Locus Candles and Foldspace

The Locus Candle Lattice (LCL), often just called Locus Candles is a huge matrix of satellites encompassing the entire Galaxy at a mean separation of 1000 ly. The matrix is 10,000 ly in height and 100,000 ly in width on each axis. The entire mesh therefore consists of roughly a hundred thousand satellites.

These satellites broadcast on a given (radio) frequency exact time and position enabling anyone with a mediocre radio and computer to position himself within the lattice, by using triangulation, with unprecedented accuracy.

The project was commissioned early in the GST era, some 60 thousand years before RTC and it took one and a half millennia to complete. Over the next 2-3 thousand years the signals, which travel at lightspeed, had been transmitted over enough distances to make the solution viable.

This system has proved incremental in the colonization of the Galaxy. It is free for all to use and not subject to any restrictions. It doesn’t matter whether you’re in an escape pod or commanding a battlecruiser, the locus candles make sure you know exactly where you are.

Locus candles are the cornerstone of interstellar space travel because they are indispensable for folspace travel. When a ship is going from point A to point B via foldspace the location of the ship and the exit point must be known with great certainty. If they are not the ship risks flying way off course, and even into a star.

A pilot must use Locus to triangulate his position as well as the exit point before entering foldspace. This requires that he is able to receive signals from locus candles however distant the exit point might be. If a pilot is going to travel 10 thousand light-years then he must be able to pick up signals from locus candles 10 thousand light-years away (and 10 thousand years old). Not all comms are good enough to accomplish that, and not all pilots able enough in astrogation and comm. Operation. If this proves too difficult the pilot can always elect to take several smaller jumps. This requires a little bit more time as locus triangulation can take from a few hours to a few days each jump.

The Locus signal contains a detailed gravitation map of the surrounding region which is the most important aspect of it from a foldspace perspective because the foldspace drive must know the exact gravity distribution at its exit point to calculate it effectively. But because the age of this map depends on the distance to the Locus Candle in question the validity of the map depends on the distance to the satellite. If a pilot receives a signal from a few dosen satellites at several distances he can build a gravitational map based on it and see if there are any variations over time. If there are then he might be able extrapolate an accurate map from the available data or simply take shorter jumps, which is a safer alternative.

Locus signals from inhabited systems are much more accurate than from the Locus Candle Lattice and provide a much better predictability as to the exit point configuration.

The reason why pilots can’t just use maps to plot the exit point is that it’s not enough to know the exact position and gravitational alignment of the exit point – The error during the exit procedure is very high and the trajectory deviation can be several light-years. The largest problem is that there is a great tendency for the opening to converge to any nearby mass and without an exit Locus anchor there is a 95-99% probability that the ship will exit inside a sun or a planet within 10-20 light-years of the intended exit point.

The folspace opening starts to form several hours before exit and the ship is able to communicate outside the opening in that time. During this time the pilot or navigation officer must locate the Locus candles they locked on during entry to be able to feed drift corrections into the foldspace drive. If the jump is longer than five thousand light-years the pilot must rely on Locus Maps to position exit anchors since it is possible that there are no visible candles close enough to the exit point to be useful. Note that the quality of maps vary considerably although maps of the four major conreces are virtually flawless.

If the pilot relies not on maps but on direct observational data instead (within 5000 ly) he must take into account that the satellites were accurate 5000 years ago and might not even be operational today, so it is a good idea to gather at least 10 anchors before entering foldspace (four is the absolute minimum and the ship risks exiting inside a sun if there are any fewer).

If a ship is close to exiting foldspace and the navigational array cannot find at least four Locus anchors the pilot can either use his own astrogation expertise to try and make it out in empty space (usually several light-years away from the intended destination) or he can lock on to a single Locus Candle and exit foldspace at its location. This method is much safer and once out the pilot can simply enter foldspace again towards his intended target as only entry information is required for such a short jump.

As the tunnel starts to open a few hours before exit ships at the destination are able to see the tunnel opening (this is particularly true for exits in inhabited systems where exit points are determined within a few thousand kilometers). They cannot determine the type of ship that is about to exit but they are able to determine its mass. This can be quite a good way to ambush ships while they are vulnerable. A defense strategy for this is to use Locus candles to exit foldspace a light-year or so from the system and then take a shorter jump the last leg. Using this method the tunnel opening starts to form only seconds before the ship emergence.

Ships can be outfitted with special folspace sensors to be able to pick up foldspace tunnel openings. With these it might even be possible to pick up if a tunnel opening is wildly off course, signifying that a pilot was unable to locate Locus anchors. It might be possible to send out a radio transmission to guide the ship but since the fluctuations are very erratic and cover many light-years it is quite unlikely that this would aid the struggling ship.

One of the reasons that in-system signals provide a better exit point (but only for entry into that specific system) is that the gravity wells surrounding the Locus satellite remain more constant in time because the satellite rotates with its star around the Galaxy. The Locus Candle Lattice remains fixed in space while the Galaxy rotates to provide for a more consistant frame of reference. The gravitational changes that result from this as star systems and globular clusters whiz by at several thousand km/hour can be easily extrapolated so the accuracy instability isn’t really a huge problem.

The Locus Candles maintain their position within the lattice by using on-board ion-drives, which counteract the gravitational pull of neighboring masses and the Galactic nucleus. The most common cause of Locus Candle decommission is that it’s thruster or navigational arrays have failed. In most major conreces there are regular maintenance checks on each Candle which makes sure it remains operational. These checks are usually carried out continuously and a cycle of one sector takes 5 years. In other conreces (Liren, Nordon, Realm for instance) there is little or no maintenance and the system is degrading. This makes Locus data in these regions unreliable and ships have to take shorter jumps to remain on track.

When ships are jumping less then a hundred light-years it is not necessary to gather Locus data from the exit point as the entry point data can be extrapolated without a lot of error. The error accumulates quickly, however, and each light-year after that adds to the risk. A very proficient pilot with good positional information regarding his entry point might make a successful jump up to a thousand light-years without exit point data while others might wind up as filling for a passing comet.

Because ships are slaves to good Locus positional information the best route between two systems isn’t always a straight line. This has caused the creation of trade routes, which have waypoints at relatively specific intervals where good locus signals are available. At these waypoints there have sprung up commercial depots where ships can dock for repairs, refuel, gambling and prostitutes.

These waypoints are also favorites of pirates but since the exit point of ships can vary by hundreds of light-years it’s a game of searching for a needle in a haystack.

If a pirate does get lucky then he can be sure there is no one anywhere around to receive his prey’s distress signal.

A pirate might also monitor his prey while entering foldspace and might deduce from that where he will emerge. A second ship moves to those coordinates for interception before the prey can exit foldspace.

There is only around 60-70% of Locus candles still operational. There are many spots in the Galaxy where the candles have long since been snuffed out. Their signals are of course still available for those far enough away so that the signals were emitted before it went off-line. These regions of space have become known as dark-zones and it can be perilous for ships without good pilots and communication equipment to enter these regions as they might have difficulty getting out again.

Inhabited star systems almost always have their own Locus signals which act as very accurate guides for incoming and outgoing ships. For commercial ships the upside is that they get a much better accuracy than with the locus candles and can exit foldspace at precisely the closest point possible to the system (Outer Marker). If using only Locus Candles the ship might have to spend an additional 2-10 days in NLS or risk coming too close to the star, being in grave danger of crashing directly into it. The downside for those of questionable morality is that these signals direct incoming ships into one of several shipping ports which are heavily monitored by customs and border control. This has caused many smugglers to try using only locus and either take the long way in or take a chance. Many ships have been lost in that way.

Another upside is that these shipping port zones often contain a space station or at the very least a fuel depot so that passing ships who only need fuel don’t need to enter the inner system, a trip that usually takes 10 days back and forth in NLS.

This is the general paradigm of foldspace travel. You need to know exactly your start and end point or your ship has a better chance of ending up in a random black hole than it does of reaching its destination.

This is the reason that nothing outside the Galaxy has been explored – Ships don’t have a definite exit point for their foldspace drives, something that can prove catastrophic. Because there is not a lot of mass outside the Galaxy ships can go into intergalactic space and make it back but the trip is usually arduous and not very fruitful. Before a hundred years ago no one had managed to reach either Magellan clouds and make it back despite numerous attempts.

The reason the Dilern Regime could reach the Galaxy from the Large Magellan Cloud is that they have a very similar system there, albeit not as sophisticated one. They managed to pick up Locus signals which traveled for 120 thousand years through intergalactic space. This coupled with their own positioning data gave them an entry and exit point.

Their own transmitters aren’t nearly as powerful as Locus but now that the Galactic Wormtunnel has been discovered ships can go through it to only 6000 ly from the LMC. From there they are able to access Dilernian Positioning data from 6000 years ago. This enables ships to go to the LMC now.

There is a huge project ongoing now to start a new Locus Lattice in the LMC since the Ivalieh invasion destroyed the Dilernian satellite cache. This project will take thousands of years and has faced some stiff political hurdles from the Dilern Regime.

A Locus Candle is an unmanned satellite roughly 500 meters across. It is powered by a He3 fusion reactor, which can, for all intended purposes, run indefinitely. The Lattice is 40-60 thousand years old (depending on location), with the oldest satellites in the Empire, Utopia and Orion and the most recent ones in the southern part of the Galaxy.

Because the Candles are no more than 60 thousand years old it means that no ship can make a folspace jump longer then 60 thousand light-years because the signal hasn’t had enough time to reach that far. In practical terms a ship will have trouble picking up Locus signals from more than 5-10 thousand light-years no matter how good communication arrays they have.

Problem: Why can’t ships just receive foldcomm transmissions with positional data or use maps???

There are special ships that can fire anti-gravity pulses to pull ships out of foldspace. If the interceptor knows the prey’s entry and exit points as well as exit time, something that’s possible if he has a tracker at the prey’s entry point and the prey is exiting at an inhabited system’s predefined exit marker, then he might wait for the ship several light-days from the exit-marker and fire the anti-gravity pulse at precisely the right moment to pull the ship out. This technique is very new since it only came into being after the anti-gravity experiments of the Special Operations and is highly outlawed since it can cause disruptions to the space-time continuum.