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Hi! I'm currently building a hard sci-fi world and I was wondering about the idea of war. Because space is huge - really huge, and most ships probably won't interact with each other for years or centuries. But if two space ships or fleets were to meet on a new stellar system and declare war to each other, what could this look like? What weapons could they use?

Have you ever tackled the subject in one of your worlds? Or do you know a piece of media which did this?

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[-] Blaster_M@lemmy.world 4 points 5 months ago* (last edited 5 months ago)

1: projectrho

2: assuming no handwavium drives, engagement range is always the outer edge of the plane between the targeting system's minimum precision and maximum traverse rate, shot travel time and ability versus the opponent's ability to react and evade said shot.

3: they've been carrying beef for centuries? Their grandkids will be the ones to do the fighting.

Lasers can reach the furthest with minimal ability to anticipate an attack (lasers can be seen preparing to fire, like aiming, dust covers retracting, etc.), but kinetic weapons bring more pain if you can get close enough. Getting close is difficult if there is no FTL, since you and your bullets / missiles can be spotted and plotted well in advance of your arrival.

[-] DScratch@sh.itjust.works 3 points 5 months ago

Detecting and intercepting kinetic weapons could be very very difficult. You shape them like stealth bombers, paint them in a radar absorbing coating and launch them at Mach 10 or so. Especially since you have nearly unlimited range to fire from and gravity assists to achieve funky angles of attack. A projectile of depleted uranium with a titanium weave penetrating core would be there with nuclear weapons for destructive power and harder to stop.

In a universe where the Rods From God are an everyday threat, planetside military bases would be easy pickings, so spacefaring craft with erratic trajectories would be preferable. (You could have a plot arc about someone stealing the navigation software that adds randomness to a ship’s course to avoid long-range ballistics)

[-] athairmor@lemmy.world 2 points 5 months ago

What happens if you to your ship if you fire something at Mach 10?

If you can see your opponents ship, can you determine, by it’s change in velocity, the mass fired and direction? If you’re far enough away do you have time to just move out of the way?

[-] absurde@slrpnk.net 1 points 5 months ago

Would that render kinetic weapons pretty much impracticable for a spaceship-to-spaceship war?

[-] Blaster_M@lemmy.world 1 points 5 months ago* (last edited 4 months ago)

And that's why lasers are the king of range. However, they can be a nuisance at a distance more than a threat, as they are easier to defeat with the right armor setup.

That said, the big thing with kinetics is your effective range shrinks substantially, but it is much harder to defend against reliably. The way to use kinetics is get close, take advantage of enemy weakspots.

[-] DScratch@sh.itjust.works 1 points 5 months ago* (last edited 5 months ago)

If kinetics are out of the picture, lasers are completely countered by mirrors.

Plus the intensity falloff is significant, especially over the distances space travel allows.

[-] Zeusz13@lemmy.world 1 points 5 months ago

I'd recommend watching the videos of Spacedock, who have a series on the topic.

I'd also suggest giving The Expanse a read or watch

[-] absurde@slrpnk.net 1 points 5 months ago

Didn't know that one, thanks for the recommendation!

this post was submitted on 15 Sep 2025
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