The most famous example of gravtech, and among the first applications of gravity technology. An amalgamation of various applications of gravity technology, built by the same Tiberius Crohn, combining to allow interplanetary and interstellar flight:
A contragravity envelope to isolate the ship from external g-force.
Artificial gravity to steer and give the crew something to walk on.
A gravcomm unit to allow for FTL in-system communication
An array of flash-channels to twist the universe within the ship’s drive envelope - kicking it up into the metadimensions and back down again.
Mechanism
Two layers of directional contragravity facing inside and outside the ship, with artificial gravity channels layered in key directions between. This setup creates an envelope of gravity-nullifying space around and within the spaceship, and manipulates gravity between the fields to ‘drop’ the vessel in any direction the channels are arranged. This allows the ship to move at sub-light speeds around the system, and at the gravitational step eventually escape the bonds of luminal space altogether.
The pilot flies the ship by determining the angle of hull gravity and firing the reaction engines if necessary - both pushing and ‘pulling’ the ship in the direction they want to go. So flying a starship is a very different experience from piloting a ground, air or even grav vehicle.
Whilst at speed, the ship’s internal contragravity envelope effectively eliminates any inconvenient time dilations or uncomfortable acceleration effects. This process is not perfect however; the ‘reaction time’ of these systems, particularly to sudden changes in direction or velocity, plus the subtle but permeable vibrations these systems give off as they are forced to work harder at higher speeds, can cause what most refer to as ‘space-sickness’ in the unseasoned. This is most noticeable in drillspace because of the vast forces acting on the ship at all times.
Speed Limits
Crohn particles are more resistant to interference closer to the origin of a gravitational mass, but become less charged and therefore more pliable the further away they get from it. Practically, this means that gravity speeds are capped fairly harshly when just above a world's surface, but get faster and faster the further away a ship gets from a planet or any other stellar masses - with a rare theoretical limit, based on "perfect" solar circumstances and spike drive, of just under the speed of light.
- Tip: There is a known 'sweet spot', when passing through the zone where a mass’s gravity lessens and the star’s gravity becomes the most significant pull, in which the multiple forces clashing within the crohn particles make them much easier to manipulate into artificial gravity - allowing the ship to effectively gain a burst of speed. This is the reason why pilots will often go out of their way to ‘surf’ close to planets or other large objects on the way to their destination.
Ship to Ship Combat
If a starship’s weapons are hooked up to their spike drive, which they would be by standard, then interplanetary speeds become no obstacle to combat. It is extremely easy for a hostile ship to just follow and aim their fire into a fast-moving ship’s contragravity wake and score some easy hits. Evasive manoeuvring just isn’t an option at such speeds either, even the tiny delay between the sudden change in direction and the contragravity compensating would obliterate anybody inside.
All this means that, if a pursuing ship gets close enough to its target to fire into its wake, the target is forced to either just take the damage or drop out of near-FTL speeds and engage in local combat.
Entering Drillspace
Crohn particles are at their most malleable when free from any major gravitational influence, and it is here where the spike drive can achieve its most amazing effect. A burst of power to the spike drive, consuming a significant quantity of fuel, channelled through an array of flash-channels, allows gravitic twisting of the universal substrate within the ship’s contragravity envelope - driving the ship “upward” through a spectrum of dimensional frequencies. The ship effectively vanishes from mundane, “luminal” space and is thrust into the metadimensions, where vast energy currents and formless masses increase the speed of light and propel a ship at speeds impossible in the mundane universe. To enter drillspace, a ship must be either at an appropriate jump point or a star system's drill point.
Jump points are far enough away from other gravity signatures to enter 'shallow drillspace', where the ship doesn't entirely vanish from mundane space but where they can still achieve far greater speeds. Such 'minor jumps' are often used to cross large orbital gaps between worlds, and to more quickly navigate the sector's larger star systems.
Drill points, however, are a vast distance away from a star, often at the very edge of the system, where crohn particles are almost inactive - the ship can be driven upwards through the metadimensional frequencies and fully into drillspace. Suitably massive objects such as stars cast a “shadow” into these deeper metadimensions, forming both navigational beacons and anchor-points that enable transit up and down the dimensional spectrum. So long as a spike drive had a star to launch from and a star to bring it down, it could ride the metadimensional currents in a headlong rush of superluminal speed. This is the only known method of interstellar travel.
Either way, how far and how fast the ship can travel in this state depends on the rating of the spike drive. If the contragravity envelope fails in "drillspace" then the ship is instantly obliterated by the currents - and better drives can maintain their envelopes for longer whilst riding the waves harder.
How it Looks
When flown well, spike drive ships move and turn very smoothly along their trajectories. Aerodynamics are useful in faster ships designed for in-atmosphere travel, as contragravity doesn't protect at all from air-friction, but not necessary - the ship will not drop out of the sky regardless of how slow its flight. Apart from this the only visual impact of their movements will come from firing the reaction-fuel engines, or from the way that light is effected by speed and gravity.
Contragravity Effects
When the contragravity fields are active, an asymmetrical shimmer can be seen around the ship’s edges - barely noticeable at planetary speeds but becoming more pronounced the faster this ship goes. This is slight but noticeable in the direction of travel, but more pronounced behind as the crohn particles - pushed aside by contragravity - realign along the ship’s “gravitational wake”.
Inside the Ship
From inside the ship the visual impact is exponentially more dramatic. Planetary speeds cause no visible difference, but as the ship approaches the speed of light images of the outside universe become compressed toward the axis of motion - seemingly stretching the cosmos in either direction. Light from ahead becomes “blue-shifted” toward more energetic frequencies, while light from behind becomes “red-shifted” down the spectrum.
In Drillspace
On jumping into drillspace, the gravitational twisting appears as a rapid ‘bending’ of the ship’s profile - in whichever direction the ship’s flash-channels are aligned - before the ship simply seems to ‘snap’ out of existence. This effect is simply reversed from inside the ship, with the exterior stars seeming to suddenly bend or group before simply vanishing.
In drillspace itself, the ship along with all wavelengths of light are swept along by the metadimensional energies. Here, light travels faster than the ship, but only in the same direction. This means that most of the view is the pitch black of invisibility straight ahead and all around, except for the bright white of combined light directly behind. Through both spectrums frequent surges of random colour or massive shadows are also visible as the various luminal wavelengths are deflected unpredictably by any changes in the vast currents. These are often what a pilot must interpret during transit, if they start to see light or colour appearring directly ahead then they must adjust the ship’s course to avoid disaster.
For more information about how the spike drive operates, see
Starships.
