Imagine that you're the admiral of a fleet of warships in orbit around Saturn. You need to capture targets on Titan, the largest moon. (This could also be applied to, say, Venus or one of the gas giants. This is an example. EDIT: this has been pointed out to me as false. This could work on Earth or Titan; that's about it.) You realize that your opponents live in airships (filled with hot air, not helium/hydrogen), not surface habitats!
This makes invasion extremely tricky, as you have no airships with which to board these ships. Instead, you decide to try to pop the envelopes from your comfy orbit.
The ideal result
- The airships have all been forced to land.
- Few, if any, lives are lost. (in other words, killing them all is not an option. Just put a small hole in the balloon so that they can't keep the inside hot enough to stay afloat without massive energy expenditures.)
- Minimal resources are expended. (so nix on taking a troop transport and crashing into the envelope. Using just a projectile dropped from orbit is ideal.)
- The life support of the habitats still works, so the fleet isn't forced to choose between genocide or rescuing thousands of people.
Please note that the standard tools the fleet has for orbital are not very great for the job because they are massive, heavy "Rods from God" made for absolutely obliterating surface targets. You will need to repurpose an object you already have to be able to complete the mission.
I've been asked to give more information on the resources available.
To respond to @DWKraus's specific questions:
- The tech difference is... interesting. To put it simply, the Titaneans in my story don't have all the tech that the attackers do, but they know what it does and how to exploit weaknesses in that tech. See another question of mine about this story: How would one hack a battleship in space warfare?
- They don't care a ton about deaths, ideologically, but their goal is to be in control, not to destroy. They don't want the Titaneans dead, they want them to come under their rule.
- Flight packs and drones are viable solutions, too! Orbital bombardment was the best solution I could think of on my own, but I am open to more creative ways to pop a hole in the envelope. The main limitation is that the resources used need to be things they might plausibly already have since they can't afford to wait for a supply mission.
- The ground troops are not robots. Let's just say that humanoid robots never caught on in this timeline (there's a story behind that, but this is the simplest way to put it).
Now, to @Dragongeek's question: why not just use laser arrays? Um... I don't know. From my perspective as an author, it's because that's not nearly as cool as orbital bombardment, but I'm going to need a more convincing reason. I'll probably put out a separate question about that. Just assume that hitting the envelopes with lasers from orbit is not an option.