Captain Seafort wrote:A few things:
1) Total build time for DS1 was about 2 years. Whether that was continuous or with extended tea breaks is unknown
Books quoted by Wookipedia said the construction started in 21BBY. We both know she is "operational" few days/weeks before the battle of Yavin. And it is stated Revenge of the Sith show the First Death Star in 19BBY, the movie canon go over the Expended Universe and the Death Star prototype near Kessel. The Force Unleashed in 2BBY show a Death Star still in completion.
If the book about Death Star talk about problems and delays, I don't know a source who said she had a total build time of just 2 years.
Captain Seafort wrote:2)The object seen at the end of RotS wasn't the first Deaths Star - the proportions are all wrong. It's either the Separatists' Great Weapon, or the Deaths Star prototype (or possibly both).
3) The record for a ship is the second Death Star: 900km across, and more than half finished within six months.
Star Wars.com, the most official source you can find, put them on the same class, so they can't be so different in size, but the second is clearly from a subclass. Just like the USS Nimitz at his commission and the USS George Bush who are different in many way but still the same size and many common parts. http://www.starwars.com/explore/encyclopedia/technology/deathstar/
The 900km size came only from a book, not from Star Wars.com who give the official size of movies ships and stations (like the 19Km of the Executor, long believed to be 8Km only by books author like Stackpole.) but don't state about the size of the space stations.
But Mimas, the "Death Star shaped moon" has a diameter of 396Km http://en.wikipedia.org/wiki/Mimas_(moon)
(a little surprising no? ^^)
edit: looking at Death Star II wookipedia page, a book and only a book said it was approved to build a second Death Star few times before the destruction of the first one. But still more than 2 years of construction before a little more than half of completion and no serious problem, thanks to Prince Xizor transporters... and with a building process well know after a first Death Star (and maybe the Maw's prototype).
If you want to ask me, this avatar is a resized version of "The War Come Home" by Davemetlesits found on DeviantArt