Battlestar Wiki - User contributions [en]

Talk:Navigation in the Re-imagined Series/Archive 1

2007-11-14T17:39:30Z

Ali-Sama: Fixed headers and added comment

== Summery ==
This article comprises the topics on navigation from a past larger article version of [[Science in the Re-imagined Series]], broken out for later expansion and page size considerations. The Reaction Control System article and parts of the FTL article are also included. --[[User:Spencerian|Spencerian]] 08:13, 11 October 2006 (CDT)

== Distances and speeds in the Miniseries ==
There may be a significant error in the section on distances. The 30 minute communications delay between Adar and Roslin is most likely a total round trip delay -- 15 minutes each way, not 30. This would mean that all distances, times, and speeds derived from this number should be halved. --[[User:Girckin|Girckin]] 21:22, 7 November 2006 (CST)
:When Roslin later speaks to 'Jack' over the wireless, there is no such delay whatsoever. Billy may have meant the time it takes to get Roslin's speech from the plane to the President's eyes, or some delay in that process. --[[User:Catrope|Catrope]] 10:07, 2 January 2007 (CST)
:: The use of a real time communication between the two makes the distance much shorter. There is no evidence of ftl communication or sensors in the show. This would make the distance 1/2 a light second to 1 light second at best.--[[User:Ali-Sama|Ali-Sama]] 9:36 am, 14 November 2007 (PST)
== Cleanup ==

I've tagged this for clean-up, it is a mess, for example it has self references, assumptions and original research, which are not encyclopaedic. [[User:MatthewFenton|MatthewFenton]] 15:44, 30 December 2006 (CST)

:Keep in mind, before you make changes, that ''Battlestar Galactica'' is a work of fiction. The information in this encyclopedia is self-referencing sometimes because it is it's own universe. Much of the research involves [[BW:CJ#Derived content|derived content]], which is allowable if it is based on information provided by official information in the show. Be careful not to apply the original research processes os Wikipedia here; they do not fully apply. Please note what items you consider original research so all can review them and determine if the items are derived content or ''unsourced original research'', also known as [[BW:FANW|fanwanking]], which is not allowable here. --[[User:Spencerian|Spencerian]] 23:53, 30 December 2006 (CST)
::"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." - Who is we? Is we me and the wiki, if so how do I know, how does we know? - Basically you should never use the word "we" here -- Self-referencing isn't just writing down text, an example of self-referencing would be an episode page.
:::"Given the velocities involved, extremely high accelerations must be used to attain them in reasonable (useable [''sic'']) 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." - space-folding, when has space-folding been mentioned in the series?
::::Just two things that immediately jump out at me. This page reads like an essay to me at least. [[User:MatthewFenton|MatthewFenton]] 17:34, 1 January 2007 (CST)

:::I agree, Matthew. We can neutralize the writing to make it leas like an essay. If you don't get to it, I'll make the changes. --[[User:Spencerian|Spencerian]] 20:37, 1 January 2007 (CST)

:::: About space-folding: While it hasn't been stated on screen, I recall an interview with Moore and/or Eick, where they said that they wanted to actually show the spacefolding effect in more detail, but couldn't get it to look good. So at the end they settled for the current effect. Or it might even be in "33" or "Miniseries" podcast. --[[User:Serenity|Serenity]] 05:39, 2 January 2007 (CST)

:::::It was from the miniseries DVD commentary, I believe. --[[User:Spencerian|Spencerian]] 07:00, 2 January 2007 (CST)

== 'What happened in "Scattered"' section ==

I've just deleted the entire "What happened in Scattered" section, as it was [[BW:FANW|fanwanking]]. [[User:Whalepelt|Whalepelt]] 20:14, 28 February 2007 (CST)
:I disagree. I think this still falls under derived content. It's more speculative than most articles, but in line with some others, especially in the science section. But it's not made-up outright, nor does it try to explain away inexplicable plotholes (which is what fanwanking is for me). Most it was deduction from a few lines in the episode (like needing to make new starfixes, and the relaying of the jump coordinates), together with some other FTL facts we know, like the need for computations and the concept of a [[blind jump]]. --[[User:Serenity|Serenity]] 08:30, 1 March 2007 (CST)
::I {{support}} the deletion. I'm a big proponent of the science pages (having authored most of them), but as I re-read this section, I realized that there isn't any episode sourcing for the piece, however well-thought out. This section is truly fanwank; to be derived content, it has to know the procedures (not just supposed technical mechanics) of FTL navigation as explained in the show, and that hasn't been detailed in any episode at this time. --[[User:Spencerian|Spencerian]] 10:10, 1 March 2007 (CST)
:::There are snippets of dialogue to back it up. There is the conversation between Saul and Ellen Tigh (referenced in the text), where he explains the basics. And there it's also said that jump plots are continually updated and that Gaeta forgot to send the new ones. So what happened? Something like a blind jump. They had a jump plot, but a wrong one and ended up in a random place unknown to ''Galactica''. We know that such jumps are possible, but they are unpredictable; exactly what happened here. Yeah, it could be sourced better, but the explanation doesn't come out of thin air. The last paragraph is pure speculation and not explained in the episode either, but it's the only possible explanation for what happened. --[[User:Serenity|Serenity]] 10:30, 1 March 2007 (CST)
::::I see your point, although I don't think I can quantify it. Could you readd the relevant parts with supporting sources? --[[User:Spencerian|Spencerian]] 12:45, 1 March 2007 (CST)
:::::Done, and it's better than before. I put the Tigh quote in a footnote, and made a clearer reference to blind jumps. --[[User:Serenity|Serenity]] 13:37, 1 March 2007 (CST)
:::::I'm cool with it. Nice work! --[[User:Spencerian|Spencerian]] 14:02, 1 March 2007 (CST)

== FTL jump calculations ==
*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."

Not true, they can just be [[w:Spherical_coordinate_system|Spherical coordinates]], which draws a line of length r (note the similar notation to radius), but with a specific orientation in space depending the angles θ and φ. No special space-folding math here.--[[User:DuMan|DuMan]] 16:28, 30 June 2007 (CDT)
:Mhh, true. Guess we can just change this to general coordinates, and say that they could be either cartesian or spherical. --[[User:Serenity|Serenity]] 16:41, 30 June 2007 (CDT)

== No credit! ==

I went to ''all that trouble'' of witing about and calculating the time dilation, an addition that I originally made at [[Science in the Re-imagined Series]] over a year ago, but now I find it on this page, and I am not in either page's edit history! What's up with that? I thought this was cc-''by''-sa. Where is my frakkin' credit?!! --[[User:Bp|Bp]] 05:26, 26 August 2007 (CDT)

:Oh, I guess I am still in the edit history at [[Science in the Re-imagined Series]]. I missed it. Anyway, wasn't really mad about it; just was looking for the time dilation info and couldn't find it on that page. --[[User:Bp|Bp]] 05:30, 26 August 2007 (CDT)

::Your contributions were probably moved over to this article when the original science article was split over several pages because it became too long and about too many topics (at least I think that's what happened). But technically we don't have page ownership here ;( --[[User:Serenity|Serenity]] 05:38, 26 August 2007 (CDT)
::Right, no page ownership, but attribution is required by the license. An editor's work is released to BSG wiki under the cc license, and BSG wiki releases it to others in the same way. But it doesn't matter, I was just making a big deal about it because I couldn't find the text when I wanted to. --[[User:Bp|Bp]] 07:03, 26 August 2007 (CDT)

== Triangulation ==

You say, "To calculate the approximate 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 labeled 'Earth' and the point labeled 'Lagoon Nebula.'" Well, that would be 4,100 light-years. You meant 'Colonies' and 'Lagoon Nebula' or 'Colonies' and 'Earth'. However, these distances are unknown, and so I don't see where the 10,250 light year estimate came from. --[[User:MHall|MHall]] 01:43, 13 October 2007 (CDT)

== RCS ==

In Roslin's press conference in The Hand of God, Playa Palacios states that the fleet would be unable to perform basic combat manouveres without fuel. Since reaction control thrusters are used for ships to manouvere, and she is obviously referring to tylium by "fuel" (because tylium is the only thing the fleet salvages from the asteroid), does this mean that we can add that Colonial RCS systems are also fueled by refined tylium?--[[User:Rapturous|Rapturous]] 18:14, 21 October 2007 (CDT)

== Lion's Head Nebula / Constellation Leo ==

Inasmuch as the Fleet passes through the [[Lion's Head Nebula]] on the path toward [[Earth]], I note that a straight line drawn from the [[Wikipedia:Lagoon Nebula|Lagoon Nebula]] through the [[Wikipedia:Sol System|Sol System]] and continuing out toward the Galactic Edge passes through the constellation [[Wikipedia:Leo_%28constellation%29|Leo, the Lion]], which includes the intensely bright blue-white star [[Wikipedia:Regulus|Regulus {Alpha Leonis, "the Lion's Heart")]]. Does anyone know if this was intentional or is it an ironic coincidence? -- [[User:Davidkevin|Davidkevin]] 07:58, 5 November 2007 (CST)
:Mhhh, interesting. I think it's a coincidence, since - unlike the lagoon nebula - the lion's head nebula is fiction. Might be worth adding as a note to the nebula article though. --[[User:Serenity|Serenity]] 14:51, 5 November 2007 (CST)

Navigation in the Re-imagined Series

2007-11-14T16:47:22Z

Ali-Sama: Alternate calculations for distances and speeds in the Miniseries

{{RDM science series}}
In the Re-imagined Series, the principles of spaceflight are taken seriously, in that all ships have a logical a process to move in all three axes of movement, and travel at reasonable speeds with 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 [[Propulsion in the Re-imagined Series#Sublight propulsion|sublight engines]] used for interplanetary travel within a solar system, all ships 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, a reaction control system<ref>In the movie, ''Apollo 13'', the Apollo command/service module's reaction control jets are violently activating to control the spacecraft after the famous oxygen tank explosion, which creates an uncontrolled jet for which the RCS tries to compensate.</ref>.

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
* Station keeping 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.

* [[Viper (RDM)|Vipers]], [[Raptor]]s and all smaller craft use "cold" RCS systems, most likely utilizing either an inert gas or possibly a high specific-impulse [[Wikipedia:Hypergolic fuel|hypergolic fuel]] mixture
* Very large vessels such as [[battlestar]]s use strategically-mounted sets of very large fuel-burning thrusters, relying on the brute force of such systems to overcome inertia during maneuvers.

Like many other technologies, Cylon attitude control for small craft like [[Cylon Raider (RDM)|Raiders]] is similar or even identical to the Colonials ([[Scar]]).

[[Basestar (RDM)|Basestars]] don't appear to have ''any'' RCS features. This may be an inherent design, as its Raiders and 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.

While basestars have no visible RCS, orientation can be achieved through other means. For examples, reaction wheels use a spinning mass on a spacecraft axis to control attitude. By spinning the reaction wheel in one direction, torque is generated and the spacecraft will rotate in the opposite direction, in accordance with Newton's laws of motion. This system is used on real space platforms, such as the Hubble Space Telescope. However, such systems generate relatively small amounts of torque and they tend to be used in situations where precise orientation takes priority over the need to change orientation rapidly.

Basestars however, have a sublight propulsion system in addition to FTL drives. Basestars can be seen approaching the [[algae planet]] in the episode "[[The Eye of Jupiter]]". This capability can also be inferred from episodes like "[[The Captain's Hand]]" where a basestar is said to be retreating. Its nature however is unknown, as like with the RCS system, no engines are visible on the vessels.

==Distances and speeds in the Miniseries==

* '''''Galactica'' was approximately 335,540,340 miles from one of the Colonies, ostensibly [[The Twelve Colonies (RDM)#Caprica|Caprica]], at the start of the [[Miniseries]].'''

To reach this number, clues are taken from [[Billy Keikeya]], on ''[[Colonial Heavy 798]]'', enroute to the battlestar for its decommissioning ceremony. Keikeya tells [[Laura Roslin]] that he had sent a copy of her ceremony speech to President [[Richard Adar|Adar]] for review, but warns that there is a time delay of 30 minutes between ''Galactica'' and Adar's actual location, which is [[Epiphanies|confirmed]] as Caprica City, the seat of the Colonial [[Government]] <ref name="jack">President Adar's office on Caprica is confirmed in the second Season episode, "[[Epiphanies]]". Reinforcing this information, Roslin speaks by [[wireless]] to "[[Jack]]", a fellow secretary or government official. Jack tells Roslin of the devastation near his location and Adar's speculated whereabouts and actions. Given that wireless transmission ranges in real-time conversation would limit Roslin to be able to speak only with Caprica (the nearest colony), Jack must be on Caprica, and likely in Caprica City to give him any ability to discuss the president's whereabouts.</ref>.

The speed of light (and of wireless transmissions) in vacuum is 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 makes it possible to determine the distance using the equation: ''s = vt'' (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'''

Simplified, the wireless message travels over 335.5 million miles in 30 minutes to ''Galactica''. This is approximately 3.5 [[w:Astronomical unit|astronomical units]], or 3.5 times the distance between Earth and our sun.

* '''''Colonial Heavy 798'' is traveling 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 with Laura Roslin on her speech, the captain of ''Colonial Heavy 798'' speaks on the public address intercom of the [[Intersun|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 moving very fast 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 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 (usable) 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"<ref>This nature of the jump technology is confirmed in the Miniseries podcast</ref> 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 [[Wikipedia:Time dilation|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.

==Alternate calculations for distances and speeds in the Miniseries==

This is an alternative to the above which assumes a thirty light minute distance.
A time lag <ref>{{cite_web|url=http://en.wikipedia.org/wiki/Lag|title =Tim lag/Latency defintion on wikipedia}}</ref> or delay or Latency, in the case of a communication signal is both ways. A thirty minute time lag in
communication implies that the signal would take fifteen minutes to travel between the two creating a total lag of thirty minutes. In short: It takes thirty minutes for person one to send a message and get a reply
back. This would alter the calculations made to the following.

-''Galactica's'' distance from Caprica would be: 167,500,000 miles

(3 x 10^8 m/s) (the speed of light) x 1800 s (15 minutes * 60 seconds/minute) = 2.7 x 10^11 meters or 167,500,000 miles

-The speed of ''Colonial Heavy 798'' would be 305057.07 mph

2.7x 10^11 meters (the distance in meters) / 19800 (5.5 hours x 3600 seconds/hour) =
13,636,363.64 meters/sec, or 305057.07 mph

-This makes the same assumptions as to the route of ''Colonial Heavy 798'' as the initial proposal.

==FTL jump calculations==

Based on deduction from information gleaned in "[[Scattered]]", a set of jump coordinates could either be given in [[w:Cartesian coordinate system|cartesian]] or [[w:Spherical coordinate system|spherical]] coordinates to specify a point in three-dimensional space.

A possible algorithm for jump calculations would therefore necessitate first and foremost the determination 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 <ref name="tighquote"/>. Next, the ship's position relative to the intended point of arrival would be [[w:Point plotting|plotted]] on a three-dimensional coordinate system, using the ship as its [[w:Origin (mathematics)|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 Anchorage|Ragnar]] in the Miniseries, would therefore lie not so much in getting the jump drive to manipulate space properly, as in correctly figuring out where possible obstacles, such as stars, black hole or planetary bodies are located and then adjusting the direction of the jump accordingly, so as to land the ship in a clear volume of space.

== Astrometrics ==

{{mainarticle|Astrometrics}}

''Galactica'' has an astrometrics lab with optical and x-ray telescopes, that is used to acquire fixes on surrounding stars, which are then used in FTL jump calculations.

==Triangulating the Colonies' "Actual Location" ==

[[Image:Lagoonnebula.jpg|thumb|right|150px|Lagoon Nebula]]
In "[[Home, Part II]]", the [[Wikipedia:Lagoon Nebula|Lagoon Nebula]] appears in a holographic map in the constellation of Scorpio<ref>In the show, the nebula is placed in the wrong constellation. On Earth, the nebula actually appears in the constellation Sagittarius. The production team has acknowledged this as an error.</ref> in the [[Tomb of Athena]].

''Galactica's'' location and the rough location of the Twelve Colonies of Kobol can be deduced with simple logic:
[[Image:Locations in BSG galaxy.jpg|thumb|left|150px|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.

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 [[Wikipedia:Cygnus Arm|Cygnus Arm]] of the Milky Way galaxy.

To calculate the approximate 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 labeled 'Earth' and the point labeled 'Lagoon Nebula.' Then, one must use this scale and measure the distance between the Colonies and Earth. Then convert it to light years. The approximate distance using this method is 10,250 light-years.
<div style="clear: both;"></div>

==What happened in "Scattered"?==

[[Image:jump calculations.jpg|thumb|left|Schematic Diagram showing the three different sets of jump coordinates]]
In "[[Scattered]]", [[Galactica (RDM)|''Galactica'']] and the [[The Fleet (RDM)|Fleet]] execute FTL jumps according to different sets of coordinates. As a consequence, ''Galactica'' has to jump back along its original jump vector, to the former point of origin of the two jumps, re-acquire new starfixes and calculate the Fleet's current position.

At first glance, this seems counter-intuitive. Since presumably both sets of jump coordinates are known to ''Galactica'', a simple triangulation of the two jump vectors would produce an alternative third set of jump-coordinates which would allow ''Galactica'' to jump to the Fleet directly. A possible explanation is as follows:

The [[emergency jump coordinates]] given to the civilian fleet aren't just an older set of correct coordinates. According to Colonel Tigh, in a conversation with his wife, jump calculations need to be regularly updated to compensate for stellar drift and the movement of the ships themselves. Lieutenant Gaeta was supposed to send the updated jump plots to the other ships but forgot to. <ref name="tighquote">Tigh: "Every watch we update our emergency jump calculations with new star fixes to compensate for inertial drift, and then we transmit them to the rest of the Fleet. This time ours were updated, but theirs weren't. Gaeta was supposed to transmit them to the rest of the Fleet." ([[Scattered]])</ref> As a result, the Fleet jumped with a set of coordinates that didn't fit the local space-time conditions. The concept of a [[blind jump]] is introduced in the episode "[[Pegasus (episode)|Pegasus]]". While jumping with a wrong sets of coordinates probably isn't as risky as jumping with no calculations at all, the destination would still be unpredictable.

''Galactica'' has the coordinates that the civilian ships used to make their jumps, but not their actual position. However, in a process that is largely unexplained, ''Galactica'' is then able to calculate their real location from the Fleet's emergency jump coordinates, as well as the newly acquired starfixes. This unusual procedure can also explain the abnormally long duration (several hours) of the calculations on the initially un-networked computers, compared to the relatively short amount of time jump calculations usually take.

==References==
<div style="font-size:85%"><references/></div>

[[Category:A to Z]]
[[Category:RDM]]
[[Category:Technology]]
[[Category:Technology (RDM)]]
[[Category:Terminology]]
[[Category:Terminology (RDM)]]

Navigation in the Re-imagined Series

2007-01-16T04:43:39Z

Ali-Sama: /* Alternate calculations for distances and speeds in the Miniseries */

{{cleanup}}
{{RDM science 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 [[Propulsion in the Re-imagined Series#Sublight propulsion|sublight engines]] used for interplanetary travel within a solar system, all ships (except, perhaps, for [[Basestar (RDM)|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<ref>In the movie, ''Apollo 13'', you can see the Apollo command/service module's reaction control jets violently activating to control the spacecraft after the famous oxygen tank explosion, which creates an uncontrolled jet for which the RCS tries to compensate.</ref>.

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 Fleet (RDM)|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 [[Wikipedia:Hypergolic fuel|hypergolic fuel]] mixture
* Very large vessels such as [[battlestar]]s use strategically-mounted sets of very large fuel-burning thrusters, relying on the brute force of such systems to overcome inertia during maneuvers.

[[Cylons (RDM)|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.

[[Basestar (RDM)|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 [[The Twelve Colonies (RDM)#Caprica|Caprica]], at the start of the [[Miniseries]].'''''

To reach this number, we needed clues from [[Billy Keikeya]], on ''[[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 [[Richard Adar|Adar]] for review, but warns that there is a time delay of 30 minutes between ''Galactica'' and Adar's actual location, which is [[Epiphanies|confirmed]] as Caprica City, the apparent seat of the Colonial [[Government]] <ref name="jack">President Adar's office on Caprica was confirmed in the second-season episode, "[[Epiphanies]]." Reinforcing this information, Roslin speaks by [[wireless]] to "[[Jack]]", a fellow secretary or government official. Jack tells Roslin of the devastation near his location and Adar's speculated whereabouts and actions. Given that wireless transmission ranges in real-time conversation would limit Roslin to be able to speak only with Caprica (the nearest colony), Jack must be on Caprica, and likely in Caprica City to give him any ability to discuss the president's whereabouts.</ref>.

The ''Battlestar Galactica'' 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, the captain of ''Colonial Heavy 798'' speaks on the public address intercom of the [[Intersun|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 (usable) 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 [[Wikipedia:Time dilation|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''.

==Alternate calculations for distances and speeds in the Miniseries==

This is an alternative to the above which assumes a thirty light minute distance.
A time lag <ref>{{cite_web|url=http://en.wikipedia.org/wiki/Lag_time|title =time lag defintion on wikipedia}}</ref> or delay , in the case of a communication signal is both ways. A thirty minute time lag in
communication implies that the signal would take fifteen minutes to travel between the two creating a total lag of thirty minutes. In short: It takes thirty minutes for person one to send a message and get a reply
back. This would alter the calculations made to the following.

-''Galactica's'' distance from Caprica would be: 167,500,000 miles

(3 x 10^8 m/s) (the speed of light) x 1800 s (15 minutes * 60 seconds/minute) = 2.7 x 10^11 meters or 167,500,000 miles

-The speed of ''Colonial Heavy 798'' would be 305057.07 mph

2.7x 10^11 meters (the distance in meters) / 19800 (5.5 hours x 3600 seconds/hour) =
13,636,363.64 meters/sec, or 305057.07 mph

-This makes the same asumptions as to the route of ''Colonial Heavy 798'' as the initial proposal.

==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. <ref name="tigh">This much is explained by Col. Tigh to his wife Ellen in "Scattered".</ref>

Next, the ship's position relative to the intended point of arrival would be [[Wikipedia:Point plotting|plotted]] on a three-dimensional [[Wikipedia:Cartesian coordinate system|Cartesian coordinate system]], using the ship as its [[Wikipedia:Origin (mathematics)|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 Anchorage|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"?===
[[Image:jump calculations.jpg|thumb|left|Schematic Diagram showing the three different sets of Jump Coordinates]]
In "[[Scattered]]", [[Galactica (RDM)|''Galactica'']] and the [[The Fleet (RDM)|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 [[Wikipedia:General Relativity|"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 [[Wikipedia:Sun|Suns]] and [[Wikipedia:Black holes|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" ==
[[Image:Lagoonnebula.jpg|thumb|right|150px|Lagoon Nebula]]
In "[[Home, Part II]]," the [[Wikipedia:Lagoon Nebula|Lagoon Nebula]] appears in a holographic map in the constellation of Scorpio<ref>In the show, the nebula is placed in the wrong constellation. On Earth, the nebula actually appears in the constellation Sagittarius. The production team has acknowledged this as an error.</ref> 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.
[[Image:Locations in BSG galaxy.jpg|thumb|left|150px|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 [[Wikipedia:Cygnus Arm|Cygnus Arm]] of the Milky Way galaxy.

To calculate the approximate 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 approximate distance using this method is 10,250 light-years.
<div style="clear: both;"></div>

==References==
<div style="font-size:85%"><references/></div>

[[Category:A to Z]]
[[Category:RDM]]
[[Category:Technology]]
[[Category:Technology (RDM)]]
[[Category:Terminology]]
[[Category:Terminology (RDM)]]

Navigation in the Re-imagined Series

2007-01-10T22:04:29Z

Ali-Sama:

{{cleanup}}
{{RDM science 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 [[Propulsion in the Re-imagined Series#Sublight propulsion|sublight engines]] used for interplanetary travel within a solar system, all ships (except, perhaps, for [[Basestar (RDM)|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<ref>In the movie, ''Apollo 13'', you can see the Apollo command/service module's reaction control jets violently activating to control the spacecraft after the famous oxygen tank explosion, which creates an uncontrolled jet for which the RCS tries to compensate.</ref>.

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 Fleet (RDM)|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 [[Wikipedia:Hypergolic fuel|hypergolic fuel]] mixture
* Very large vessels such as [[battlestar]]s use strategically-mounted sets of very large fuel-burning thrusters, relying on the brute force of such systems to overcome inertia during maneuvers.

[[Cylons (RDM)|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.

[[Basestar (RDM)|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 [[The Twelve Colonies (RDM)#Caprica|Caprica]], at the start of the [[Miniseries]].'''''

To reach this number, we needed clues from [[Billy Keikeya]], on ''[[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 [[Richard Adar|Adar]] for review, but warns that there is a time delay of 30 minutes between ''Galactica'' and Adar's actual location, which is [[Epiphanies|confirmed]] as Caprica City, the apparent seat of the Colonial [[Government]] <ref name="jack">President Adar's office on Caprica was confirmed in the second-season episode, "[[Epiphanies]]." Reinforcing this information, Roslin speaks by [[wireless]] to "[[Jack]]", a fellow secretary or government official. Jack tells Roslin of the devastation near his location and Adar's speculated whereabouts and actions. Given that wireless transmission ranges in real-time conversation would limit Roslin to be able to speak only with Caprica (the nearest colony), Jack must be on Caprica, and likely in Caprica City to give him any ability to discuss the president's whereabouts.</ref>.

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 [[Intersun|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 (usable) 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 [[Wikipedia:Time dilation|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''.

==Alternate calculations for Distances and speeds in the Miniseries==

This is an alternative to the above which assumes a thirty light minute distance.
A time lag <ref>{{cite_web|url=http://en.wikipedia.org/wiki/Lag_time|title =time lag defintion on wikipedia}}</ref> or delay , in the case of a communication signal is both ways. A thirty minute time lag in communication implies that the signal would take fifteen minutes to travel between the two creating a total lag of thirty minutes total. In short: It takes thirty minutes for person one to send a message and get a reply back. This would alter the calculations made to the following.

The distance of the Calactica from Caprica would be: 167,500,000 miles

(3 x 10^8 m/s) (the speed of light) x 1800 s (15 minutes * 60 seconds/minute) = 2.7 x 10^11 meters or 167,500,000 miles

the speed of colonial heavy 798 would be 305057.07 MPH

2.7x 10^11 meters (the distance in meters) / 19800 (5.5 hours x 3600 seconds/hour) =
13,636,363.64 meters/sec, or 305057.07 MPH

==FTL jump calculations==
Based on deduction from information gleaned in "[[Scattered]]", a set of jump Coordinates used to execute an FTL jump "tells" the Jjmp 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. <ref name="tigh">This much is explained by Col. Tigh to his wife Ellen in "Scattered".</ref>

Next, the ship's position relative to the intended point of arrival would be [[Wikipedia:Point plotting|plotted]] on a three-dimensional [[Wikipedia:Cartesian coordinate system|Cartesian coordinate system]], using the ship as its [[Wikipedia:Origin (mathematics)|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 Anchorage|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"?===
[[Image:jump calculations.jpg|thumb|left|Schematic Diagram showing the three different sets of Jump Coordinates]]
In "[[Scattered]]", [[Galactica (RDM)|''Galactica'']] and the [[The Fleet (RDM)|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 [[Wikipedia:General Relativity|"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 [[Wikipedia:Sun|Suns]] and [[Wikipedia:Black holes|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" ==
[[Image:Lagoonnebula.jpg|thumb|right|150px|Lagoon Nebula]]
In "[[Home, Part II]]," the [[Wikipedia:Lagoon Nebula|Lagoon Nebula]] appears in a holographic map in the constellation of Scorpio<ref>In the show, the nebula is placed in the wrong constellation. On Earth, the nebula actually appears in the constellation Sagittarius. The production team has acknowledged this as an error.</ref> 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.
[[Image:Locations in BSG galaxy.jpg|thumb|left|150px|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 [[Wikipedia:Cygnus Arm|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.
<div style="clear: both;"></div>

==References==
<div style="font-size:85%"><references/></div>

[[Category:A to Z]]
[[Category:RDM]]
[[Category:Technology]]
[[Category:Technology (RDM)]]
[[Category:Terminology]]
[[Category:Terminology (RDM)]]