Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 01-23-2019, 05:20 AM   #61
AlexanderHowl
 
Join Date: Feb 2016
Default Re: Orbital Lasers

From my understanding, it is the rarity of tritium, an essential component of thermonuclear weapons, that makes decoys worthwhile. When you require 10 grams of tritium for the thermonuclear reaction in a three stage bomb, you only produce 20 kilograms per year, and half of it decays every 12.5 years, you have a rather sharp limit on how many thermonuclear warheads you can support. You either turn to pure fission and accept that you will have larger mass warheads with more fallout or you pack the MIRVs with decoys so that your real warheads can survive antimissile fire.
AlexanderHowl is offline   Reply With Quote
Old 01-23-2019, 05:35 AM   #62
Daigoro
 
Daigoro's Avatar
 
Join Date: Dec 2006
Location: Meifumado
Default Re: Orbital Lasers

With the head-on approach vector, perhaps the decoys could be just thin disks with the same 2D profile as the warheads. Spin them so they remain horizontal.
__________________
Collaborative Settings:
Cyberpunk: Duopoly Nation
Space Opera: Behind the King's Eclipse
And heaps of forum collabs, 30+ and counting!
Daigoro is offline   Reply With Quote
Old 01-23-2019, 06:13 AM   #63
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: Orbital Lasers

Quote:
Originally Posted by AlexanderHowl View Post
From my understanding, it is the rarity of tritium, an essential component of thermonuclear weapons, that makes decoys worthwhile. When you require 10 grams of tritium for the thermonuclear reaction in a three stage bomb, you only produce 20 kilograms per year, and half of it decays every 12.5 years, you have a rather sharp limit on how many thermonuclear warheads you can support. You either turn to pure fission and accept that you will have larger mass warheads with more fallout or you pack the MIRVs with decoys so that your real warheads can survive antimissile fire.
When you look at the number of warheads in existence during the Cold War, or even today, that's not really the problem. There were often more warheads than missiles to carry them, even allowing for the ones intended to give bomber pilots some vague relevancy, Soviet anti-carrier weapons, and the like.

Note that tritium was/is common and affordable enough that it was and is used in night vision devices, and as the energy source of luminous displays and such.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is offline   Reply With Quote
Old 01-23-2019, 08:34 AM   #64
Anaraxes
 
Join Date: Sep 2007
Default Re: Orbital Lasers

Quote:
Originally Posted by Michele View Post
In fact, the whole basic assumption is that saturation will work: i.e. that those laser batteries cannot fire continuously because they will overheat. if they have no such problem, then no attack will ge through.
That's where the "tap the decoy" tactic comes in. You can use low-power shots for that, possibly from targeting lasers that are different from your high-power weapons. They presumably can cycle faster and have much less of a heat problem.

Certainly, we can just assume that saturation works, so that's the way for the PCs to go. The valiant humans need a way to defeat the evil alien oppressors, after all :) Assuming the conclusion is the fasted way to end the speculation and get on with the game. (Well, for the OP anyway. The rest of us don't get to play, so we'll be left behind on the forum to keep on speculating to no end...)

My point is merely that it's not as simple as saying "the attacker would just use decoys" as a clear IWIN strategy to argue that no sensible alien oppressors would ever build an orbital laser ship

(If saturation is such an obvious and easy tactic, why did the aliens build such an easily defeasible terror machine in the first place? They've conquered their way across the galaxy, but humans are the first to come up with the obvious and easy idea? No one ever thought of it at all, because humans are uniquely ingenious when it comes to war? Earth is the first place they've had a chance to try their new toy, so naturally it has some teething problems that have yet to be worked out? Or is it that decoys must not be so easy and obvious after all? Assuming saturation works calls for a little more world-building thought, or else increasing the level of WSOD so the table agrees not to poke that assumption so hard that it breaks.)
Anaraxes is offline   Reply With Quote
Old 01-23-2019, 09:28 AM   #65
malloyd
 
Join Date: Jun 2006
Default Re: Orbital Lasers

Quote:
Originally Posted by Anaraxes View Post
Certainly, we can just assume that saturation works, so that's the way for the PCs to go. The valiant humans need a way to defeat the evil alien oppressors, after all :)
Of course while it's a reasonable enough solution in a strategy game, it's a boring one for an RPG. The PCs aren't actually *involved* in this solution, somebody who has a bunch of nukes, decoys and ICBMs does all the work.

A serious centralized military threat is not the best choice of plot for an RPG - a background story against which the PCs are doing something else sure, and just maybe it can be the final boss, but the central plot focus needs to be something that can be fragmented into staged goals.
__________________
--
MA Lloyd
malloyd is offline   Reply With Quote
Old 01-23-2019, 10:31 AM   #66
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Orbital Lasers

Quote:
Originally Posted by malloyd View Post
Of course while it's a reasonable enough solution in a strategy game, it's a boring one for an RPG. The PCs aren't actually *involved* in this solution, somebody who has a bunch of nukes, decoys and ICBMs does all the work.
The PC solution is that you smuggle a bunch of PCs up in one of the shuttles the aliens are using to transport stuff between the ground and their spaceship, and once on board the alien ship the PCs proceed to wreak havoc.

The more plausible version of that replaces the PCs with a bomb.
__________________
My GURPS site and Blog.
Anthony is online now   Reply With Quote
Old 01-23-2019, 10:41 AM   #67
Michele
 
Join Date: Aug 2004
Location: Udine, Italy
Default Re: Orbital Lasers

Quote:
Originally Posted by malloyd View Post
Of course while it's a reasonable enough solution in a strategy game, it's a boring one for an RPG. The PCs aren't actually *involved* in this solution, somebody who has a bunch of nukes, decoys and ICBMs does all the work.

A serious centralized military threat is not the best choice of plot for an RPG - a background story against which the PCs are doing something else sure, and just maybe it can be the final boss, but the central plot focus needs to be something that can be fragmented into staged goals.
The strategy works, but the aliens manage to shoot at and destroy most of the warheads and kinetic rounds. They also try to maneuver their way out of the kill area, but don't entirely succeed.
The battle station gets hosed by the radiation (and instant heat on its armor) of several near-miss nuclear explosions, and also pummelled by a dozen small-sized kinetic projectiles that punch many holes in it.
It is no longer operational, or a threat. It's a wreck. But it still is a very big thing, an irradiated thing (apart from our nukes, there are those reactors that will have been damaged), possibly with some aliens still barely surviving aboard it... on a quickly decaying orbit because of those failed evasive maneuvers.

Do we still have some vehicle that can bring up there a team of very brave operators? They should place demolition charges on the main structure to make sure the thing is destroyed in fragments so small they'll burn on entry. And before that, they could try and gather useful intelligence, because a second station might be coming. And they should do so quickly, because it's nearly a suicidal mission due to the radiations. And if they can bring back a live alien, so much the better.
__________________
Michele Armellini
GURPS Locations: St. George's Cathedral
Michele is offline   Reply With Quote
Old 01-23-2019, 10:50 AM   #68
AlexanderHowl
 
Join Date: Feb 2016
Default Re: Orbital Lasers

How are you doing all of this to a spacecraft in GSO? Try designing a TL8 spaceship using Spaceships that can achieve 8.5 mps (minimum realistic delta-v for surface to GSO) and you will see what I mean.
AlexanderHowl is offline   Reply With Quote
Old 01-23-2019, 10:53 AM   #69
Michele
 
Join Date: Aug 2004
Location: Udine, Italy
Default Re: Orbital Lasers

Quote:
Originally Posted by Anaraxes View Post
If saturation is such an obvious and easy tactic, why did the aliens build such an easily defeasible terror machine in the first place?
The ultimate war-making vehicles of WWII were the battleship and the aircraft carrier. Nothing larger was built. Small submarines could and did still damage many of them, and sink a few. The submarine threat was of course obvious.

One could object that those were weapons systems of the same TL.
Punji traps were low-tech devices of admirable simplicity. The US soldiers in Vietnam had higher tech than that, were entirely aware of the threat, and yet punji traps remained effective.
__________________
Michele Armellini
GURPS Locations: St. George's Cathedral
Michele is offline   Reply With Quote
Old 01-23-2019, 10:53 AM   #70
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: Orbital Lasers

My conclusion is that a TL10, SM+15 spaceship such as this, in a GSO orbit, is a plot device.

Something to be shot at, or otherwise messed with, will be smaller, and in a lower orbit.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 10:37 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.