Navigation in the Re-imagined Series

An article from Science in the Re-imagined Series

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Travelling between your homeworlds is one matter. Travelling through the galaxy with a motley assortment of ships to a place of legend in an unexplored region of space makes plotting a course difficult at best.

This article discusses the issues involving navigating about in the universe of the Re-imagined Series.

In the Re-imagined Series, the principles of flight are taken with greater seriousness in that all ships have as logical a process to move in all through axes of movement, and at reasonable speeds and methods that don't necessarily duplicate the fantasy flight principles seen in space fantasy, such as Star Wars.

Reaction Control Systems

In addition to their sublight engines used for interplanetary travel within a solar system, all ships (except, perhaps, for basestars) have a centralized way to move the ship to port or starboard, and to yaw and rotate the ship. This requires the use of an RCS, or a reaction control system.

The reaction control system is designed to provide a spacecraft with guidance and steering. It has two main functions:

• Delivering small amounts of thrust in any desired direction or combination of directions
• Providing torque to allow control of rotation (pitch, yaw, and roll).

Reaction control systems are typically used for:

• Attitude control during entry into an atmosphere until such time as conventional aerodynamic surfaces can be used
• Stationkeeping in orbit
• Close maneuvering and/or docking
• Orientation control (pointing the nose of the vehicle).

All Colonial vessels utilize RCS for maneuvering and station keeping, although the scale of the systems varies widely.

• Vipers, Raptors and all smaller craft appear to use "cold" RCS systems, most likely utilizing either an inert gas or possibly a high specific-impulse hypergolic fuel mixture
• Very large vessels such as battlestars use strategically-mounted sets of very large fuel-burning thrusters, relying on the brute force of such systems to overcome inertia during maneuvers.

Cylon manuevering technology for their small craft use RCS systems that are similar in form and function to Colonial systems. The episode "Scar" clearly depicts a Cylon Raider using RCS jets for attitude control.

Basestars don't appear to have any RCS features. In fact, it is unknown if a basestar has any kind of propulsion other than its FTL drive. This appears to be an inherent design, as Raiders and its missile systems can be deployed in a 360-degree arc--that is, the basestar can deploy its offensive elements from any direction of the ship.

Distances and Speeds in the Miniseries

• Battlestar Galactica was approximately 335,540,340 miles from one of the Colonies, ostensibly Caprica, at the start of the Miniseries.

To reach this number, we needed clues from Billy Keikeya, onboard Colonial Heavy 798, enroute to the battlestar for its decommissioning ceremony. In the Miniseries, Keikeya tells Laura Roslin that he had sent a copy of her ceremony speech to President Adar for review, but warns that there is a time delay of 30 minutes between Galactica and Adar's actual location, which is confirmed as Caprica City, the apparent seat of the Colonial Government .

We know that Battlestar Galactica's universe sticks to the same speed of light constant as real-world Earth (and the universe, of course): 186,282 miles per second. If President Adar sent a wireless message from Caprica to Galactica in an attempt to correct Roslin's speech, how long would it take the message to get there? Keikeya gives this answer: 30 minutes. This allows us to determine the complete answer we need if we use the equation: d = s(t) (or, distance=speed x time)

(3 x 10^8 m/s) (the speed of light) x 1800 s (30 minutes * 60 seconds/minute) = 5.4 x 10^11 meters or 335, 500, 000 miles

Simplfied, the wireless message travels over 335.5 million miles in 30 minutes to Galactica. This is approximately 3.5 astronomical units, or three times the distance between our Earth and our sun.

• Colonial Heavy 798 is travelling at a sublight speed of over 61,000,000 miles per hour to get to Galactica for the decommissioning ceremony.

Right after Billy Keikeya's conversation to Laura Roslin on her speech, we overhear the captain of Colonial Heavy 798 on the public address intercom of the starliner, telling the passengers how long their trip to Galactica will take: 5.5 hours. Assuming that the starliner has just left the neighboring space of Caprica and has reached its cruising speed, and given that we know Galactica's distance from Caprica, we can determine Colonial Heavy 798's cruising speed with the same formula as above, now adjusted to calculate speed:

5.4 x 10^11 meters (the distance in meters) / 19800 (5.5 hours x 3600 seconds/hour) =

2.7 x 10^7 meters/sec, or 61, 000, 000 MPH

While Colonial Heavy 798 is making a very serious clip across space at 61, 000, 000 miles per hour on its sublight engines, this is only approximately 11 percent of the speed of light, so passenger liners do well in getting from place to place, or colony to colony. To give a real-world comparison, Colonial Heavy 798 could fly from our sun to the Earth in about 90 minutes. The light from the sun takes only 8 minutes to arrive on the Earth's surface.

Given the velocities involved, extremely high accelerations must be used to attain them in reasonable (useable) time frames involved for in-system transportation. Such G forces would kill any humans involved unless some means of dampening them were employed. Given that the technology to perform "space-folding" FTL Jumps is also available, the technology to manipulate gravity would lie in the same area.

• Colonial Heavy 798 and it's passengers would lose about 1 minute and 19 seconds during their trip to Caprica (relative to the time observed on Caprica), if they had completed their trip as planned, due to time dilation.

T = T0 / sqrt(1 - v^2/c^2)

• T0 = 5.5 hours. (as observed by Colonial Heavy 798)
• d = 335,540,340 miles.
• v = d/T (as observed by Caprica)
• c = 670,616,624.4 mph
• T = 5.52 hours. (1:19 longer observed on Caprica)

Of course, this assumes that Colonial Heavy 798 took the same path to Caprica that its transmission would take. This isn't likely, for various reasons, so the distance is probably off a little.

FTL Jump Calculations

Based on deduction from information gleaned in Scattered, a set of Jump Coordinates used to execute an FTL Jump "tells" the Jump drive to fold space along a vector of three dimensions:

• Elevation
• Rotation
• Distance

Here, the dimension of distance would represent more than just a straight line, plotted through three-dimensional space but the amount of space curvature that the jump drive would have to fold.

A possible algorithm for jump calculations would therefore necessitate first and foremost the figuring out of the exact location of the ship, relative to its intended point of arrival after the jump. This is done by identifying, fixing and triangulating several stars.

Next, the ship's position relative to the intended point of arrival would be plotted on a three-dimensional Cartesian coordinate system, using the ship as its point of origin, i.e. (0/0/0).

Then, the positions of any known stellar bodies and other obstacles would have to be plotted on that coordinate system as well, in order to establish where to jump and where not to jump.

Finally, the point of arrival would likewise be plotted. The hard part in making a single jump over long distances, like to Ragnar in the Miniseries, would therefore lie not so much in getting the jump drive to fold space correctly, as in correctly figuring out where possible obstacles, such as a sun or a black hole, are located and then adjusting the direction of the jump accordingly, so as to land the ship in a clear volume of space.

What happened in "Scattered"?

Schematic Diagram showing the three different sets of Jump Coordinates

In "Scattered", Galactica and the Fleet executed jumps according to different sets of coordinates. As a consequence, Galactica had to jump back along its original jump vector, to the former point of origin of the two jumps, reacquire the former starfixes and calculate a best-fit solution given the Fleet's current position.

At first glance, this seems counter-intuitive. Since presumably both sets of jump coordinates were known to Galactica, a simple triangulation of the two jump vectors would have produced an alternative third set of jump-coordinates which should have allowed Galactica to jump to the Fleet directly. A possible explanation for the complications that arise in such a case may lie in the "Curvature" of space and the fact that ships retain their initial velocity through a jump. This can be seen in the Miniseries immediately after Galactica jumps to Ragnar. The battlestar leaves the Jump, still moving at its sublight velocity before the Jump occurred.

Space is not flat, but distorted by stellar masses, especially Suns and Black Holes. Assuming that FTL Jumps cover enormous distances, the two different jumps would place lots of unknown stellar bodies between Galactica and the Fleet, distorting space and thereby screwing up the dimension of "Distance" in the above mentioned third set of jump-coordinates.

Furthermore, the Emergency Jump Coordinates given to the civilian fleet weren't just an older set of correct coordinates. According to Colonel Tigh jump calculations need to be regularly updated to compensate for stellar drift and the movement of the ships themselves. The fleet jumped with a set of coordinates that didn't fit the local space-time conditions. That might have placed them in an unknown location. It's possible that Galactica was able to calculate their real location from the fleet's Emergency Jump Coordinates as well as the newly acquired starfixes. This unusual procedure could also explain the abnormally long duration (several hours) of the calculations on the initially unnetworked computers.

Triangulating the Colonies' "Actual Location"

Lagoon Nebula

In "Home, Part II," the Lagoon Nebula appears in a holographic map in the constellation of Scorpio in the Tomb of Athena.

Some fans have deduced Galactica's location and the rough location of the Twelve Colonies of Kobol from the aired data with simple but brilliant logic.

Possible locations

The nebula is shown from the same vantage point as it would appear to an observer on Earth, yet the characters are able to recognize it. This suggests that the Colonies are on a line of sight "behind" Earth's Solar System. Otherwise, the nebula would appear in a different shape and size as it is not a symmetrical object. The effect is similar to two people, both facing the same direction and standing in a row, looking at the face of a person standing in front of them.

If one were to follow a straight line from the Lagoon Nebula to Earth, continuing the line through space would place Galactica, and likely the Colonies, somewhere in the Cygnus Arm of the Milky Way galaxy.

To calculate the apox distance between the Colonies and Earth, using the map to the left, one must first get the distance between the Lagoon Nebula and Earth, 4,100 light-years. One must then determine the distance between the point labled 'Earth' and the point labled 'Lagoon Nebula.' Then, one must use this scale and measure the distance between the Colonies and Earth. Then convert it to light years. The aprox distance using this method is 10,250 light-years.

Re-imagined Series definition: technology enabling travel across distances faster than the speed of light would permit, see: FTL

Re-imagined Series definition: Colonial equivalent of radio

Re-imagined Series definition: used to signify a civilian transport vessel over a certain gross weight/mass, i.e. Colonial Heavy 798

Re-imagined Series definition: the process of using the FTL engines to make an near-instantaneous apparent faster-than-light transport of a ship from one point in space to another

Re-imagined Series definition: callsign used in wireless communications to denote a ship's commanding officer