# Little help? Kind of stuck on a space battle strategy



## Dennis E. Taylor (Feb 4, 2015)

I'm kind of stuck on a plot point, and I could use some brainstorming suggestions. Here's the situation:

You've got a spaceship (the good guy) just arrived in a star system. An enemy ship (the bad guy) will be arriving within a short time-- weeks to months. The bad guy knows the good guy got there first, so total surprise is out. The good guy has some manufacturing capability, but doesn't know what raw materials are available yet. The bad guy has missiles. The good guy is unarmed at the moment.

I obviously want the good guy to win. I'll do it with a straight duke-em-up fight, but I'd prefer something tricky. I've got a couple of ideas, but they sound trite to me. I'd appreciate it if you could fire off (hah hah) any ideas that come to mind, either something you remember from books you've read, or anything that comes to mind.

I'm kind of blocked, here, and  hopefully this can loosen something up.


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## Droflet (Feb 4, 2015)

Hello Biz,
Hmmm, manufacturing capability, aye? Okay, how about they discover a vein of corbomite, a highly unstable element that goes off with an almighty bang. They could mine a particular area of their space and draw the enemy to them. They could also carry mines in their hold with proximity fuses that they drop into the path of the onrushing baddie. And, if they are a much larger vessel than the baddie they could, as a last measure, ram them. Just off the top of my head. Good luck.


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## thaddeus6th (Feb 4, 2015)

Well, you could have the bad guy hide behind a moon for sneaky reasons, only for the 'good' guy to then explode the said moon with a bomb embedded in its centre. Debris tears the bad guy to pieces.


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## Brian G Turner (Feb 4, 2015)

It sounds like you might need to do an "A-Team" - put together useful arms from garage equipment - which will show off the cleverness of your characters.


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## Ray McCarthy (Feb 4, 2015)

There is no air resistance in space (obviously), so pipes firing scrap steel, fed by explosive charge, compressed gas etc will be effective against missiles, which reveal position by their exhaust. If the bad guy is "tricked" into manoeuvring into a stream of matte painted scrap steel* fired forward previously with the good guys ship at full speed, it will tear bad guy's ship to pieces.

Even on Earth some defence systems fling a "wall" of shrapnel. Flinging "rocks" works very well in space.

(* or possibly ceramic scrap or flints as it doesn't show up on radar as well)


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## Vince W (Feb 4, 2015)

Ray McCarthy said:


> There is no air resistance in space (obviously), so pipes firing scrap steel, fed by explosive charge, compressed gas etc will be effective against missiles, which reveal position by their exhaust. If the bad guy is "tricked" into manoeuvring into a stream of matte painted scrap steel* fired forward previously with the good guys ship at full speed, it will tear bad guy's ship to pieces.
> 
> Even on Earth some defence systems fling a "wall" of shrapnel. Flinging "rocks" works very well in space.
> 
> (* or possibly ceramic scrap or flints as it doesn't show up on radar as well)



This was my first thought.

A variation might be to create some sort of _ad hoc_ railgun. Can only be used once and at fairly close range so the trick is to get the bad guy within range without getting destroyed in the process.


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## Mirannan (Feb 4, 2015)

How about a mass-driver firing bucketfuls of gravel? It would be possible to retrieve the buckets, which has two benefits; first less need to manufacture the buckets and second less detectability. A metal bucket would show up really well on radar, a cloud of pea-sized gravel almost not at all.


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## Vince W (Feb 4, 2015)

The wall of gravel would work just as well if you filled a forward hold full of gravel, accelerated to near c, and then decelerated letting the gravel continue on. Inertia does the rest. Even a small mass at that speed packs a massive punch. The ship becomes a shotgun.


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## Mirannan (Feb 5, 2015)

Vince W said:


> The wall of gravel would work just as well if you filled a forward hold full of gravel, accelerated to near c, and then decelerated letting the gravel continue on. Inertia does the rest. Even a small mass at that speed packs a massive punch. The ship becomes a shotgun.



Yup. In fact, the available options depend critically on the tech level in the scenario. And not just general tech level, but which particular technologies are well developed.

As an example of the latter, it's reasonably easy to imagine an alternate world of 2015 AD in which computers are still room-sized but humanity is running around all over the Solar System in Orion-drive spacecraft.

Your scenario of accelerating to large fractions of c and chucking out clouds of gravel (assuming the sides are of comparable tech level) also allows the possibility of relativistic strategic weapons - which make fixed installations, particularly those on planetary surfaces, incredibly vulnerable.


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## JunkMonkey (Feb 5, 2015)

The bucket of rocks idea was the first thing that came to my mind too.  If you want add added sneakiness why not slingshot the stuff round a convenient gravity well and hit the bad guy from the rear where he would be less likely to be looking for it?  - I am assuming interstellar craft will have some form of small rock collision avoidance system, but would craft going at such velocities be expecting stuff to be approaching from* behind *them at dangerous speeds - oh! or even better! from 'above' or 'below' the  plane of the ecliptic of your solar system as well.


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## Ray McCarthy (Feb 5, 2015)

With constant G high power Ion Drive + linear accelerator, who ever gets there first can leave all sorts of 0.1C to 0.4C gravel traps, often not in orbits, or outside plane of ecliptic. As the person releasing them knows were they all are and their vectors they can predict months later where to dodge and lead the persuer


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## Mirannan (Feb 5, 2015)

Ray McCarthy said:


> With constant G high power Ion Drive + linear accelerator, who ever gets there first can leave all sorts of 0.1C to 0.4C gravel traps, often not in orbits, or outside plane of ecliptic. As the person releasing them knows were they all are and their vectors they can predict months later where to dodge and lead the persuer



Errmm, no. Not at those speeds. Why? Simple. Even at the lower end of that range, using Sol system as a reference the rocks would be beyond the orbit of Neptune in a couple of days. (Neptune is about 5 light-hours out.)

Saying again that tech level is crucial - really powerful laser arrays, perhaps based on inner planets with lots of sun (Mercury in Sol system, as an example) would be useful. Even if they aren't powerful enough to damage the incoming ships, sensors are a lot less tough.

The laser arrays would have non-weapon uses, too. Laser-boosted photon sails have been seriously discussed as transport...


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## AnyaKimlin (Feb 5, 2015)

As we are going A-Team what about a cabbage in the exhaust pipe?


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## Ray McCarthy (Feb 5, 2015)

Mirannan said:


> Errmm, no. Not at those speeds. Why? Simple. Even at the lower end of that range, using Sol system as a reference the rocks would be beyond the orbit of Neptune in a couple of days.


Depends where you start them from


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## JunkMonkey (Feb 5, 2015)

I thought the point of littering the place with piles of dangerous pea gravel from unexpected directions - presumably the incoming ship will have charts that have every known hazard to shipping marked - was that the incoming ship would smack into them at high percentage of light speed velocities so the rocks could be travelling pretty slowly just in usually very empty places,


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## Ray McCarthy (Feb 5, 2015)

Yes, that can work too.


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## Dennis E. Taylor (Feb 5, 2015)

Thanks for all the input. I've got a problem with ballistic booby traps in that one piece of available technology can detect masses up to a light hour away. Unfortunately that's essential enough to other plot points so that I can't get rid of it.

Instead, I've strapped a small reactor, an oversized drive, and an AI pilot to a five-hundred-pound ball of iron. A half-dozen of them can catch and hole a ship pretty effectively.


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## Droflet (Feb 6, 2015)

Nice.


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## Mirannan (Feb 6, 2015)

Ray McCarthy said:


> Depends where you start them from



Well, sure - but the stuff would cross Sol system from one side of Neptune's orbit to the other in 4 days. You would have to replenish the supply rather often.

There is, of course, the small point that some advanced alien race might come looking for whoever it is that is littering space with relativistic gravel. 

Bizmuth - Can your detector find masses of a couple of grams at interplanetary distances? Impressive.


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## Dennis E. Taylor (Feb 6, 2015)

Mirannan said:


> Bizmuth - Can your detector find masses of a couple of grams at interplanetary distances? Impressive.



I'll ask Dr Demento.  Seriously, I haven't been too specific yet about the limits of the technology. But it seems to me that you'd have to send off a _lot_ of gravel over a wide swath to have a chance of hitting the enemy, especially since you wouldn't know his exact approach path at launch time. A large cloud of debris would probably be detectable. That's the whole purpose of SUDDAR, right?


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## jastius (Feb 8, 2015)

Couldn't he shift things so that there are asteroids everywhere? Then he could hide behind them constantly using them as cover.
The only detectable mass signatures would be the booby traps.
That way instead of worrying about driving the stuff into the other vessel, you get the other vessel to come close enough to the stuff, that a mine set to detect a certain mass of metallic signature, which also is the composition of mr baddies hull, will go boom.


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