Rebel Fleet at Endor

Darth PhysBod · Post by **Darth PhysBod** » 2003-11-04 06:10am

Note the number for each image/link corresponds to the frame number in the film. The aim is to estimate the rebel fleets velocity and deceleration (to an order of magnitude) on approach to Endor.

Firstly I’ve scaled the Bridge windows of the executor using the Vadar outfit as a reference (its 204 cm in height according to the SW/IJ Archives):

Top Bottom
Vadar: 342,142 342,188 dy=54 (204cm costume)
Viewport: 312,118 312,156 dy=38= 144cm

Using this to scale the Deathstar in this shot….

Left Right
Deathstar: 302,23 359,23 dx=56
Viewport: 351,8 351,49 dx=41

As the command deck is over 2m wide (going from the first shot) we can infer from the Bridge plan on p91 of the Technical journal that the bridge interior is at least 12m from viewport to the edge of the security foyer:

Viewport =41=144cm
Deathstar =56=196cm

Distance =900Km/(1.96m/12m)
= 5500Km

Deceleration

I’ve used the above shot from the Executor and the visible diameter of the Deathstar in the following shots to estimate the distance in the sequence where the rebel fleet appears to be decelerating on approach to Endor.

[Frames 134915-134980]
http://man1ac0.tripod.com/134915.txt
http://man1ac0.tripod.com/134920.txt
http://man1ac0.tripod.com/134925.txt
http://man1ac0.tripod.com/134930.txt
http://man1ac0.tripod.com/134935.txt
http://man1ac0.tripod.com/134940.txt
http://man1ac0.tripod.com/134945.txt
http://man1ac0.tripod.com/134950.txt
http://man1ac0.tripod.com/134955.txt
http://man1ac0.tripod.com/134960.txt
http://man1ac0.tripod.com/134965.txt
http://man1ac0.tripod.com/134970.txt
http://man1ac0.tripod.com/134975.txt
http://man1ac0.tripod.com/134980.txt

Pixel scaling and associated distances:
http://man1ac0.tripod.com/PixelScaling.txt

Thus a curve of Displacement vs. time can be plotted using the above data. In this case a polynomial was fitted to the data, the slope at any point gives the velocity at that point and included are several slopes:

Input used:
http://man1ac0.tripod.com/ROJD.txt

I’ve also used the data of the fit to get a corresponding velocity curve (differentiate the Displacement curve), and then again for the corresponding acceleration curve:

From all of the above it appears the Millennium Falcon and thus by extension the entire Rebel fleet (as nothing overtook/crashed into the Falcon) was decelerating in the thousands of Km/sec^2 order of magnitude.

Decelerating from slopes Red to Green added to the displacement curve (13,000 to 3900Km/sec, taking green to be the slope at frame 60) and assuming constant deceleration between (60 frames or 2.4 seconds), would require 3800Km/sec^2.

Red to blue (13,000 to 6500 Km/sec, frame 0 to 15) would require a constant deceleration of 11,000Km/sec^2.

The peak deceleration is possibly higher still (looking at the acceleration curve). The question is how the fleet achieves this deceleration with the apparent lack of any large thrusters/engines on the front of the ships.

phongn · Post by **phongn** » 2003-11-04 10:19am

Thrust deflection via EM fields? Most modern airliners deflect their thrust forwards while landing to slow down.

Knife · Post by **Knife** » 2003-11-04 01:01pm

The question is how the fleet achieves this deceleration with the apparent lack of any large thrusters/engines on the front of the ships.

We know that there is a seprate engine for hyper space travel, though the sub light engines apear to have something to do with the run up to hyperspace. Any way, what ever effect that puts, keeps, and then releases the ships to and from hyperspace are probably responsible for the sudden acceleration/deceleration and are not dependent on the sublight engines.

Long way of saying that I don't think the glowing engines have anything to do with the massive deceleration you speak of.

Connor MacLeod · Post by **Connor MacLeod** » 2003-11-04 05:09pm

Given that the ICS and EGV&V tend to place most capital/fighter scale accelerations in the thousands of gees range, its unlikely we're seeing thruster-based deceleration.

They might be using inertial dampers to decelerate. SWTC placed the ISD ID's at something around millions of gees, and we know from various sources (Slave 1 in Tales of the bounty Hunters, Luke's X-wing in Heir to the Empire, The Falcon charging the Avenger in TESB's galaxy guide from WEG, etc.) that Inertial Dampers can apparently decelerate a ship (at least relative to another massive object like a planet or some such - which makes sense given SW gravity seems to need something to push against usually.) ID tech is tightly related to hyperdrive function IIRC (which if it involves massive acceleration/deceleration, makes sense.)

I believe Wayne Poe and Curtis Saxton have speculated you can "run up" a ship to near-c using the hyperdrive without neccearily "crossing over" to FTL - Saxton specualted something like this occuring with the Millenium Falcon and a couple of other vessels in "The Hutt Gambit" during the battle of Nar Shaddaa over a hundred thousand kilometers, and Wayne speculated it might help explain the FAlcon's progress to Bespin in TESB.

Connor MacLeod · Post by **Connor MacLeod** » 2003-11-04 05:10pm

phongn wrote:Thrust deflection via EM fields? Most modern airliners deflect their thrust forwards while landing to slow down.

Might be possible but you're still left with the problem of the so called "thousands of gees limits" on ion engines.