Turbolasers in upper atmosphere

Post by **Vympel** » 2004-11-09 04:33am

SPOILER

I'm really sick of putting spoiler, as after all it's already freely available on the databank as to the Battle of Coruscant, but anyway, I thought a dedicated question would suffice; from the Databank entry for Grievous:-

In the final stages of the Clone Wars, Grievous orchestrated a daring strike against the heart of the Republic. His flagship led a fleet of massive warships to Coruscant, where an immense battle raged in the upper atmospheres of the capital world. The fighting had gone on long enough -- one way or another, this strike would lay the foundation for the end of the war. Grievous was determined to be victor, and hoped to add the lightsabers of the most famous Jedi warriors -- Anakin Skywalker and Obi-Wan Kenobi -- to his grisly collection.

We have some post-production notes from SW.com (hyperspace) that indicate:

Gossamer wisps and contrails streak by, providing a sense of speed, and dark black smoke belches from a burning starship - something we haven't seen before in a space battle. "John Knoll says that space starts at 60 miles up," explains Weitzberg. "We're at 59 miles up."

What would be the effect of turbolasers in the upper atmosphere at that altitude?

VT-16 · Post by **VT-16** » 2004-11-09 04:36am

You see alot of turbolaser fire in the trailer, it doesn´t appear to be much different from the normal space combat.

If there´s something different that would happen in RL, it looks like they ignored it.

nasor · Post by **nasor** » 2004-11-09 10:20am

If heavy turbolasers are really supposed to be in the 200 GT range, it doesn’t seem possible to have a large-scale battle in the upper atmosphere of a planet without utterly annihilating said planet. Even a few stray shots (and there would probably be many in such a battle) striking the surface would pretty much spell doom for anyone in that hemisphere.

Lord Revan · Post by **Lord Revan** » 2004-11-09 10:23am

nasor wrote:If heavy turbolasers are really supposed to be in the 200 GT range, it doesn’t seem possible to have a large-scale battle in the upper atmosphere of a planet without utterly annihilating said planet. Even a few stray shots (and there would probably be many in such a battle) striking the surface would pretty much spell doom for anyone in that hemisphere.

Medium TLs and it's 200GT max. Also there might be a shield between the ships and the surface.

Luzifer's right hand · Post by **Luzifer's right hand** » 2004-11-09 10:29am

The upper atmosphere is the Thermosphere (85 km+)afaik.
It's possiple that the planetary shield is closer to the surface of the planet.

The Silence and I · Post by **The Silence and I** » 2004-11-09 01:44pm

Somewhat possible, but Alderaan's shield extended much farther from the planet surface than 60 or so miles.

Crazedwraith · Post by **Crazedwraith** » 2004-11-09 01:48pm

The Silence and I wrote:Somewhat possible, but Alderaan's shield extended much farther from the planet surface than 60 or so miles.

Well we know that coruscant has a double layer of shields. It's possible nay likely the fightings inbetween them.

Post by **Darth Wong** » 2004-11-09 02:14pm

The upper atmosphere actually extends out to hundreds of kilometres, but it becomes thin enough for short-life satellites above 100km. But the pictures I saw of the conflict seemed to suggest a considerably higher altitude than 60 miles, since I think I recall seeing the arc of curvature of the planet and it looked like they were much higher up.

Anyway, since we know from the ICS that SW shields use neutrino radiators to dump energy, the effect in atmosphere wouldn't be that much different than the effect in space unless turbolasers themselves interact strongly with the thin atmosphere, and that seems unlikely. High-altitude atmosphere is essentially transparent to certain kinds of radiation already.

The Silence and I · Post by **The Silence and I** » 2004-11-09 06:32pm

Crazedwraith wrote:
The Silence and I wrote:Somewhat possible, but Alderaan's shield extended much farther from the planet surface than 60 or so miles.
Well we know that coruscant has a double layer of shields. It's possible nay likely the fightings inbetween them.

I agree with possible, but why do you find it likely the fighting is between the shields? From the admittedly limited footage we have I have seen zero evidence Coruscant is under the massive bombardment needed to bring down its shields. If the attacking force took down the outer shield, why stop there? They have gained nothing unless the inner shield is down as well.
If the attacking force arrived too early for Coruscant to raise shields, then neither shield would be up.
I find these hypothoetical scenarios likely:
A) Both shields are up and the battle is above them
B) Both shields were raised and the fleet is bombarding them
C) Neither shield was raised in time and the fleet makes sure they won't become raised.
D) The inner shield was raised in time but not the outer shield.

Now, going by what we saw:
If A, then we ask why the shield is so close to the planet surface
If B, then we ask why no one is bombarding what appears to be the inner shield
If D, then we ask why the inner shield was raised first--the atmosphere apparently extends beyond it, and risks severe damage from the battle (repairable yes, but no one wants to spend extra money on restocking the atmosphere...).
Of these scenarios C makes more sense; what scenario(s) do you envision?

Illuminatus Primus · Post by **Illuminatus Primus** » 2004-11-09 07:35pm

We're going to have to explain away any combustion or contrails - that won't happen unless you're down in the stratosphere; that about tops off in the mesosphere and then we'd be getting things looking like high-altitude detonations of nukes each time a TL hit home.

Lord Poe · Post by **Lord Poe** » 2004-11-09 08:01pm

Well, there's always the argument that the Seperatists are trying to take Coruscant, not destroy it. So why would they max out their TLs?

Post by **Vympel** » 2004-11-09 08:40pm

It's a pretty safe bet that the shields are down. If they had been up, how would the Separatists have kidnapped Palpatine/Sidious? Or, at this point, Coruscant simply didn't have shields at all, unless PT/CW EU says otherwise.

As to weapons fire of any type striking the planet, for some reason I don't think there'll be much evidence of that. I doubt GL would bother to show it.

That the battle is taking place too high to actually be 'upper atmosphere' is supported by another quote from the post-notes, where one of the FX guys (I think, I'm at work so I don't have the quote) speculates that Coruscant has an extra layer of artificial atmosphere or some such 'what if'.

Post by **Vympel** » 2004-11-10 02:50am

Those gossamer wisps and contrails deleted?

Another visual effect that seemed unclear in these early passes was a peculiar shockwave that sheds off the Jedi fighters as they begin their precipitous dive. "What I really liked in Pearl Harbor was that, whenever they fire tracers, you see a trail of smoke behind the shot. And whenever you're flying with the plane and they fire, the smoke they leave behind gives you tremendous speed reference. So, I thought, what if we could have something like that in this environment?" he says.

"Obviously, this is outer space, so you can't have it be atmospheric. But what if Coruscant had an extra atmospheric layer that they put artificially to protect the planet from gamma rays or whatever? So maybe this layer chemically reacts with the fighter's engines once they pass a triple-supersonic sound barrier, making a ripple," he postulates. Whatever the rationalization, the visual effect was intriguing, but it was ultimately left out. "I don't think George objected to the idea. If they had fired in this shot, I would have added tracers -- lasers with tracers -- but he said, no, they don't fire."

This is from the June 09 post-notes. The "59 miles up" post notes is from May. Looks like those upper atmospheric visual effects may have been dropped altogether.

Icehawk · Post by **Icehawk** » 2004-11-10 02:59am

Why the fuck would bright visible bolts need any sort of "tracer effect"?

You already get a perfect "speed reference" from the bolts themselves. Its mindless illogical "creative" shit like this that pisses me off about some people who make movies. I really hope they don't try to sneak any of that crap in.

Post by **Vympel** » 2004-11-10 03:16am

Icehawk wrote:Why the fuck would bright visible bolts need any sort of "tracer effect"? You already get a perfect "speed reference" from the bolts themselves. Its mindless illogical "creative" shit like this that pisses me off about some people who make movies. I really hope they don't try to sneak any of that crap in.

I think they're using the wrong terminology- the context means a trail of smoke behind the shot, rather than what we understand to be a tracer. Either way, it's a pointless, stupid effect and I'm glad we don't see either these 'ripples' from the fighters or these smoke 'tracers' from their shots. They shouldn't be emulating damn Pearl Harbour in any way, shape or form regardless.

VT-16 · Post by **VT-16** » 2004-11-10 03:23am

Icehawk wrote:Why the fuck would bright visible bolts need any sort of "tracer effect"? You already get a perfect "speed reference" from the bolts themselves. Its mindless illogical "creative" shit like this that pisses me off about some people who make movies. I really hope they don't try to sneak any of that crap in.

Prepare for the worst, and hope for the best, I say.

Post by **NecronLord** » 2004-11-10 04:21am

Lord Poe wrote:Well, there's always the argument that the Seperatists are trying to take Coruscant, not destroy it. So why would they max out their TLs?

Because they want to actually do some damage to the other side?

Dialling your power down to 100Mt and shooting at a shielded trade federation core ship is the definition of futility.

The only way I can think of that would work is both sides engaging only with ion cannons, and the trailer already over-rides that.... but the Venator shot we've seen shows it only firing blue beams, admittedly against the vessel holding the Chancellor, so that's to be expected.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-11-10 04:27am

nasor wrote:If heavy turbolasers are really supposed to be in the 200 GT range, it doesn’t seem possible to have a large-scale battle in the upper atmosphere of a planet without utterly annihilating said planet. Even a few stray shots (and there would probably be many in such a battle) striking the surface would pretty much spell doom for anyone in that hemisphere.

Recall that firing a turbolaser isn't like dropping a nuclear bomb.

Post by **NecronLord** » 2004-11-10 04:29am

Spanky The Dolphin wrote:
nasor wrote:If heavy turbolasers are really supposed to be in the 200 GT range, it doesn’t seem possible to have a large-scale battle in the upper atmosphere of a planet without utterly annihilating said planet. Even a few stray shots (and there would probably be many in such a battle) striking the surface would pretty much spell doom for anyone in that hemisphere.
Recall that firing a turbolaser isn't like dropping a nuclear bomb.

This depends doen't it. I'd expect to see some atmosphere-interaction from them. Or rather, hear it.

Personally, I have the feeling that at some point a turbolaser will miss in this film, and do precisely 0 significant damage. Call me a pessimist...

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-11-10 04:31am

Unless they decided to do insert shots of said damage, I don't expect to see any, either.

Or are you expecting massive explosions from orbit?

Post by **NecronLord** » 2004-11-10 04:37am

Spanky The Dolphin wrote:Unless they decided to do insert shots of said damage, I don't expect to see any, either.

Or are you expecting massive explosions from orbit?

Which is kind of neccessery for a BDZ, yes. Given that if they're not firing at full power, there's no way they're going to be able to damage each other behind shields, a stray shot should create a massive explosion like this one, but I very much doubt it will.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-11-10 04:40am

Bah...

Post by **NecronLord** » 2004-11-10 04:44am

I've been stung too many times by Stargate's feeble orbital bombardments to hold much faith in the abilities of film-makers to comprehend the power advanced space ship weapons should unleash.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-11-10 04:46am

Well maybe they'll carefully blow the shit out of each other.

Post by **Vympel** » 2004-11-10 07:24am

Personally, I have the feeling that at some point a turbolaser will miss in this film, and do precisely 0 significant damage. Call me a pessimist...

I call you a pessimist. I just don't see them bothering to track a turbolaser as it goes hurtling down to the planet's surface to do nothing. In fact, the chances of a heavy weapon striking Coruscant are quite low- all the pictures of the battle show ships *above* (as opposed to in front of) the curvature of Coruscant, and as we all know, the heavy weapons of Republic/Imperial warships are all on the dorsal strucutre.