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 01-21-2019, 07:10 AM   #31
ericthered
Hero of Democracy
 
ericthered's Avatar
 
Join Date: Mar 2012
Location: far from the ocean
Default Re: Orbital Lasers

This conversation moved fast.

In the other thread, I mentioned the options were limited to hiding targets, moving targets, and building targets. Plus threatening to shooting down landing craft and troops.

The biggest challenge for the alien craft is that of all artillery: target acquisition. How does it distinguish between a cargo truck and a truck-mounted SAM system? How does it know where the missile silos are? It can kill civilians indiscriminately, but is it willing to, and what does that ultimately accomplish? Once the enemy leader is on the run, its difficult to distinguish him from all the other running humans.

The only thing the humans can do is resist, but that isn't to say that resistance can't be effective.
__________________
Worlds Beyond Earth -- my blog
ericthered is offline   Reply With Quote
Old 01-21-2019, 09:05 AM   #32
kdtipa
 
kdtipa's Avatar
 
Join Date: Jun 2007
Location: Southern New Hampshire
Default Re: Orbital Lasers

Quote:
Originally Posted by AlexanderHowl View Post
... Such a spacecraft could engage forty surface targets every space turn from GSO...
People keep talking about GSO... but... that would be a fairly limiting thing for a space station using lasers to attack the ground. Its options for targets are limited to the side of the planet it's on. Maybe it can manage a continent?

You might be better off with Lagrange Points. That way the station would have visibility to any place that also has visibility to the moon (assuming you don't choose point #2 in their diagram in that wiki article).

Quote:
Originally Posted by AlexanderHowl View Post
How would a TL8 world deal with such a spacecraft?
I mentioned a completely non-technology based solution earlier in the thread. No one has responded. But getting someone or a few people on board a supply shuttle to sabotage the place sounds like a pretty great adventure seed to me.

Alternatively, is there stealth technology? Can humans secretly spend a bunch of resources on developing stealth tech that works against alien sensors? Maybe steal something more minor of alien sensor technology so they have something to test with? And then create something that can reach the alien ship with that technology? Get it up into space with what looks like a normal satellite placement, and then launch a mission from there? Or just a stealth missile?
kdtipa is offline   Reply With Quote
Old 01-21-2019, 09:23 AM   #33
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: Orbital Lasers

Quote:
Originally Posted by kdtipa View Post
People keep talking about GSO... but... that would be a fairly limiting thing for a space station using lasers to attack the ground. Its options for targets are limited to the side of the planet it's on. Maybe it can manage a continent?
From GSO one can cover about a third of the globe, though the edges of that area will have annoyingly steep angles of fire and vision. However, if you're not in a tearing hurry you can just adjust your orbit a bit and let the planet slowly rotate until you're over whatever you want to blast, and then adjust your orbit back to an exact 24-hours.
Quote:
You might be better off with Lagrange Points. That way the station would have visibility to any place that also has visibility to the moon (assuming you don't choose point #2 in their diagram in that wiki article).
That's a lot further away, outside the range of any of the beam weapons in Spaceships. Using Spaceships 3, that's inside the 1/2D range of a 100TJ+ Graser, X-Ray, or UV laser. However SS says that Grasers and X-ray lasers can't be used for orbit to ground attack through an atmosphere. Given that UT also sharply limits the range of UV lasers, they should probably also be so restricted. Thus the L-points are too far away to make useful positions from which to make beam weapon attacks on Eath's surface.

Sitting at the L-points also means that you are exchanging covering a limited area at all times for limited coverage times over the whole Earth. Neither is ideal, of course.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is online now   Reply With Quote
Old 01-21-2019, 10:40 AM   #34
kdtipa
 
kdtipa's Avatar
 
Join Date: Jun 2007
Location: Southern New Hampshire
Default Re: Orbital Lasers

Quote:
Originally Posted by Rupert View Post
...However, if you're not in a tearing hurry you can just adjust your orbit a bit and let the planet slowly rotate until you're over whatever you want to blast, and then adjust your orbit back to an exact 24-hours.
...
Sitting at the L-points also means that you are exchanging covering a limited area at all times for limited coverage times over the whole Earth. Neither is ideal, of course.
The space station has thrusters for maneuvering? I missed that detail.

Maybe there should be three or four stations each covering their own area...
kdtipa is offline   Reply With Quote
Old 01-21-2019, 10:52 AM   #35
ericthered
Hero of Democracy
 
ericthered's Avatar
 
Join Date: Mar 2012
Location: far from the ocean
Default Re: Orbital Lasers

Quote:
Originally Posted by kdtipa View Post
The space station has thrusters for maneuvering? I missed that detail.

Maybe there should be three or four stations each covering their own area...

The bombardment has been described as coming from a SM+15 hyper-drive capable ship with access to TL10^ technology, though we are discussing a subset of its abilities. I agree that if you want to cover the planet while orbiting, you want three or more locations. Though if you're only targeting one nation, a single ship is fine.
__________________
Worlds Beyond Earth -- my blog
ericthered is offline   Reply With Quote
Old 01-21-2019, 11:11 AM   #36
kdtipa
 
kdtipa's Avatar
 
Join Date: Jun 2007
Location: Southern New Hampshire
Default Re: Orbital Lasers

Quote:
Originally Posted by ericthered View Post
The bombardment has been described as coming from a SM+15 hyper-drive capable ship with access to TL10^ technology, though we are discussing a subset of its abilities. I agree that if you want to cover the planet while orbiting, you want three or more locations. Though if you're only targeting one nation, a single ship is fine.
Hyperdrive capable doesn't do it. But I suppose "ship" implies the ability to maneuver. I was working with my memory and impression... which is of an orbital station. I suppose if it's a ship... the kind of orbit you use can vary all you like.

Anyway... I still think humans finding a technological solution is less likely than a clever solution like boarding a supply shuttle and blowing it up from the inside.
kdtipa is offline   Reply With Quote
Old 01-21-2019, 11:27 AM   #37
ravenfish
 
Join Date: May 2007
Default Re: Orbital Lasers

Quote:
Originally Posted by kdtipa View Post
The space station has thrusters for maneuvering? I missed that detail.
A space station has some sort of minor thrusters almost by necessity. In low orbit, the outer traces of the atmosphere are thick enough that periodic burns are necessary to maintain velocity; they are needed to keep a precise position even when completely out of the atmosphere given the accumulation of small changes in orbital position from the complexities of earth's gravitational field, the force of solar radiation etc.

EDIT: In particular, a strict geostationary orbit (directly over the equator) is out of line with the orbit of the moon, so periodic burns are required to keep the moon's gravity from shifting the plane of orbit.
__________________
I predicted GURPS:Dungeon Fantasy several hours before it came out and all I got was this lousy sig.

Last edited by ravenfish; 01-21-2019 at 11:33 AM.
ravenfish is offline   Reply With Quote
Old 01-21-2019, 11:42 AM   #38
AlexanderHowl
 
Join Date: Feb 2016
Default Re: Orbital Lasers

A large enough spaceship can function as a mobile station. While a mobile station may seem less efficient than a static station, it has the advantage of being less vulnerable to ballistic attacks from a planetary surface and can always retreat. After all, the Death Star was a mobile station...though it was victim to commanders who did not seem to understand that mobile stations should retreat from attacks rather than heading towards them (dropping a squadron of TIE-fighters to engage the Rebel forces while the Death Star retreated would have been a much more logical reaction).
AlexanderHowl is offline   Reply With Quote
Old 01-21-2019, 01:55 PM   #39
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: Orbital Lasers

Quote:
Originally Posted by AlexanderHowl View Post
A large enough spaceship can function as a mobile station. While a mobile station may seem less efficient than a static station, it has the advantage of being less vulnerable to ballistic attacks from a planetary surface and can always retreat. After all, the Death Star was a mobile station...though it was victim to commanders who did not seem to understand that mobile stations should retreat from attacks rather than heading towards them (dropping a squadron of TIE-fighters to engage the Rebel forces while the Death Star retreated would have been a much more logical reaction).
Star Wars is an environment that works like WWII aero-naval warfare (though the Death Star commanders and designers thought the Death Star was big enough that they could act like it was WWI). Carriers don't retreat from aircraft - they send up their own aircraft, or rely on AA fire.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is online now   Reply With Quote
Old 01-21-2019, 02:11 PM   #40
AlexanderHowl
 
Join Date: Feb 2016
Default Re: Orbital Lasers

Honestly though, that only works when the secondary craft are much faster than the primary craft. When you can jump into hyperspace to avoid fighters, that makes it more ballistic submarine versus fighter jets. Ballistic submarines survive through stealth and by avoiding unnecessary combat, which is how the commanders of the Death Star should have treated it. It is not the combat abilities of ballistic submarines that are terrifying, it is the fact that they can pop up anywhere and use those combat abilities that is terrifying.

One of the problems with any large interstellar polity is that they have access to vast amounts of resources. The interstellar dust of a cubic light year alone masses more than forty Sol systems, and a polity that controlled a sphere 500 ly in radius (over one million star systems) has a volume of over 500 million cubic light-years, giving it ~20 billion Sol-masses of interstellar dust to work with. Even if they ignored the dust, they would like having enough debris in their star systems to allow them to support millions of spacecraft.
AlexanderHowl 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 04:28 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.