The ultimate weapon

[Carlobrand]

The elephant in the living room: no maximum speed.

You may recall A Dagger at Efate, a story of a ship set to crash into an Imperial military base. That was Artan's work - he never was fully committed to the cause, never willing to make the big sacrifices. My plan was better - and now, with our forces in defeat on Efate, it is time I put it in operation.

I intend to send a clear message to the Duke and his nobles. I intend to take a simple scout/courier and jump into Regina system, a bit under 300 million miles from the planet. I have the planet's orbital information in my ship's computer. I intend to have the computer plot an intercept course for the planet, one that will have the ducal palace in the right position at about the time I arrive at the planet - after accelerating at 2g for two days.

I know I'm not likely to hit the palace, but I should be able to hit within a couple hundred kilometers of it. I'll be doing 3456 kps by that point. It will be 2 and a half minutes between the time the detection grid picks me up and the time I make impact. Perhaps they can bring their defenses to bear in that time, perhaps not, but they can not stop a falling mass from falling. My little ship, or its riddled hulk - it matters not which - will impact with the force of 10 million terajoules: 2.5 gigatons. Perhaps giving them a new volcano and altering the world's UPP code for a year or so will let them know we will not be silenced.

Stop me if you can.

 

[Omnivore]

Even worse, specially designed relativistic bombardment vehicles (small craft). Launch from a few AU out, impossible to stop. Planetary kill on the cheap.

 

[Rigel Stardin]

I'm not sure what effect 18, 1 ton ceramic spheres hitting a planet at termial velocity would be? But my brother and I design such a weapon, we called it: Dragonslayer. He also came up with the idea of firing ceramic coated penatrator darts out of gatling gun from orbit: we called that, Black Rain.

 

[warwizard]

It would need to have the defenses able to convert the intruder into vapor or lots of 1 gram or less sized little bits, the atmosphere would then be sufficient to stop the damage.
How about hitting you with a 20g 1mt missile with a 500 Mega Ton contact nuke, 30,000 km from the planet, planet saved! Umm, guys sorry about your electrical power grid.

 

[warwizard]

Rigel, the scout ship is 1400 metric tons, and terminal velocity is really really slow: density 1.0 object in standard atmosphere, standard gravity... about 90 meters per second. your ceramic assume density 8, perhaps 8 times the velocity, or 720 m/s... .72km/s vs 3456km/s 1 mt vs 1400 mt. You're low by 7 orders of magnitude, 6 if we count that you have 18 shots.

 

[Omnivore]

Just playing around with the numbers and a quick HG design:
Splatter class Relativistic Bombardment Vehicle
ZZ-0405501-000000-00000-0 MCr 59.420 99 Tons TL10
9.9 DT fuel (2 months). 59.39 DT Cargo
0 Crew, pre-programmed flightpath only.

Launched from around 3.9K AU distance and accelerating constantly at 5G for 56 days, the Splatter class delivers 1247.4 metric tons at greater than 75% light speed. Ideal usage would jettison most of the cargo while inbound so that it would impact the target one half a planetary rotation period after vehicle impact.

Really you'd want the cargo to spread out, and the main vehicle to self-destruct, in such a manner that the impacting mass would be spread over the entire planetary surface. The result would strip all atmosphere off the target planet, vaporize any bodies of liquid, strip the surface down to the mantle, and kill off all life down to and including the bacterial level. Not shabby for less than 60MCr eh?

 

[McPerth]

Just playing around with the numbers and a quick HG design:
Splatter class Relativistic Bombardment Vehicle
ZZ-0405501-000000-00000-0 MCr 59.420 99 Tons TL10
9.9 DT fuel (2 months). 59.39 DT Cargo
0 Crew, pre-programmed flightpath only.

Launched from around 3.9K AU distance and accelerating constantly at 5G for 56 days, the Splatter class delivers 1247.4 metric tons at greater than 75% light speed. Ideal usage would jettison most of the cargo while inbound so that it would impact the target one half a planetary rotation period after vehicle impact.

Really you'd want the cargo to spread out, and the main vehicle to self-destruct, in such a manner that the impacting mass would be spread over the entire planetary surface. The result would strip all atmosphere off the target planet, vaporize any bodies of liquid, strip the surface down to the mantle, and kill off all life down to and including the bacterial level. Not shabby for less than 60MCr eh?

Is this price por single building or for mass building? At this price I'll send them in 'squadrons' just to make it sure to overload the defenses and to kill everything that can be killed in the planet.

 

[Omnivore]

Price for single, but I didn't include the robotic pilot (if one is required??). I think the discount price for volume was around 45MCr.

Worst part is, if you detect them at 2 light seconds, you only have 0.5 seconds before impact and no idea what (if any) course changes may have occurred. If you're going to use squadrons, probably 10DT versions would be plenty. Unless, of course, you want to turn the target into an asteroid belt... hmm mining technique for corrosive atmospheres?

 

[travlar]

For the most part, they'd be really easy to detect, particularly on a high population planet, that will almost certainly have sensor satellites away from the planet, extending their range of detection. What's really dangerous, though, is the ability to keep your momentum through jump. Get up to near lightspeed, jump to target, and, if you don't miss due to temporal inaccuracy, they won't have time to react, unless gravity travels faster than the speed of light, in which case densitometers might be enough.

But if you can see the ship coming, fire a missile at it, hit it in the front, and the relative speed would, I think, pretty much disintegrate the ship.

In general, though, empires and such won't use such tactics, and would help their enemies take out someone who did, even, because of the threat of retaliation. No one wants a war that leaves hundreds of planets uninhabitable, and therefore so much less useful, not to mention killing of billions of potential taxpayers, should you manage to take them over.

 

[mike wightman]

Disintegrating the ship won't help.

A 100t ball of plasma hitting a planet at 0.75c is still going to dump an awful lot of energy into the atmosphere of the planet

 

[Otto Harkaman]

I agree with Travlar that perhaps they only thing protecting a planet from destruction is a common consensus that to do so is beyond diabolical.

Would there be anyway of protecting a planet? Maybe a device that manipulates the planet's magnetic/gravity field so that objects can be repelled away, something that is perhaps beyond TL15? Would the cost of defense prove prohibitive?

Go ask the Darrians

 

[far-trader]

Well for one I don't think there's anything in Traveller to suggest that maneuver drives are capable of anything approaching significantly fractional-c velocities. In fact it's strongly suggested by the background that they top out at a velocity of 6G x 3.5 days. Because if you can't get there in a week or so (half acceleration and half deceleration) then you jump.

Personally I also feel the whole vector preservation through jump later addition is bogus on several levels and that, again supported by the way the game plays, jumping will zero your velocity relative to the destination. So no building up a big vector and jumping in with it to surprise your target.

Besides, in the setting history this scenario has happened... never iirc. There must be a reason or reasons for that. Physics, society, or something else is enough to mean it doesn't happen. Since society is a weak control I'm more of a mind that there are solid physics behind it being practically impossible.

 

[Omnivore]

I agree with Travlar that perhaps they only thing protecting a planet from destruction is a common consensus that to do so is beyond diabolical.

Considering that there would be zero forensic evidence, if there's more than one possible enemy it'd be impossible to know who launched the attack. Also relativistic bombardment would be very effective against 'legitimate' targets such as naval yards and other very large orbital/deep-space installations with no maneuvering capability.

Would there be anyway of protecting a planet?

The attack consists of hundreds of chunks of mass at > 70% light speed, given the OTU there's no way to detect and intercept - especially if the 'bomblets' have any maneuverability. With only about a quarter second window of opportunity against a target that is > 200,000,000 meters from where you see it - even lightspeed weapons can't hit.

At some tech level, perhaps you could create a planetary sized gravitational barrier of some sort. At TL15 *maybe* you could theoretically at least put enough satellites in orbit to give some sort of overlapping black globe shield - horrendous cost though.

There is one effective defense - don't colonize planets - colonize space. Especially if the habitats are somewhat maneuverable (even at a low thrust) so their exact positions aren't predictable.

Outside of that... you need longer detection ranges that Traveller supposes along with freespace ftl such as stutterwarp or 'Trek type warp.

[EDIT]
I have to agree with far-trader, for the OTU to hold, the physics of Traveller maneuver drives must prevent high fractional c speeds.
[/EDIT]

 

[far-trader]

The attack consists of hundreds of chunks of mass at > 70% light speed, given the OTU there's no way to detect and intercept

So, you chose to ignore the reality of physics that demands increasing the energy needed to accelerate to significant fractional-c velocities but accept the Traveller detection ranges as the best available when even current technology is demonstrably far superior?



Traveller detection ranges are for the gaming of combat to be interesting, an element of hide and seek in space that in reality is simply false.

Traveller maneuver drives were never intended as interstellar drives, and are even limited in interplanetary travel. You have jump drives for any trip that would take longer than about a week at best speed.

EDIT: roger that PS edit while I was typing here omnivore, guess I didn't need to add the reply above

 

[McPerth]

I agree that probably maneuver drives lose efficiency as speed raises, and it's left out of the rules because it was considered obvious (rules writers should never do that, though), so, while a very interesting scenario to especulate with, I'll never allow something like this should I be the referee.

Besides, in the setting history this scenario has happened... never iirc. There must be a reason or reasons for that. Physics, society, or something else is enough to mean it doesn't happen. Since society is a weak control I'm more of a mind that there are solid physics behind it being practically impossible.

I think to remember having read somewhere (I don't remember where, less so if it was canon) the ancients did something similar. Anyway ancients were TL 21+ and did not care about public opinion...

 

[Omnivore]

So, you chose to ignore the reality of physics that demands increasing the energy needed to accelerate to significant fractional-c velocities but accept the Traveller detection ranges as the best available when even current technology is demonstrably far superior?

Not to argue Just to correct something there - from the viewpoint of the accelerating craft it does not require increasing energy to maintain constant acceleration. Space_travel_using_constant_acceleration#A_Half_Myth:_It_gets_harder_to_push_a_ship_faster_as_it_gets_closer_to_the_speed_of_light

Traveller detection ranges and capabilities bear no connection or resemblance to real world technology. Detection ranges should be in light months rather than light seconds for any appreciable temperature. But then, Traveller largely ignores temperature or the need for spacecraft to radiate heat. For the OTU to hold, the magical maneuver drive field must somehow prevent infrared spectrum output and pump the heat of the operating spacecraft to somewhere unobservable from any angle.

However, even if real world physics were to be used for detection, the impossibility of defense against relativistic bombardment still holds unless you have some sort of free space ftl capability. At a fractional c speed difference between observers the possible position of intercept encompasses far too large a volume.

A good discussion of relativistic weapons is found in the book The Killing Star by Charles Pelligrino also Atomic Rocket's Relativistic Weapons.

To be fair, relativistic weapons are hard science fiction and Traveller is soft science fiction - hard to mix the two without running into all sorts of problems.

 

[mike wightman]

There are canon examples of ships achieving near c velocities.

The STL ships that ESA launched and colonised the Islands Cluster achieved 0.6c IIRC - I'll go check TCS in a bit.

In the Imperium and Dark Nebula boardgames ships are limited to jumping between stars, but they can cross empty hexes by spending a year or so at high near c velocities.

Then there are the STL colony ships that Earth sent to Spica, Hinterworlds and possibly the Old Expanses...

 

[Carlobrand]

It would need to have the defenses able to convert the intruder into vapor or lots of 1 gram or less sized little bits, the atmosphere would then be sufficient to stop the damage.
How about hitting you with a 20g 1mt missile with a 500 Mega Ton contact nuke, 30,000 km from the planet, planet saved! Umm, guys sorry about your electrical power grid.

Someone in an article on meteors pointed out that converting something to a lot of tiny bits doesn't necessarily save you from doom. The bits hit the atmosphere and transfer their energy to that. Enough bits and you've cooked the environment in that area.

So, let's say you've managed to react quickly enough and sent out a warhead big enough to vaporize the target - the planetary defenses are automated against uber-fast targets or some such. Now the ship's an expanding vapor cloud about ten seconds from impacting your atmosphere at 3000+ kilometers per second - i.e. with 10 million terajoules of energy, plus a bit for what you've just added, minus a chunk for whatever decelerative effect being turned into an expanding gas cloud contributes to the overall mass. I don't remotely have the physics to calculate that one, but my rough guess is 500 megatons verses 2.5 gigatons ten seconds from impact still leaves a lot of energy to add to the atmosphere.

Would it be localized? Would it be generalized? How fast would that cloud expand in the seconds before impact?

What happens when, say, a square kilometer of the upper atmosphere accepts 5 to 10 million terajoules of energy? That's like, what, a kiloton bomb going off in each square meter of atmosphere over that square kilometer? A flash of light a billion times brighter than the sun? Is it better for the folk standing on the ground a few kilometers below, to be standing a few kilometers away from an energy release of a few million terajoules spread over a square kilometer rather than concentrated at a single spot - or is it like standing a few kilometers from the surface of a smallish sun?

Would it be better if we said the cloud expanded to hit a 20-kilometer radius of atmosphere? Or are we simply trading cremated humans and flash-fried landscape for humans flashburned with 2nd and 3rd degree burns and wildfires over hundreds of square miles from an energy release a million times brighter than the sun?

My initial guess is you've traded a massive ground blast for a massive high altitude flash without altering the fate of the folk on the ground all that much. No volcano to memorialize my act - just several square kilometers of seared desert.

 

[aramis]

What people tend to forget with asteroid is that shattering them also means spreading the energy out over more time as well as more volume. Shatter an asteroid 3 days out, and you have a constant infall for a 2 day window instead of a single large crunch. Yes, you heat things up, but you don't expose the core.

With a near-C (or even 0.2C or so) impact event is that popping it means spreading that energy out FAR further than a point impact, which means much more ability to recover from the event. I shoot a watermelon with a .454 cassul, I shatter it. I shoot it with a shotshell in that .454, and I crater it. Same energy delivered; but the ability of the target to dissipate the energy due to multiple not-quite simultaneous impacts is much better.

 

[BytePro]

Sensei Senseless say - Best to deflect, no good attempt you stop.

(For OP's 480 odd million kilometer 'attack run' one wouldn't have to vector a scout much to miss a 11,200 km diameter world - though that would be one spectacular 'fender bender'...)

As to detection - are there rules for system and world sensor ranges (which can benefit from massive baselines) - or just for spaceships?

Setting may imply this scenario doesn't occur - but I doubt the rules prevent it. Rationalizing most things in the context of the setting is an exercise in suspension of disbelief - and depends on what one wants in their own TU. If you want jump kinetic kill weaps - go for it. If you don't - 'prevent' it.

IMTU, the nature of jump transitions makes coming in 'too hot' subject to a natural deflection - a mechanic related to preventing jumping 'into' things that, as a side benefit, somewhat (but not completely) rules out the scenario the OP has presented. For practical (not suicidal, mind) purposes, very high velocities run the risk of catastrophic collisions - if for no other reason than reduced sensor range. Systems and worlds can have extensive sensor ranges and distributed weapon systems to counter most threats - but not all, at least all the time. I.e., no guarantees - if someone is motivated and ruthless enough - anything goes. In RL, history has show time and again that there are always vulnerabilities...