Limiting size of Jump capable ships

[Meanderer]

Except by this time, it would be easier to tailor a virus that could kill not just planets, but whole subsectors with much less effort than a bunch of kinetic kill weapons. However, this runs against reality, such as today, where genocide, and genocidal weapons of mass destruction, simply aren't used. Functional NBC warfare was developed during WW2, but for the most part, except for cases like http://en.wikipedia.org/wiki/Unit_731 or the bombing of Nagasaki and Hiroshima, it never becomes standard procedure.

Yes. Biological warfare is also a threat. Biological weapons have problems of their own. You can get a virus that quickly kills virtually everyone who contracts it, a super-Ebola, but if it kills its victims before they can transmit it to others then it may not spread well. Flu viruses are so persistent because they don't kill everyone who gets them and they inflict symptoms (coughing and sneezing) that spread the virus. Develop something that can stay airborne for long periods of time, not killed as quickly by ultraviolet light, long latency period so people infected will move around and infect others before they get sick and die - can present a problem if someone picks up the virus and carries it by starship to your world.

The biggest problem faced in using such WMDs is that the truly massive/effective attacks require the resources of an interstellar government or mega-corporation. It isn't easy to hide who was responsible and executing such an attack may invite retaliation by the victim government or by your neighbors who decide they must pre-emptively strike you before you can do the same to them.

Civilian leadership generally seeks to avoid wars because war is messy. You look at our history with major powers possessing nuclear and other WMDs. The difference between Japan 1945 and Vietnam 1965 is in 1945 only one nation had such weapons. Later, when you have to be concerned about whether someone else will use their weapons, you start getting more careful.

Wasn't the motto of the USA Strategic Air Command "Our Profession is Peace". Possessing a massive force of bombers designed to deliver nuclear bombs but their purpose is avoiding their use? Yes. The point was to present such an overwhelming threat to anyone who attacks you that no one dares to let a war go nuclear.

So the Imperial Navy demonstrates some massive kinetic missiles against some moon designated as a test-firing range when they know that foreign agents are watching covertly - because they aren't intending to use them in a sneak attack but instead want the Zhodani to be cautious about provoking the use of these weapons in retaliation.

 

[sideranautae]

The numbers I crunched show that projectiles going 5,000 km/second will hit with the force of nuclear weapons. A velocity of 5,000 km/s can be achieved from a stationary position in about 1 day at 6G (not many days).

Yes? As I correctly wrote earlier. SUPER easy to deflect. (a particle beam hitting the object for a couple seconds diverts. So, you have spent the time and money for a ship to deliver nothing to the planet surface. What is then the point? Please explain.

 

[dragoner]

So the Imperial Navy demonstrates some massive kinetic missiles against some moon designated as a test-firing range when they know that foreign agents are watching covertly - because they aren't intending to use them in a sneak attack but instead want the Zhodani to be cautious about provoking the use of these weapons in retaliation.

By this point, IMO, all these world destroying weapons have been around for a long time, the Zhodani have them, everyone does. While MAD might be a reason, more likely it is ROE, things that are just not done, similar to today, or in recent wars, where the forces are asymmetrical. The list of terrible things one could do, is near endless, but which are not done because they are considered morally reprehensible. It could be chalked up to Sun Tzu's maxim of "keeping the moral authority" or just the innate goodness of sentient beings (sophonts); either way, the effect is the same. You are totally correct in the power of such weapons to do the damage that they would do.

 

[Meanderer]

In response to sideranautae

So, you have a particle accelerator that causes fighter craft that you hit with it to accelerate sideways at 50G acceleration? I guess if you don't destroy the craft outright the pilot will be killed by the G force alone. Um, but particle accelerators don't do that. You hit and energy goes into the object. Some of it kinetic. A lot of it as heat. Some of it lost.

But consider how much acceleration you are putting into the object by firing at it? Can you hit a chunk of metal and by vaporizing a small part of it turn it into a rocket with a 50G Thrust?

Basic math, by the way. This amazing thrust over two seconds means that the kinetic torpedo now has a lateral velocity of 1km/s as it flies towards the planet. Each second it goes another km off its course. This is constant because you have imparted acceleration into the object - it maintains this deflection momentum drifting further of course every second. But vectors are added - not replaced. So you plot its course as a triangle. Each second = 1 km sideways. Each second = 5,000 km straight ahead. For all intensive purposes it is still heading in the same direction at pretty much the same speed. (deflection can work in any direction, speeding it up or slowing it down can have the same effect of making it miss because the planet is orbiting the star - intercepting the planet's orbit too early or too late means the planet isn't there yet or has already passed. But it takes a lot of energy to get such an object up to speed (thrust applied over a period of a day or days) and it isn't easy to alter that course very much over just a few seconds. You can get deflection going but it has to be far enough out to make that deflection add up to missing the target.

If it is aimed at a planet 8,000 km in diameter (size 5?) it will have to go off course by around 4,000 km in order to miss its target. So if you can apply this 50G acceleration over two seconds then it will miss, if you do this while it is 20 million km or more away from its target. (Assuming they are aiming at the center of the planet, but why wouldn't they?). BTW, getting a ship out to that interception point to deflect the kinetic weapon would take 7 hours at 6G.

We don't see particle accelerators and lasers pushing enemy vessels around because mostly they just burn a very small hole into the object and heat the object up (melting away armour and damaging equipment/puncturing hulls, etc.) When your target is just a solid object it isn't that easy. You heat it up, melt it, and what? It doesn't have moving parts, electronics, crew. It is just a chunk of metal. And if 50 tons of molten metal hits the atmosphere, or 50 tons of gaseous metal for that matter, it will still deliver its kinetic energy into the planet's atmosphere and surface.

I posted some links earlier on kinetic hits to Earth by meteors. One hit Siberia and caused a measurable change in air pressure over England, leveling thousands of square km of forest. Look up Tunguska. And keep in mind that the Tunguska object was very slow moving compared to the weapon I described like comparing walking speed to the speed of a fighter jet on afterburners) and was therefore unable to penetrate the atmosphere before it exploded due to differences in air pressure. At 5,000 km/s there wouldn't be enough atmosphere to slow the object down.

As you wrote - super easy to deflect. As you didn't consider - not so super easy to get out far enough to deflect the object on-time.

Let's crunch some numbers on a more reasonable interception. Let's assume you can deliver 2G acceleration to the object you hit with the particle accelerator. And because effective weapon range is around 50,000 km let's assume you can fire continuously for 10 seconds. I think I am being generous with the 2G acceleration. But this will give you a deflection of 1km while you are firing and a further 200 m/s after that. To get a 4,000 km deflection to miss the planet - you have to do this 19,995 seconds out from impact. That's 100 million km away.

We can crunch these numbers all day. If you intercept the weapon 4 million km away from impact you would need an energy weapon capable of deflecting it with a 500 G force. What kind of particle accelerator do you have that is capable of deflecting kinetic torpedoes like that and how many do you have in position?

And if the enemy knows you have some powerful particle accelerators you can use, wouldn't they just split those 50 ton torpedoes into ten 5 ton torpedoes (making a much smaller target and making your deflection of a few of them trivial.

 

[Meanderer]

Dragoner wrote

By this point, IMO, all these world destroying weapons have been around for a long time, the Zhodani have them, everyone does. While MAD might be a reason, more likely it is ROE, things that are just not done, similar to today, or in recent wars, where the forces are asymmetrical. The list of terrible things one could do, is near endless, but which are not done because they are considered morally reprehensible. It could be chalked up to Sun Tzu's maxim of "keeping the moral authority" or just the innate goodness of sentient beings (sophonts); either way, the effect is the same. You are totally correct in the power of such weapons to do the damage that they would do.

Precisely. Do the political leadership want to be associated with something like this? Does the Admiral in command want to go down in history as a mass murderer of tens of billions? Would the captain(s) of the ship(s) be willing to go along with it?

 

[Nobby-W]

As the next part of my rules rewrite is to decide on ship sizes. I think I'll limit Jump capable ships to 10,000 tons. M-drives won't have that limitation.

I did an IMTU-ism for Zuchai crystals to limit jump drive sizes that may be pertinent to your setting. IMTU the Zuchai crystal was a single, large, flawless high-temp superconductor (or some similar trope) that the drive was based around. A small one for a Jump drive-A might weigh about half a ton; a large one might be the size of a railway locomotive.

This means that the manufacture of jump drives is limited by your ability to grow large, flawless crystals that are quite difficult to grow (think maintaining Zero-G and very constant, very high temperatures for months or years on end). Thus, big ones are (a) very expensive and (b) very difficult and time-consuming to grow, needing high technology and a very large investment in space-based plant in the outer system, far away from disturbances.

This also explains why people might care about naturally-occurring Zuchai crystals, as the cost of growing large synthetic ones makes it worth finding rare deposits of naturally occurring ones of sufficient quality to make into a jump drive. It also gives a good reason to limit the rate at which very large jump drives (and thus jump capable ships) can be manufactured.

As an aside, in early versions of Traveller (i.e. CT Book 5) I found the balance of the starship combat did not work well for smaller ships of the type a party might use. At one point I had a bastardised version of High Guard/Book 2 starship combat designed to balance better for ships in the 100-1000 ton range. I re-jigged weapons like low-ish factor spinal mounts at higher tech levels to be small enough to fit into hulls in the 5,000-10,000 ton range, made larger turrets with 2-3EP weapons and a few other mods (like using Book-2 program based DMs rather than computer size for to-hit rolls).

Similar mods to re-balance spinal, bay and other weapons in later versions might allow you to have ships where the naval craft are not so far removed from the realms that adventurers live in.