principle behind this technology was never satisfactorilly explained, though it is surmised that the Hiver directly removed the ship from Normalspace, and used the far-reaching presence of the Hive Mind to navigate the ship through Otherspace, eventually pulling it back out into Normalspace upon reaching the destination.
"Otherspace" itself was -- or rather, is the knife edge of time and space, a region of hyper-spatiotemporal existence on the verge of all possibilities, the seam that forms the virtual border of the multiverse. If a ship goes off course in OtherSpace, it may end up lost in time and space - possibly even trapped in an alien universe. All instances of Otherspace drives are now defunct and have been replaced with contemporary technology.