Hyperdrive

This Five Earths information can be used as a jumping off point for hyperdrives.
The hyperdrive works by traveling through any of several alternate dimensions called 'hyperspaces', where distances are shorter, or where points in normal space don't always correspond to the same points in that hyperspace, but this lack-of-correspondence happens in a predictable and useful fashion. Not all of these hyperspaces are safe for human use, however, without the development of appropriate defensive measures (and even then, another hyperspace might be preferable). (In an Infinite Worlds campaign, a Parachronic Engineer would note unnerving similarities between hyperspace engines and projectors, and sub-quantum conveyer or projector systems. Either might be converted into the other with sufficient effort, and the skills involved should default to each other at no worse than -4.)
==Dieselpunk-Earth Hyperspace==
The preferred hyperspace of the Dieselpunk-Earth universe, at least among humans and near-humans, is a smaller universe than normal space, but is more-or-less coterminous with it, and is mathematically 'close' to normal space, to the point that large gravitational fields in normal space extend into this hyperspace. Vessels may be violently pulled out of (or intentionally leave) this hyperspace by traveling close enough to a large mass in normal space to be pulled out by interaction with the gravity field (but preferably not so close as to collide with anything). Along with the aforementioned gravitational effects, this space has a number of other hazards, including hyperspace 'storms' (generally of an electromagnetic and/or psionic nature) lasting anywhere from minutes to centuries, various lifeforms and thoughtforms that may or may not be native, clouds of gas, particles, and/or plasma, various objects (not limited to abandoned spacecraft or space stations, though these are common), and sensor distortions that can make detecting other vessels and stations beyond human-visual range difficult (though gravity fields large enough to pull a vessel out of this hyperspace are very rarely obscured at such ranges - the larger (stronger) the gravity field, the easier it is to detect). Many of these natural hazards are taken advantage of by smugglers, fugitives, and refugees, as well as space pirates and privateers.
==Hyperdrive 'engines'==
===Up to TL 9===
* At TL9 or below, a hyperdrive 'engine' is more like a projector or cannon, as it doesn't fit inside any vessel small enough to be sent into hyperspace by it (being at least as large, and often larger, than the vessel itself, and not scaling down very well), and so 'pushes' the vessel into hyperspace, while itself remaining stationary (so to speak) in normal space, with no further connection that vessel. Depending on the design, the strength of the generators and cooling systems, and the mass of the next projectile, the projector may need anywhere from seconds to days to charge up, cool down, and/or be put through routine diagnostics and maintenance before sending another object into hyperspace. The only methods of leaving hyperspace available for most of TL9 are an equally-large 'normal-space projector' suspended in hyperspace in or near the target system, or a close approach to a large gravity field (which requires a more rugged vessel, and can be unpleasant for the crew: Roll HT-1 or worse, depending on design, to avoid nausea and other ill effects; on a critical failure, roll for unconsciousness against HT-5 or worse).
The often one-way nature of hyperspace travel at TL9 leads many civilizations to send out explorers in large fleets, rather than small flights or single vessels, with each craft carrying a few components of one or more pre-fabricated hyperspace projectors, to be assembled at the destination. Less wealthy nations, or those less inclined to invest that wealth in extra-system travel & colonization, might instead send out a vessel or vessels with detailed plans for the construction of the projector, and only those components that would be especially difficult to produce in situ with the vessel's space-mining and 3d printing systems. More paranoid star-states, like the Cythereans, fearing their technology might fall into alien hands, will first send out fleets with no data nor experts on hyperspace projectors, but much military expertise and armament, and only send the projector-parts and experts after the new system is deemed secure (which may be quite some time, for civilizations that lack FTL communications).
Many civilizations at this level will place unmanned astrogation beacons in hyperspace along well-mapped routes, to assist in avoiding hazards. Pirates and privateers, as well as military commerce raiders, will sometimes modify, move, or destroy such beacons, an act which is by itself often considered a crime against civilization.
===TL 9 - early TL 10===
Later in TL9 or in early TL10, launching boosters and braking pulsers become available. These single-use devices are portable projectors designed to bring the vessel into hyperspace from normal space, and vice versa, at the price of burning out after use (and sometimes exploding). The size of the projector is generally small enough for a vessel to carry two to four, usually outside the main hull; early examples may be so large as to be stacked like the boosters of chemical rockets. Pirates and military forces sometimes equip braking pulsers with manoeuver engines and forced-docking clamps, to drive target vessels into normal space. It is possible to use a launching booster to leave a hyperspace, or a braking pulser to enter it, but this is not as safe, comfortable, or efficient (treat it basically the same as being pulled out of hyperspace by a gravity well; also, roll the skill of the designer or manufacturer - on a critical failure ONLY, the vessel ends up in the wrong hyperspace, rather than in normal space or the intended hyperspace).
Average apparent speed (from the perspective of departure and arrival points in normal space) tends to develop from light-years per month (or months per light-year) to light-years per week, as a civilization progresses through TL9. This is due to a combination of the power of the sub-light engines, the sophistication of the vessel's computers, and the durability of the vessel, allowing it to survive hyperspace hazards that it otherwise would need to manoeuver around. A few civilizations develop travel speeds significantly faster or slower than average, due to differing technologies and mindsets.
TL9 Hyperspace communication, when non-psionic, tends to involve shooting something through hyperspace to the destination, to be intercepted by either a gravity field, or if your aim is good enough, a normal-space projector. Most vessels carry a 'small' projector the size of a large room, capable of projecting a mass of up to twenty kilograms (usually a fair bit less), and equipped with a railgun or similar accelerating device. The projectile will tend to be a rocket-drone with maneouver engines and a strong transmitter, though if the vessel has a high confidence of hitting the aperture or antenna of the receiving normal-space projector, an unguided 'bullet' might be used, or another medium, such as a maser or a heavy-particle beam.
===TL 10===
* At TL10, reusable hyperdrive engines generally become portable enough to be carried with the vessel into hyperspace, though the first, experimental engines of this type might appear near the end of TL9. Most races do not use hyperdrive projectors as engines until the system can project at least twice its own mass/volume into hyperspace, so as to have sufficient mass & volume for everything else a vessel needs. Because hyperspace motivators do not scale down well at this TL (the smaller the hyperdrive system, the larger it generally needs to be in comparison to the total mass/volume being sent or taken into hyperspace), this also limits how small a hyperdriven vessel can be: The smallest 'practical' reusable hyperdrive motivator produced by the Ssoranthhu (Ice Warriors) of Mars, for example, is about the size of a London city bus (but much heavier) - 9.5 metres long (SM+4), 2.3 metres wide, and 4.2 metres tall, massing 21.3 metric tonnes, and able to take its own mass & volume, plus about 30% more, into and out of hyperspace. These motivators are used for long-range probes, and sometimes automated couriers, almost never for inhabited vessels (and even then, any passengers are generally in suspended animation, and there are no crew).
Launching boosters and braking pulsers tend to shrink fairly rapidly over the course of TL10, especially before reusable hyperspace engines become small enough to be considered practical. Again looking to the Ssoranthhu for an example, the smallest disposable hyperdrive motivators they have are the size of a two-litre bottle, and can push an escape pod or small shuttle the size of the Crew Dragon capsule into or out of hyperspace.
Sensors capable of scanning hyperspace from normal space, or vice-versa, tend to become available late in this TL, or early in the next. These work well for detecting spacecraft or very large amounts of energy, not so much for communication without a projector of some kind. The earliest examples will often be too large to be carried on most spacecraft, and have relatively poor resolution.
Average apparent speed ranges from light-years per week to light-years per day.
===TL 11===
* TL11 hyperdrives are progressively smaller compared to the mass/volume they can translate into a hyperspace, and 'hyperspace stabilizer systems' are developed which allow vessels to become somewhat resistant to being forced out of hyperspace by gravity (that is, they require a higher level of gravity to force them out), while the systems are working. Starfighters capable of independent hyperspace travel (without needing launching boosters or braking pulsers) often become common during this TL.
Sensors capable of scanning hyperspace from normal space, or vice-versa, can become quite small at this TL, to the point that late TL11 or early TL12 sensors may be something you could carry in a pocket. This also greatly facilitates communication between hyperspace and normal space, including the use of the hyperspace beacon network for effective FTL communications.
Average apparent speed ranges from light-years per day to light-years per hour.
===TL 12===
* By TL12, the hyperdrive may be a negligible percentage of the vessel's mass and volume, though most hyperdrives are larger than they strictly need to be, in order to provide a certain robustness. The smallest known hyperdrive at TL12 (or possibly higher) is a few mililitres in volume, but can carry a large human in bulky armour to and from hyperspace, safely.
Hyperspace sensors and communications at this TL can be about as easy as the internet and cellphone network on Earth in the twenty-first century.
Average apparent speed at TL12 generally begins at light-years per hour, but the upper limit is unknown.
==Other Hyperspaces==
There are a number of other hyperspaces that this article will not cover in as much detail, such as the hyperspace discovered by the Kryptonian vessel Event Horizon, which is sometimes called 'the Warp' by humans, for its resemblance to the hyperspace described in a popular RPG from Infopunk Earth (Warhammer 40,000), that has made a little headway on the other Earths, in various forms. Few races are at all inclined to make use of this hyperspace, but some do stumble on it by accident, either in early experiments like the Kryptonians, or due to hyperdrive malfunctions. The faulty hyperdrive design on the Rigellian Pnen'th'x Corporation's worst marketing failure, the Ar'kez't Fnal'g ('Blue Harvest')-class medium freighter, was particularly prone to this, leading to the class's nickname/unofficial motto: 'Horror Beyond Imagination'.
One hyperspace used by fairly advanced cultures (TL11+) is quite similar to the hyperspace of Douglas Adams' Hitchhiker's Guide to the Galaxy: very fast, but uncomfortable for most biological life to travel through, being described as 'unpleasantly like being drunk' - when asked how being drunk is unpleasant, the questioner is advised to ask a glass of water.
Hyperdrive is the easiest method of FTL travel available in the known parts of the Dieselpuk Earth universe (that is to say, the parts of it astronomically near Sol). This is not true in the Infopunk Earth universe, as the only hyperspaces available there are similar to the one called 'the Warp' - indeed, there is some evidence that one such hyperspace is the same one, allowing an indirect, though terribly hazardous, connection between the Earth One and Earth Two universes. Hyperspaces are difficult to access, or may not even be connected, in the Steampunk, Clockpunk, and Fantasy Earth universes.
==Skill and use==
Skill: Astrogation (specific Hyperspace)/TL (IQ/Hard for most hyperspaces, IQ/Very Hard for particularly confusing hyperspaces, such as the one Inp-Earth calls 'the Warp'; hyperspaces straightforward enough for an IQ/Average skill exist, but are too slow, difficult to access, or both, to be commonly used)
Prerequisite: Astronomy of the same TL.
No Default (normally; at GM's discretion, some Hyperspaces may be similar enough to each other to allow defaults between them).
The required specialization for the preferred hyperspace is called '(Hyperspace: Standard)', while that for the hell-like hyperspace is called '(Hyperspace: the Warp)'.
Specific routes in most hyperspaces may be bought as techniques, but cannot exceed Astrogation+5; base penalty varies from route to route; stable, well-mapped routes, particularly those with several astrogation beacons, may have a base bonus, rather than a penalty, though this bonus may not exceed Astrogation+2. Astrogators may specialize by region of space.
(Yes, I am aware that it's called 'Navigation' in 4e. The setting's themes dictate the alternate name.)
==Hyperspace Route Penalties==
===Route Type Table===
Roll 3d
3: Exceptionally good route; Astrogation+2
4-5: Stable and/or well-marked route; Astrogation+1
6-15: Normal route, see below.
16-17: Hazardous route, see below.
18: Impassable route, see below.
Normal and hazardous routes have penalties varying based on distance. For a route less than ten light-years long, roll 1d-3, and treat any result greater than 0 as 0: thus, a roll of 2 is -1, and a roll of 1 is -2, but 3 or higher is 0. For every ten light-years, add a further -1, and roll again (e.g. a route covering 32 light-years would have a minimum penalty of -3, and you would roll 1d-3 three times, for a maximum penalty of -9). Alternatively, of course, the GM may set the penalty to whatever best fits the game; some regions are safer or more dangerous than others, and hyperspace conditions do change from time to time, both due to changes in local gravity wells (e.g. a start going nova), and due to interactions within hyperspace itself.
Hazardous routes pass through or too near hyperspace 'storms,' gravitic anomalies, plasma clouds, and other such dangers, and/or have a high frequency of pirate attacks; specify one or more hazards per such route. Assume a base penalty of -3 to start with, then roll 1d-3 as above. 
An 'impassable' route is one in which existing hazards are sufficiently problematic as to interdict travel at your tech level, rather than literally being impossible to pass through.
Category:Spaceship Components
Category:Five Earths