Finding some real facts on the actual Battlestars themselves is very difficult. Most information out there is fan based, but real data is very difficult to find. However there are some facts that need answering, so here is where I present my views. I am not claiming these are correct (they certainly are not official), but they are my views and my site and stats are based on this perception.
For the record though, while I may be wrong about absolutely everything here (from size to amount of Vipers) - and if I get the proof I will be the first to admit that I am wrong - the thing I am positive about, is that the Galactica Does Not have missiles. I am almost willing to bet my life on that, and it will take an awful lot to convince me otherwise!
And yes, you can take that as a challenge!
We do not know. Simple as that.
Well, there are several figures going around at the moment. The most common is one that appears in unofficial but recognised works (like the Encyclopedia Galactica, the 1979 Battlestar Galactica Annual and a few more) that states the length is 2,000 feet.
Then we get some views from the model makers themselves that state:
"There was never an exact length quoted for the Galactica on screen, in Colonial _or_ Earth units. Various fan and modelling publications have quoted lengths of 2,000 feet or "one mile", but these have no firm basis in the series. Recently, forgotten his name, one of the three men who own the Galactica Archives, a collection of BG props, costumes and related material, wrote in a British modelling magazine that he estimated the scale of the original 76-inch Galactica miniature to be around 1/960, based on the size of the landing bay entrance. This would make the full-size ship 6,080 feet (1,853 metres) long -- by coincidence, exactly (pre-SI) one nautical mile. This is as definitive a value as we are likely to get, barring pronouncements from Glen Larson."
Source was from Robert Hanczyk's fan fiction and picture site which appears to have become lost in the void.
Then we have other sites (fandom) sites saying anything from 1 kilometre to 14!
And finally we have blurb from the books and the 1979 Offical Film Brochure which states that it is "The Battlestar Galactica, a space ship more than a mile long, with a cruising speed measured in light seconds, skims through a distant starfield." and then lists a quote from Glen Larson saying "As for the Galactica itself, Larson conceived it as a city in space, ten times larger than the largest aircraft carrier known today, armed with weapons which have not - and will not be - invented for thousands of years."
So which is right and why?
I do not know at all. There are sites which try to who the length of Battlestar as 2,000 feet by showing pixel diagrams with Vipers to scale (the NewsFlash Galactica site was a prime example of this), but there are other sites which use the same method to prove otherwise (the Battlespoo Site by Todd Boyce is an excellent site for the whole size debate). Unlike the other things listed here, there just is not any information at all to prove or disprove otherwise.
I like the size of a nautical mile best (and indeed the SSD's where original written with that in mind) but I am going to stick with the 1,265 metres size that fandom currently think.
However just because it is semi-offical does not mean that it is right, as the next question will prove!
It is interesting to note that the original novelisations, while not giving any actual details, do describe the Galactica a vast ship, with a crew of thousands. Again, while they do not give real details, they do make the ship out to be much larger than 2,000 feet!
Current fandom is stating that the Galactica is around 1,265 metres in length, which is nice figure I feel.
We know that Battlestars carry two squadrons of fighters (I think we can assume one per landing bay, but it is probably not that simple!), however the only actual figure we get is during the episode "Hand of God" where Colonel Tigh during his briefing, explains that Cylon Baseships carry some three hundred Raiders, and that the Colonials will be outnumbered two to one. This suggests that the Battlestars carry come 150 fighters, but does it take into account the fact that at that point the Galactica was carrying some four squadrons (the additional two from the Pegasus) and battle damage?
If it takes into account the additional squadrons, then the Battlestars only carry some 75 fighters each. Does it also take into account Vipers from other Battlestars? In the very first episode "Saga of a Star World" we learn that only 69 Vipers survived the ambush (which is interesting in itself - apparently some 20 odd Vipers were from the Galactica, so this means that the others were from the other four Battlestars present, yet it is clearly stated that no other Battlestar was able to launch fighters... Go figure that one! So, this is proof that some Colonials were elsewhere at the time of the Peace Conferance at least.).
But then we do not know how many fighters were elsewhere at the time of the ambush and managed to come back to go with the Galactica.
This is then 'confused' by the "The Living Legend, part II" where it is stated that the Vipers being used to spearhead the Pegasus's attack on the Baseships would be outnumbered 3 to 1. The attacking forces come from three Baseships. Now, later on Apollo mentions that both colonial squadrons were on the Pegasus, so if we then use this with the information above, we get about 300 Vipers vs around 900 Raiders (ouch!). It does make it tally that the fighter complements of two Battlestars equal about one Baseship, so it does suggest that a Battlestar carries around 150 Vipers, but it then also leads one to wonder just where the rest of the Vipers went when the episode "Hand of God" came along... How do you lose 150 Vipers? But, it would answer the following paragraph very nicely with the simple answer of 'they have not and can not'.
So what about battle damage? In most episodes we see Vipers being destroyed (just how many were wasted at the Battle of Gomoray in "The Living Legend"?), and never do we find out if the fleet had the ability to build new ships.
So if we assume that it does take into account losses, then that still makes a lot of Vipers.
Just been watching "The Hand of God" again, and this time I am sure that the producers have either forgotten that the Galactica now contains the two Pegasus squadrons, or else we have to assume that the Galactica has lost an awful lot of fighters. The reasoning behind this one is that when the Cylons detect the vipers, the Gold Cylon states questionably "Vipers?" and the response is "Confirmed, two squadrons". Which means that the Galactica has two squadrons of 75 Vipers. Now, this is not supposed to be proof that a Battlestar contains 150 Vipers, just that she had them at that point. Which certainly contradicts the above. I am actually believing that the producers forgot about the two additional squadrons, and therefore I think that a Battlestar does contain 150 Vipers, or there abouts - the last reference to Slverspar squadron that I can find is in "War of the Gods, part 1" when it is mentioned that only Blue squadron is left out of Red, Blue and Silverspar.
This can complicate things horrendously and turn a relatively simple question into a very difficult one to answer due to the amount of variables that are present.
(or does the Galactica have missiles?)
Very interesting question this one. In all the literature that I have seen (except the two novels) and all the fan sites, it states that all Battlestars have missiles. While I agree that the Pegasus has missiles (we see them after all!), and therefore I agree that some Battlestars have them, I have to contest the claim that all Battlestars, specifically the Galactica have them.
Here's why:
Firstly, if the Galactica has missiles, why does not she ever use them? In the "Hand of God" (an episode that many people claim proves the Galactica has missiles), it is clearly stated by Adama that the lasers are reconfigured so that they can attack the Baseship. Indeed, when the Galactica turns for another pass, Adama states that the lasers can fire ("Fire port lasers as she comes to bear" and "Forward lasers lock on"). While the special effects are the same as when the Pegasus attacks Basestars, we all know about how the series continually reused special effects.
It could be stated that the Galactica had run out missiles at this point, but I can not buy that. For a start, she had never used any since before the Peace Conference (if she had any), and certainly during the series the ship does not attack many Basestars head on.
Also the fact that the Pegasus had gone through a major fight and then survived two years before recontacting the Galactica, and still had missiles left to face a few more Cylon Baseships leads me to doubt this. I believe that the Pegasus was a field modification, but again there is no evidence for this, in fact evidence against, as if so, where did the missiles come from? The Cylons do not use these on their Baseships (well, actually they do "Hand of God", "Living Legend", although it is funny how Cylon missile launchers look exactly like their laser weapons), but it is clearly stated that no one has ever survived a trip to a Basestar before "Hand of God"), and , so the only other place I can think of, is it that the missiles come from the Cylon Ground Assault Batteries, but then Sheba stated that they hadn't actually landed, just flown over the place several times, so that is possibly out too.
The "Living Legend" also has a couple of other revelations. These include the fact that when Apollo is figuring out what Cain is planning, he states that the Pegasus has no weapons. Now, if missiles were a standard part of a Battlestars armament, why would he state this? He would know about the missiles, would not he?
Or does he 'state' this, instead just making a reference that the Basestars are armed? Re-re-rewatching these episodes I am not sure if he mentioned it casually or with alarm... I mean, when the Pegasus does fire it is missiles, he mentions the fact as if he knows about it after all. Still, the above point about the Galactica not ever using her weapons is still valid, even if this is not.
But we know that the Galactica is around 500 yahrens old, and we know that it has been modified and updated many times, so we can probably assume that other Battlestars have as well, so it is possible that the Pegasus got it is missiles as an update, but certainly the Galactica has not got that.
Again, to this question I say no. At no point do we have any evidence from the series that ships from this setting have shields. I would like to point out that when I say Shields, I mean protective force fields like those found in Star Wars or Star Trek - shields that protect a ship from enemy fire. The only shields we have in Battlestar Galactica are electronic defensive shields (from "The Living Legend" which I assume are more related to jamming and electronic warfare) and the shield which covers the main bridge view screen when someone shouts "Positive shield!". And that is it, other than small forcefields to guard cells and protect the air in landing bays. At no point are other shields or defensive forms of protection mentioned. Which means that to protect a ship, it would have to be covered in armour, and with the amount of damage that a ship can take, it seems tobe me that ships do indeed have fairly substantion armour.
In addition, this armour does seem to have some of the properties of shields. If you look carefully, when a ship the size of the Galactica is hit by weapons fire, a large section of the ships hull lights up. This could be because the armour is absorbing the incoming energy and then spreading that energy across a much wider area of the hull. This energy is then bleed back into space, much like a shield does. The only thing with armour is that you can not switch it on or off and it can not simply be bolstered by adding additional power from other sources. It also does not stop attacks until that attack has hit the actual ship, unlike normal shields which would stop the attack before it hit the ship.
If you study the warbook listings for ships when they flash up on the screen, it does give a shield rating. To me, this is the thickness and effectiveness of the actual armour involved, which is probably called a shield.
Another thing that people mention to prove that the Galactica has shields, is to point out that in the episode "Experiment in Terra", the Galactica puts a shield around the planet to stop the missiles. Well, watch the episode again. It is clearly stated that the Galactica uses its lasers to this effect.
John "In about three minutes, enough flying missiles are going to pass each other in the air to devastate four fifths of this planet beneath us."
Starbuck "The Galactica, her lasers!"
John "Precisely."
A little later, Adama then says "Battle stations, maximum laser power stand by" and then we get the graphics. So the Galactica can set up a forcefield type effect, but it is done with her lasers rather than with shielding technology.
Another difficult one this. We know that at the end of the Thousand Yahren War there were only five Battlestars left - the Galactica and the Atlantia are the only ones that have names corresponding to actual ships.
All, except the Galactica were destroyed at the Peace Conference at the Moon of Cimtar "Saga of a Star World".
Although the Triton, Acropolis and Pacifica are listed only in background comments, we do actually see five Battlestars, so is it fairly safe to assume that these names correspond to the missing Battlestars?
During the episode "Gun on Ice Planet Zero", we find out that the Columbia has already been destroyed, before the Peace Conference.
We find out later that the Pegasus is also around "Living Legend".
From "Take the Celestra" we find another name, the Rycon which was Commander Kronus's ship, destroyed at the Battle of the Cosmara Archipelago.
So that means that there have been at least 9 Battlestars around at various points in the Colonial history.
Knowing that the Galactica is at least 500 yahrens old, we can probably assume that there has been more at some point.
One thing we can safely put to the rest, is the theory that there were 12 Battlestars, one per Colony. This was never stated in the series nor even hinted at, and was a bit of fan fiction (I think stemming from the Colonial Warrior Technical Manual) that has stuck around. In fact, Glen Larson has only ever stated that they filmed around three Battlestars, and went on to say that they never said that their were only twelve Battlestars. Although I can see where the idea came from, there being twelve colonies, and there being a Quorum of Twelve, Adama being from Caprica and commander of the Galactica, and the President being from another colony and commanding the Atlantia.
The Solaria, Cerberus and the Prometheus are confirmed names from the Costume Department at New West, so they can be considered extra ships. All however were lost before the tragic Peace Conference.