Building a Death Star with a bigger ventilation Shaft

Question

There's one thing I never got in Star Wars. The first Death Star was destroyed because there was a small ventilation shaft that lead to the core of the station and which would let only a small projectile through. So why would the Imperials rebuild it with a bigger ventilation shaft to allow ships to fly into it? It makes no sense, did they not learn the first time round?

And why did they not have better shields? OK, they did have a shield but it had to be generated from down on a planet. If I had given the location of the base to rebels to get them to come into a trap I would at least build a shield generator so if the planet one failed, which they thought it might, I would have a back up. So why didn't they have a second shield generator?

Answer 1

The second Death Star was in the process of being built; you cannot assume just because they could attack it by flying inside it to attack its reactor core that this means that they were building a 'bigger ventilation shaft' that would allow it to be attacked like that when completed.

The Endor-generated shield was a level of power above any shields we have seen in Star Wars. It was able to prevent any ship from approaching the Death Star - whereas the original appeared to have little or no shields, and relied on its other defenses. It had been designed to defend against capital ships approaching it and the rebels attacked with ships that were too small.

The fact that the shield generator was so powerful shows that the Empire had learnt from the original, and it's not entirely surprising to think that a shield generator to protect something of that size might require more power than the partially built Death Star could provide.

I do not think that we can see any oversight in the Death Star II design just because of the events in RotJ.

Answer 2

I don't see a problem here. The second Death Star was not yet completed (while the first one was). You could see the huge holes from far away.

Answer 3

The Empire did learn after the first go around. However, the second Death Star was unfinished and the Rebels were able to infiltrate it by flying into the unfinished super-structure.

From the script:

126 EXT/INT - SPACE BATTLE - FIGHTER AND DEATH STAR 126

Rebel fighters follow the Falcon across the surface of the Death Star to the unfinished portion, where they dive into the super-structure of the giant battle station, followed by many TIE fighters.

WEDGE I'm going in.

LANDO Here goes nothing.

Three X-wings lead the chase through the ever-narrowing shaft, followed by the Falcon and four other fighters, plus TIE fighters who continually fire at the Rebels. Lights reflect off the pilot's faces as they race through the dark shaft.

According to the Essential Guide to Vehicles and Vessels (1996):

Not only was the second Death Star larger and more deadly, but several flaws in the original design were corrected. The vulnerable thermal exhaust ports were replaced with millimeter-wide heat dispersion ducts, leaving no weak spots in this battle station's armor.

...

This new Death Star would have been invincible; the only way to stop it would have been to destroy it while it was still under construction.

...

A small team of Rebel commandos was able to enlist the Ewoks' aid and destroy the shield generator, thus allowing the Millenium Falcon, commanded by General Lando Calrissian, to fly inside the partially completed battle station and destroy its power core.

Answer 4

I would attribute this "inconsistency" to Lucas's writing. If you watch the original three movies now, from a retroactive point of view, there would just be a plethora of dubious and verisimilitude-devoid scenes.

Let's just say that it was a failure in writing and not burden the canon much.