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This topic has moved here: Subject: Planetary Defenses
  • Subject: Planetary Defenses
Subject: Planetary Defenses

What are the cons of having planetary defenses in orbit around a planet?

Why wouldn't the UNSC just have SMACs other defense systems located on the surface of a planet?

  • 06.25.2011 12:21 PM PDT

Posted by: CultMiester4000
I'm not really an Apple person (Bananas forever) but damn, that's kinda sad.

Imagine a massive earthquake every time you fired.

Yeah.

Mass X Acceleration folks.

  • 06.25.2011 12:25 PM PDT

Yes... I can dodge ducks... and slow moving bullets.

And additionally the slug/projectile of the S/MAC would be affected by the atmosphere thus resulting in less force delivered when the slug/projectile hits something

  • 06.25.2011 9:01 PM PDT

"There is no time for peace. No respite. No forgiveness. There is only WAR!"


Posted by: ParagonRenegade
Imagine a massive earthquake every time you fired.

Yeah.

Mass X Acceleration folks.



theres no earthquakes involved . . .

MAC Magnetically Accelerated Cannon. the 500,000 ton projectile is launched at 20% the speed of light using no explosive material.

the only real problems are powering the cannon. getting a 500,000 ton projectile into space loading said projectiles into the cannon at a sustainable rate. and rotating the ENTIRE station to adjust for targets, while keeping its orbit.

  • 06.25.2011 11:59 PM PDT
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Posted by: evilcam
Bobcast is paid in MILF blind dates.

Posted by: Smartman91

Posted by: ParagonRenegade
Imagine a massive earthquake every time you fired.

Yeah.

Mass X Acceleration folks.



theres no earthquakes involved . . .

MAC Magnetically Accelerated Cannon. the 500,000 ton projectile is launched at 20% the speed of light using no explosive material.

the only real problems are powering the cannon. getting a 500,000 ton projectile into space loading said projectiles into the cannon at a sustainable rate. and rotating the ENTIRE station to adjust for targets, while keeping its orbit.


500,000 ton slug? The highest I've ever read was 3,000 ton for the Reach SMAC and 600 for a ship-based MAC.

  • 06.26.2011 1:38 AM PDT
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UWG

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ZedFish's Forerunner Rickroll.

I don't think there's any limitations to them, besides the massive amounts of power required to fire them. They must use preposterous amounts of energy to run a charge through coils up the barrel to magnetically accelerate the slug.

I don't think recoil would be a problem, because there are no explosions or any other physical forces used to propel the slugs that could 'push' the station back towards the planet.

  • 06.26.2011 3:44 AM PDT

less stress on SMAC's in zero gee.

In orbit, Reach's gravitation pull will have a smaller effect when firing at extreme ranges.

Also the extraordinary friction from Reach's atmosphere would slow down the slug.

The EM field produced from SMAC may interfere with surrounding elecronics, so they would need to keep them isolated, using up a lot of land.

[Edited on 06.26.2011 4:00 AM PDT]

  • 06.26.2011 4:00 AM PDT
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Every action causes reaction - as usual dynamics law :P
When you put a force to accelerate projectile similar force works on the barrel, even if you are not using any conventional propellant.

There is no drag of the barrel during shot because SMAC is into space where gravity is less affecting it.

Well, according what I heard ODS (Orbital Defense Stations) have thrusters which are used during the shot. ODS is located on geostationary orbit. It is possible to keep orbital position of the entire ODS.

Projectile launched from SMAC needs large amounts of energy that are delivered from onground power plants via (my speculations) microwaves or other wireless way (even today it is possible). Additionally ODS can fire projectiles (I think much lighter, I would say few tons) towards the planets surface (H:R when Covi Corvette was destroyed near base?).

There were 25 ODS over Reach - according Halo: Fall of The Reach. In Halo 2 was said that over Earth were 300 ODS - not all fully functional.

  • 06.26.2011 4:24 AM PDT

not planet-side because the opposing forces generated by firing such a large projectile at such a high velocity would create some funky local geological problems more than likely, two the cannon itself is enormous so putting it somewhere would be challenging and three it would loose its ability to change orientation, if you had them ground-side you'd more than likely have to bury the vast majority of the gun, which would hugely limit its firing direction to more or less directly in-front of the cannon.

also having them ground-side means the enemy is landing while taking care of the cannons, as opposed to in reasonably high orbit, soon as one gets into the atmosphere would imagine that the cannons (unless you were stupid enough to approach directly above them!) would become all but useless. though newtons laws do suggest that all actions have an equal and opposite reaction would be inclined to think that recoil from a coil-gun would be 'different' in the way it behaved perhaps, would likely be smaller amounts of longer duration recoil as the projectile gets accelerated along the whole barrel rather than the sudden and powerful recoil of a weapon with propellant, just a thought since never fired an substantial coil-gun.

  • 06.26.2011 4:43 AM PDT
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Well, I fired coil-gun (on Warsaw University of Technology few crazy students build small coil-gun or I would say coil-rifle), recoil is smaller than in standard weapons, but still significant (projectile is short range and muzzle velocity is twice of that of air gun, projectile caliber is 10mm, aprox. 20g). It's hard to say what it would look like on larger scale (that thing what I used had aprox. 15-20cm barrel).

1). I said that it would be smaller round, not 3000t! I think, it would be something like Onager round (or larger) with higher velocity (Onager fired at velocity aprox. 15000 m/s - 1.1GJ of energy).
Projectile 1t with speed of 3000 km/s (1% of light speed) delivers 100 times less energy than 100t projectile fired from destroyer class MAC gun. Pillar of Autumn was equiped with MAC capable to fire 3 rounds, each round had mass of 180t.
For me is still possible in this matter, especially that MAC round was approved to destroy Spire.

2), 3). Well, I think it is not a problem. Imagine using only one gun at a time, to aim the target you use orientation of ODP - thrusters.

Well, planet side MACs may be for security reasons. You know that Covi had stealth corvettes and UNSC had also stealth ships (rebels may also have similar). You can track target via radar if it is not jammed. In Halo: Reach no one saw incoming Covenant corvette which deployed Spire and masked approach of Assault Carrier. Humans realized threat like that is possible.
Military personell have this tendency to follow rule: Victoria amant preparatio.

MAC platforms above Reach were in too small number to cover whole planet. UNSC prabobly placed them near high priority targets such as military base, power plant.
Using ground-side MAC guns was prabobly much safer than deploying nuclear charge into the same area.

Still, most of this is still speculated.

  • 06.26.2011 6:16 AM PDT