PLANETARY DEFENSE | How to protect your world from invasion [FIXED]

Generic greetings and welcome to science insanity, a channel dedicated to bringing my love of sci-fi to you. Today we're covering planetary defenses, how they work, what they do and what the different types of them are. So settle in and get ready to learn how to protect your world from all the nasty, filthy, disgusting xeno filth trying to invade it.

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[be-noble]

Garrison Forces are like Locks: They make sure honest people stay that way!

[Girubev]

Another two things to touch on regarding megastructures: they take a very VERY long time to complete compared to other forms of defense, and they are quite likely to be detected during their build stage when they are at their most vulnerable as shown in Return of the Jedi. They're a sort of "win more" thing when it comes to game theory, because you would never invest the time and resources if your other defenses are weaker than a potential opponent because they would simply rush in and not let you complete it, if you're of equal strength you can't afford to divert said time and resources to not fall behind in the eternal arms race and become the weaker faction, and if you're the stronger faction then you never particularly needed the megastructure in the first place. They have their place when a faction is trying to futureproof itself from some unforeseen outside enemy like Stellaris' crises or stave off the inevitable turn of the wheel when their civilization collapses, but against one's immediate neighbors and rivals megastructural defenses seem to have more cons than pros.

[CaptainRhodor]

I just love the Fermi Steam Cannon as an anti-invasion weapon. Imagine the utter disrespect of smacking down a ship capable of interstellar or even intergalactic travel with a manhole cover traveling at the *_exit velocity of the solar system_*.

[Comicsluvr]

One of the things that may have been shown in Star Wars books or animated work, but not in the films, was the way the Empire wasted a lot of resources on overkill. Sure, a star destroyer is great as the backbone of a fleet or even as a single unit, but it's a waste when chasing down a handful of pirates or rebels. This is why most of the wet navies of Earth have warships for fighting and coast guards for anti-piracy and S&R operations.

[tickticktickBOOOOM]

Something else to mention that was overlooked here is building facilities deep inside a planet. You can mine resources, use them to make munitions, and build facilities in the cleared space, the deeper the better. Even if the enemy clears out your space-based defenses, if hatches keep appearing on the planet below and belching out missiles, railgun rounds, and attack craft into the orbitals and system beyond, it wouldn't do them much good. They'd need something Death Star tier to literally blow the planet apart if they want to fully control and utilize the system without constant streams of incoming fire.

[igncom]

I've always been fascinated by the idea of planetary defences so vast, that the planet beneath them is more like a colossal heat sink that the enemy attackers must overcome.

Unless the mass of the enemies heat sinks matches that of the defenders, then they might need alternative methods of nullifying the threat. And that's before the enemy starts recycling the heat for more power!

[HappyBeezerStudios]

I've always seen planetary defense as a multi layer setup.
From outside inwards:

- A fleet that can move around to intercept invaders, but also transport troops or relief materials. The ships can also move to other allied systems or run counter offenses. They are the mobile operation for all kinds of missions. From military, to exploration, to logistics.
The fleet would be bigger than what is in active service. Be it for refits and updates or simply to save costs. And if a ship gets damaged, pull it back and replace it with one from the mothballed reserves.

- Next with systems at the edge of the influence. So stations in solar orbit that can track and catch invaders if they just visit the system. Their use is also to guard the border and control traffic.

- Next would be orbital systems around any inhabited planets. A vast satellite array that can secure the orbit. They would be the main part of the defense and can be reinforced by fleet operations. Combined with orbital stations to dock and resupply ships.

- Next ground systems. Like a network of cannons or silos that can target orbit and airspace. Basically the last line of defense that isn't active for most of the time, but are cheap to build and activate.

- Infantry/robots/drones/etc would be placed on all layers. From crews to operate the stations, ships and cannons, to boarding parties and ground armies.

All of the space and ground systems would have not only weapons for attack, but also defensive features (point defense guns, shields, armor, etc)

And generally I would step away from any kind of massive super weapon outside of prestige projects. They are simply impractical.
They can only be at one place at a time, and enemy tactics might include luring it to a different place. Two simultaneous attacks at different places leave one of those places without super weapon.
Plus it puts lots of resources into one single thing. Resources that could be used to build a complete fleet of smaller structures that can be spread out to cover a vast region, or concentrated for a combined strike.

[damongraham]

I really like the "The Fleet in Being" idea. I love reading about a construction worker, lawyer, and doctor all receiving a letter from the government. Time to fulfill your promise of duty in their time of need. The three end up in the same warship as the bosun, captain, and doctor that is about 3 or even 5 generation older then what is currently deployed by the government. Since they have no time to update these old warships. The are place in units where one or two current gen warship are tied into their sensors to help the older gen warships to be able to throw more missiles or laser at one time. Making what you got work in the time you have.

[darth_dan]

I think there is actually so much more to talk about when it comes to "passive" or "other" defences.
When someone invades YOUR system, you have a lot of home advantage to potentially leverage.

Hidden instalations in asteroid belts or behind moons, industrial complexes ready to be retooled within hours to produce a swarm of low cost attack drones, portions of the fleet stationed off the beaten path ready to hit the enemy's flanks or rear...
There is so many possibilities there.

[viddarkking]

The ultimate in planetary defense The Behemoth Planetcraft.
AKA the planet that we made into a battleship.
Stellaris mods are fun.

[nitebones]

one thing to add to even the small defence stations they can be used as government check points for any ships coming into a system, scanning them and checking if there is any contra band so even if you are not at war they still have a use

[gilmadreth]

Primary tenant of Planetary Defense Platforms: I will keep shooting till my last breath because some dipshit didn't give me engines

[davidarimond]

14:25 missed opportunity here to use Space Balls planetary shield as an example.
“Remember kids stay off my fracking lawn unless you have the passcode! Boys remind me to change the code to my luggage!”

[linger]

This guy is like a mix of The Templin institute and sacred cow shipyards and it’s perfect.

[The_Viscount]

It is my personal analysis that the best fortifications aren't designed to stop an enemy attack, but to redirect it. The Maginot Line, while often cited as a failure, did exactly what it was designed to do: prevent a direct invasion across the Rhinelands. The intent was to encourage invading German armies to bypass the Maginot Line and instead attack through Belgium. The German army did indeed avoid the Maginot Line, but instead of attacking through Belgium, the bulk of the Nazi forces went through the Ardennes Forrest. This was not a failure of the Maginot Line but of the military planners who assumed the Ardennes were impassable.

So, designing a series of fortresses to encourage the enemy to take a predictable course is very useful if you properly predict their movements. This is why good recon is essential to defense as well. Ultimately, however, a mobile defense is often the most cost effective as it allows for fewer assets to defend a larger area. Even with gun platforms and the like being cheaper than full ships, the sheer number you need to fortify every star system quickly becomes cost prohibitive.

[limburgishmapping]

For most of its history Earth Space Dock in star trek was actually unarmed as United Earth did not trust a giant weapons platform being placed in its backyard even if it was a Federation facility.

[arbelico]

An interesting exercise.

- Ground troops: They are in charge of ground combat and endo-admospheric and exo-admospheric anti-air/ballistic defense (1 light second away).

- Aerospace Force: Based on the surface, it has fighters, bombers, and a network of satellites with sensors and weapons that can attack approaching ships or enemy troops on the planet's surface (in coordination with ground troops).

- Navy: Based on space stations, it carries out patrols in deep space, it has AWACS / ISR ships for early warning, the idea is to attack the enemy supply lines in case their force is much higher and the planet is expected to be besieged. Otherwise, destroy the attacking fleet.

[Mikos]

Really hoped to hear about the bigger downside of the static defense - it's inability to avoid long range bombardment. In Expanse railguns rely a lot on secrecy of their location, but in other examples - SW, ST, Halo...the locations of those static defenses are generally well known or can be obtained and as a result - bombarded safely from a distance, with a single ship being able to destroy a planet worth of defense structure, without ever getting in danger. It's somewhat explored in Thrawn series with the asteroid attack on Coruscant, but is generally applicable for all forms of static defense. Imagine spending centuries building a planet encompassing defense network, only for the whole planet to be glassed by millions of rounds that can be lined and timed by a single ship from beyond detection range. Overall static defense is worthless without the equivalent mobile element, the force of which it can multiply. But if it's multiplying a zero...

[tdofducksplays]

Played stelaris and used 4 of these tactics in one system, had a big bugger off station set up to shred armour, because it was built in a system with a pulsar that strips all shields, with a habitat in system with a large defence force with both a planetary shield (I don’t ask questions of how that works) and a FTL jammer, and then had a fleet that’s just ready to jump into any system to help defend.

[benjaminconnor]

Laser Web is my personal favorite defensive system, especially after reading "Live Free or Die" by John Ringo. Tears open just about anything and is a great "Castle Wall" for a star system. That and it can double up as a mining rig in it's down time, peeling asteroids like potatoes and selling them for scrap or making them into new mirrors. Self-Perpetuating to a point.