DSII it's size and orbit around Endor

Crown · Post by **Crown** » 2004-06-05 10:20am

Lord Poe wrote:BTW, our new pal "Gary" on the sw.com message boards started a thread earlier here:

"Pablo (suck suck suck slurp) is right about Endor (proof inside)"

http://forums.starwars.com/thread.jsp?f ... ead=175666

I think a lot of people took Pablo's comments on the "Endor Holocaust" theory the wrong way, and I think a big part of the problem is that everyone assumed that Saxton was thorough and accurate in his analysis.

Unfortunately, there are several critical oversights in his analysis. For complete details, click here:

http://swrpgnetwork.com/entry.php?s=&id=1846

There are still some additional details I plan on adding to this article (e.g., I've found other evidence from the films that verifies my initial findings and further undermines Saxton's thesis), so if you're interested you might check back in a few days or a week for an update.

If you have comments or critiques, I'd love to hear it -- but please do *not* resort to an "Appeal to Authority" argument. It doesn't matter if Saxton has a PhD (i.e., his thesis should stand on its own merits, not his title). I'm only a few hours short of my PhD, anyway, so I'm not easily impressed.

From the guys analysis I quote the following;

Therefore, even with this crude estimate of size, the Second Death Star’s orbit is an absolute minimum of 38,824.7 km in radius, putting it at an altitude of 33,624.7 km over the surface of Endor. This is substantially more than Saxton’s estimate (2,000 km altitude over Endor).

The only thing here is; where does Dr Saxton actually state that the DSII is only 2000km above Endor?

Anyway, my point is that the more accurate figure of about 34,235.59 km (measured from the centre of Endor) is correct.

Assumptions;

Radius of Endor (Dr Saxton's) 5200km
Gravitational constant of Endor (Saxton) 0.8g
Length of a 'day' on Endor (arbitary guess of mine) 24hrs

I determined this seperately and independantly of this gentleman. This isn't using any kind of scaling bullshit, pixel counting mumbo jumbo. This is using Dr Saxton's Endor facts; 5200km radius, and 0.8g. Basically I figured out the required endor-syncronous orbit for the DSII to remain above the shield projector all the time. This of course assumes a 'day' on Endor (i.e. the time it takes to complete one full revolution) to be 24hrs.

In order to get an orbit of DSII only 2000km above the surface of Endor, then the length of an Endor day would need to be between 2 and 3 hours.

What affect this actually has on the scaling of the DSII relative to Endor, I'll let others decide.

Although I will point out that this gentleman does ignore Dr Saxton's use of the Executor impacting on the DSII as further evidence, and the fact that while the effects of his 180km DSII blowing up over Endor wouldn't be as bad as the 900km one they still would be fucking terrible, but hey.

EDIT :: I split this post (yes my own post) from here. I think that it deserves it's own dedicated discussion and it shouldn't be lost in all the other things going on in Ender's thread.

EDIT :: Re-structured post making it more legible.

Crown · Post by **Crown** » 2004-06-05 10:31am

Oh and consequently if we go by the radius that Mr Gary M. Sarli derived (38,824.7 km from the centre of Endor), that would mean that Endor would have a 'day' slightly shy of 39 hrs.

Crown · Post by **Crown** » 2004-06-05 10:34am

So yeah, I guess the first question is Does Dr Saxton actually claim that the DSII is only 2000km above the surface of Endor?

Galvatron · Post by **Galvatron** » 2004-06-05 10:47am

Crown wrote:So yeah, I guess the first question is Does Dr Saxton actually claim that the DSII is only 2000km above the surface of Endor?

Yes.

"The Death Star II was in a very low orbit. According to geometric studies, the construction site was at an altitude which put its orbit within a double-radius of the moon's centre. A likely estimate for the moon's radius is 5200km, based on the surface gravity and realistic ranges of planetary composition. Assuming this scale, the orbital geometry is such that the battle station is only another 2000km above the surface."

Crown · Post by **Crown** » 2004-06-05 10:55am

Galvatron wrote:
Crown wrote:So yeah, I guess the first question is Does Dr Saxton actually claim that the DSII is only 2000km above the surface of Endor?
Yes.

"The Death Star II was in a very low orbit. According to geometric studies, the construction site was at an altitude which put its orbit within a double-radius of the moon's centre. A likely estimate for the moon's radius is 5200km, based on the surface gravity and realistic ranges of planetary composition. Assuming this scale, the orbital geometry is such that the battle station is only another 2000km above the surface."

Your kidding?!

This means that it is vulnerable (between it and the shield generator will be Endor) at least once every 1.5 for about 1 hour ... something is rotten in the state of Endor.

The Endor moon does not revolve once about it's axis once in 2-3 hours, does it?

Crown · Post by **Crown** » 2004-06-05 10:59am

Wait, don't worry, he resolves that problem. Well I guess that this thread has answered its self (my initial post). What about this guy's webpage then?

McC · Post by **McC** » 2004-06-05 11:55am

Crown wrote:This means that it is vulnerable (between it and the shield generator will be Endor) at least once every 1.5 for about 1 hour ... something is rotten in the state of Endor.

The Endor moon does not revolve once about it's axis once in 2-3 hours, does it?

Maybe I'm missing something important, but why does the orbital altitude relate at all to the rotational period of Endor? Is there a fixed velocity in question that I don't know about?

McC · Post by **McC** » 2004-06-05 12:02pm

Also, his argument about the size being 160km rather than 900km is pretty compelling...is it flawed in some way that I'm missing? I'm not talking about calculating the size based on Endor or whatever, but rather based on the same methods that Dr. Saxton used -- scaling the trench and the shuttle bays. Also, has anyone showed this site to Dr. Saxton to get his feedback?

Illuminatus Primus · Post by **Illuminatus Primus** » 2004-06-05 12:26pm

The orbit of the Death Star II is not a normal geosynchronous orbit.

It is held in place to rotate slower than its altitude would imply. Hence Saxton's suggestion that a repulsor/tractor gimmick would've been necessary to hold the DS II up at such a low velocity.

McC · Post by **McC** » 2004-06-05 12:34pm

Oh, I see now. The orbital speed of the DSII at that altitude required to maintain its position over the shield is too low to actually maintain orbit, is that it?

Illuminatus Primus · Post by **Illuminatus Primus** » 2004-06-05 12:36pm

Yeah, a natural orbit at that altitude would be MUCH faster, but not maintain its position over the shield generator.

The gimmick also explains away the lack of noticable tidal effects and such.

McC · Post by **McC** » 2004-06-05 12:41pm

That's cool, and makes some good sense, too. What about when the shield generator (which would presumably contain the hardware) goes up? Would the DSII start falling/effect major tidal forces?

Also, what would the implication of the tidal forces/orbital velocity be if this Gary guy is right?

Illuminatus Primus · Post by **Illuminatus Primus** » 2004-06-05 12:57pm

Well we don't know if the Death Star's sublight drives were operational yet; presumably if they were the Death Star could acclerate into a standard orbit under its own power.

seanrobertson · Post by **seanrobertson** » 2004-06-05 01:40pm

McC wrote:Also, his argument about the size being 160km rather than 900km is pretty compelling...is it flawed in some way that I'm missing? I'm not talking about calculating the size based on Endor or whatever, but rather based on the same methods that Dr. Saxton used -- scaling the trench and the shuttle bays.

Yep, it's flawed. Look at the thread again

Lodz (that's me) took him to task on his shuttlebay scaling. His estimate for the Lambda's total width was too low, so his "Vader hangar" dimensions were also too low; that, in turn, meant his measurement of the trench's height was wrong, and so on.

He conceded that on page 11, FWIW.

McC · Post by **McC** » 2004-06-05 03:04pm

Ok. I'm not sure to which page 11 you're referring, though. The thread I know of in the official forums is only six posts long, and the 13-page Lucasfilm To Fans thread here is 13, but I didn't see you post on page 11 there either. What am I missing?

seanrobertson · Post by **seanrobertson** » 2004-06-05 05:39pm

McC wrote:Ok. I'm not sure to which page 11 you're referring, though. The thread I know of in the official forums is only six posts long, and the 13-page Lucasfilm To Fans thread here is 13, but I didn't see you post on page 11 there either. What am I missing?

Nothing, Ryan--it's my bad. I was talking about this thread. D'oH!

http://forums.starwars.com/thread.jsp?f ... =105&msRan

My apologies

McC · Post by **McC** » 2004-06-05 07:05pm

Ah, interesting. I see Mike has jumped in there too.

One thing that gets me is all these people who think debris "burns up" in the atmosphere. It does -- but "burning up" doesn't mean it goes away.

It just means it's a gas rather than a solid, or has become a fine enough solid such that it is no longer discernable as a single object. Conservation of Mass; it doesn't just 'go away.' *sigh* I'd mention that, but it seems like it'd be a waste of time over there.

Crown · Post by **Crown** » 2004-06-05 07:43pm

seanrobertson wrote:
McC wrote:Ok. I'm not sure to which page 11 you're referring, though. The thread I know of in the official forums is only six posts long, and the 13-page Lucasfilm To Fans thread here is 13, but I didn't see you post on page 11 there either. What am I missing?
Nothing, Ryan--it's my bad. I was talking about this thread. D'oH!

http://forums.starwars.com/thread.jsp?f ... =105&msRan

My apologies

He still hasn't conceeded on the orbit of Endor to Mike though, which Mike notes is the linchpin of his arguement.

Crown · Post by **Crown** » 2004-06-05 07:46pm

McC wrote:
Crown wrote:This means that it is vulnerable (between it and the shield generator will be Endor) at least once every 1.5 for about 1 hour ... something is rotten in the state of Endor.

The Endor moon does not revolve once about it's axis once in 2-3 hours, does it?
Maybe I'm missing something important, but why does the orbital altitude relate at all to the rotational period of Endor? Is there a fixed velocity in question that I don't know about?

I was assuming that the DSII needed to be at an Endor-synchronise orbit - that is always above the same point on Endor's surface. But Dr Saxton resolved this issue by pointing out that the shiled generator probably held gravity tech to keep the DSII up.

Yes I know you got it later, just making sure that anyone else reading this and had the same question would get it too.

seanrobertson · Post by **seanrobertson** » 2004-06-05 08:39pm

Crown wrote: He still hasn't conceeded on the orbit of Endor to Mike though, which Mike notes is the linchpin of his arguement.

It pretty much is.

The DS's scale itself (and related considerations) are secondary to the orbit, and that's probably the reason I found that part of Sarli's document so irritating. It was clear he was doing everything he could to slam Curtis' take on Endor.

As far as Sarli conceding to the Wongian war machine...give it another 18 hours or so

Crown · Post by **Crown** » 2004-06-06 02:37am

Wow.

Mike and Brian are kicking all sort of ass in that thread!

Mange · Post by **Mange** » 2004-06-06 03:49am

Scaling the DSII and Endor is extremely difficult since there aren't many visual references. Last year I tried to measure the DSII with measurements based on the trench and the hangars within the trench. I made several printouts and studied pictures of the full DSII and found that the size is between 151 and 165 kilometers in diameter. However, it's possible that dr. Saxton is correct that the trench is located within a "supertrench" as one of the matte paintings on his site shows. Darkstar has tried to challenge this piece of evidence, but IMO he falls short (like he always does). This would mean that the hangar bay in which Vader's shuttle lands, lies deeper within the super trench.
I think it's important not to completely disregard the statements made by the model builders in the Starlog magazine.

EDIT: Perhaps I should also point out that these measurements are difficult to perform due to geometrical issues, in other words, the results aren't that trustworthy.

vakundok · Post by **vakundok** » 2004-06-06 06:24am

I also tried that. I got the result of app 1700 m for the trench height and I extrapolated it to the diameter of the DS through the rebell hologram (it is interesting, but it appears that in the emperor's throne room, there is a different (more finished like) DS image) and I got 320- 340 kms as diameter (without the supertrench theory). If I remember well, I also got similar result through DS2 screencap images. (I do not know why Dr Saxton used only the middle of the DS image to create a lower limt from the trench when the edges culd have been used to get a correct ratio.) I also tried to use the Executor crash scene, but it resulted many (around ten) thousands km.
Then I rejected the project and decided not to go further before I get the final edition (I hope it will be the DVD

.)

McC · Post by **McC** » 2004-06-06 12:54pm

One interesting point that I saw and have started thinking about is the fact that the DSII was only half finished. Normally, this is used to reduce the volume of the material striking Endor by half. However, it is the half that is facing Endor in its standard orbit that is largely incomplete, and as a result this figure would be even lower. The common rebuttal to this is that the DSII was taking up position to fire at Endor at the time (as stated in the novel). Still, I'm kinda curious how the numbers would turn out if this geometry was taken into consideration without factoring in the turning-to-shoot-at-Endor part. Doesn't really yield anything useful, given that the DSII was turning, but it'd be interesting to see as a "what if" anyway.

Illuminatus Primus · Post by **Illuminatus Primus** » 2004-06-06 02:09pm

McC wrote:One interesting point that I saw and have started thinking about is the fact that the DSII was only half finished. Normally, this is used to reduce the volume of the material striking Endor by half. However, it is the half that is facing Endor in its standard orbit that is largely incomplete, and as a result this figure would be even lower. The common rebuttal to this is that the DSII was taking up position to fire at Endor at the time (as stated in the novel). Still, I'm kinda curious how the numbers would turn out if this geometry was taken into consideration without factoring in the turning-to-shoot-at-Endor part. Doesn't really yield anything useful, given that the DSII was turning, but it'd be interesting to see as a "what if" anyway.

The Death Star as viewed from the surface was not the incomplete side.