Reclaiming Earth from a Xenomorph infestation (RAR)

[General Zod]

Yeah actually it is because the hell is one battalion going to deal with an entire planetary surface?

How big is a battalion of guardsmen ?

If one battalion isn't enough, I can easily see the Imperium throwing enough guardsmen at the planet to kill off the Xenomorphs.

By a battalion I basically mean "a whole metric fuckload". I don't know the actual number that goes into one offhand.

[The Vortex Empire]

Yeah actually it is because the hell is one battalion going to deal with an entire planetary surface?

How big is a battalion of guardsmen ?

If one battalion isn't enough, I can easily see the Imperium throwing enough guardsmen at the planet to kill off the Xenomorphs.

By a battalion I basically mean "a whole metric fuckload". I don't know the actual number that goes into one offhand.

A modern battalion is a couple hundred men, but who knows what it is in the Imperium, given that they throw around armies made up of billions of men.

[Borgholio]

If we wanted to keep this as close to modern Earth Tech as possible, I'd probably go the Skynet route. Build a shit-ton of Terminators with orders to destroy any Xeno they find. Infected humans will be rushed to the nearest mobile surgical center if it is determined there is time to save them. If not, euthanize them as painlessly and quickly as possible, then burn the corpse.

[Starglider]

A major problem here is making sure that you really get every last xenomorph and most importantly egg cache. If you don't the problem will break out again constantly once the planet is resettled, and given that a single release already overran the planet likely it will happen again. Most sci-fi sensors are not up to the task of locating every trace of a particular organism across the entire planet. Trek sensors are probably better than typical and can identify specific organisms under good conditions, but there are too many factors that can cause interference and hence caches of eggs to be missed. You'd need redundant overlapping sweeps by a fleet of low-level sensor platforms, and even then it's hard to be sure. Small groups (e.g. Space Marine companies) are also out because personal weapons can't kill faster than a billion fast-breeding enemy organisms can make replacements, and conventional weapons heavy enough to overwhelm the breeding rate would do too much collateral damage to the biosphere.

Culture tech is definitely the way to go if it's available, self-replicating e-dust can literally blanket the planet with perfectly selective instant kill agent, and can even persist in the biosphere to make sure that even new xenos brought from offworld are quickly exterminated. E-dust can also do a lot to heal damage to the pre-existing biosphere (any surviving humans included) and rebuild infrastructure. From the Culture's point of view there's no need for anything more dangerous than a knife missile, as this is just a wildlife problem.

[Terralthra]

A major problem here is making sure that you really get every last xenomorph and most importantly egg cache. If you don't the problem will break out again constantly once the planet is resettled, and given that a single release already overran the planet likely it will happen again. Most sci-fi sensors are not up to the task of locating every trace of a particular organism across the entire planet. Trek sensors are probably better than typical and can identify specific organisms under good conditions, but there are too many factors that can cause interference and hence caches of eggs to be missed. You'd need redundant overlapping sweeps by a fleet of low-level sensor platforms, and even then it's hard to be sure. Small groups (e.g. Space Marine companies) are also out because personal weapons can't kill faster than a billion fast-breeding enemy organisms can make replacements, and conventional weapons heavy enough to overwhelm the breeding rate would do too much collateral damage to the biosphere.

Culture tech is definitely the way to go if it's available, self-replicating e-dust can literally blanket the planet with perfectly selective instant kill agent, and can even persist in the biosphere to make sure that even new xenos brought from offworld are quickly exterminated. E-dust can also do a lot to heal damage to the pre-existing biosphere (any surviving humans included) and rebuild infrastructure. From the Culture's point of view there's no need for anything more dangerous than a knife missile, as this is just a wildlife problem.

The only reason they might not just use e-dust and knife missiles and similar is that their panhumans would get to have some fun helping eliminate the xenomorphs, similar to the Restoria's panhuman-piloted anti-smatter spacecraft. The human mind does do some things particularly well, and it lets them feel useful. Other than such quality-of-life reasons, it's difficult to see why they wouldn't just displace anything xenomorph- or egg-shaped into the sun while reforming the biosphere.

[biostem]

It'd be pretty cool to see Skynet and its forces changing gear to fight the Xenomorphs - imagine that Skynet couldn't let the Xenos wipe out the humans, (for whatever reason), but the resistance was still actively fighting against its forces as well...

[bilateralrope]

A major problem here is making sure that you really get every last xenomorph and most importantly egg cache. If you don't the problem will break out again constantly once the planet is resettled, and given that a single release already overran the planet likely it will happen again.

True. Holding the planet while dealing with regular xenomorph outbreaks doesn't fit the scenario requirements. Which rules out the Imperium as they are more likely to decide that regular outbreaks are good practise for the local PDF.

But if the Imperium was determined to exterminate all the xenomorphs, they would probably release something to kill off the human population (and any other life capable of sustaining xenomorphs), wait a few decades for the xenomorphs to starve, then ship new colonists in.

[General Zod]

Evacuating as many humans as possible and then doing an exterminatus might be the way to go, even if it would leave the planet uninhabitable for awhile.

[Zixinus]

But that would be rather counterproductive to saving Earth in the first place. If nothing else, you want the planet habitable for humans after you are done.

[Zaune]

From what I know of the movies, Earth was only marginally habitable for humans even before the xenomorphs happened thanks to centuries of environmental destruction.

[Zixinus]

Yes, but it's still Earth and having an exterminatus is definitely going to leave it uninhabitable.

So, I think it's good to say that should be plan C or later.