I allow guidance systems in continuous burn missiles.
SS3 standard missile and continuous burn propulsion
- Thread starter Carlobrand
- Start date
The inconsistency is in the total delta-V available given TL6 propulsion methods and fuels. In other words, to have 1G1 performace given the available TL 6 technology would be a strain on credulity; to have 6G performance for a full 1000 second turn.
Small issue - even in CT, the ship combat turn is not consistently defined.
CT Bk2-77: 10 minutes (p 22)
CT Bk2-81: 1000 seconds (p 26)
CT TTB: 1000 seconds (p 72)
CT Starter: 1000 Seconds (Bk 1 p 39)
CT Bk5-79: 20 minutes (P 36)
CT Bk5-80: 20 minutes (p 38)
Mayday: 100 minutes (p 3)
The same missile designs are used for all of them (except HG) with the same ratings.
Let's look at TL6's best rocket ever in terms of sustained thrust: 700 seconds, peak of 4G's. Total payload mass, typical: 46.98, total launcher mass: 131+payload.
Spoiler:
For the lazy or math challenged: 1000 seconds is 16 minutes 40 seconds.
I always have, too.
That's what I thought that HG_B meant as well, until he corrected my misunderstanding with this:
So Aramis,
Welcome to the '1,000 light years' club.
That's actually pretty interesting.
Some personal thoughts:
If I understand you and rockets correctly, the Saturn V was capable of 5G* (4G acceleration + Earth Gravity since it was going straight up) for 0.7 turns (1000 second turns).
Per SS3, a standard missile is 50 kg with an 11 kg warhead (10 kg High Explosive + 1 kg Proximity Detonator).
Rockets scale pretty darn linearly, so the Saturn V 'launcher' is about 2.8* x 'payload' making a Mini-Saturn V with an 11 kg payload = 31 kg for the launcher and 11 kg for the payload = 42 kg total missile weight for a TL 6 missile capable of 5G* for 0.7 turns.
OK, the rules don't model reality perfectly, but that seems pretty close to this layman.
* [As an aside, your payload mass fraction seems high at first glance, but I haven't really taken staging into proper consideration so it may well be correct ... the Saturn V varies from about 0.5G to 4G (1.5G to 5G in space) so it is probably closer in performance to a 3.25 Gee missile.]
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No, it's only capable of 4G - the profile is based upon the G's measured on the accelerometer, and it's not 0'd at launch. (The shuttle actually experienced more G's...)
And it really isn't capable of sustained 4G's; due to staging, it ramps from 1.5 to 4 in the first 70 seconds, then from 1.5 to about 3.5, then 1.1 to about 2.
Gross mass at takeoff of 5,000,000 lbs, thrust of 7,648,000 lbs, that's 1.52 initial G's, and if you watch launch footage, it's going up half as fast as its rhime icing is falling down. On the near empty Stage 1, it's only getting 4.7G's peak.
All before subtracting for the local gravity.
Note that this excludes the CM/SM/LM stages; they're payload.
Further, it's a liquid fuel monstrosity using the best energy to mass ratio fuel, despite its insane difficulties and dangers.
And it really isn't capable of sustained 4G's; due to staging, it ramps from 1.5 to 4 in the first 70 seconds, then from 1.5 to about 3.5, then 1.1 to about 2.
Gross mass at takeoff of 5,000,000 lbs, thrust of 7,648,000 lbs, that's 1.52 initial G's, and if you watch launch footage, it's going up half as fast as its rhime icing is falling down. On the near empty Stage 1, it's only getting 4.7G's peak.
All before subtracting for the local gravity.
Note that this excludes the CM/SM/LM stages; they're payload.
Further, it's a liquid fuel monstrosity using the best energy to mass ratio fuel, despite its insane difficulties and dangers.
I don't think anyone disagrees that the Trav missiles are a case of misapplied phlebotimum:
http://tvtropes.org/pmwiki/pmwiki.php/Main/MisappliedPhlebotinum
The propellants are fantastic stuff. A kilo of the continuous-burn solid stuff can throw 50 kilograms at a G for at minimum a thousand seconds. Now try to imagine that stuff in general use: a couple grams of the stuff is all you'd need to get a 5 kilo shoulder-launched missile up past the speed of sound. Heck, the exhaust from such a burn would be wickedly fast - that alone could be weaponized. And, the limited burn fuel is even better.
And then there's the liquid fuel. It would bring a revolution to combat aircraft.
Clearly they intended to add to the game experience by introducing missiles to space combat. Mayday/Book-2 with just lasers is rather bland.
Just as clearly, the scale involved makes it impossible to do this without introducing some fantastic uber-fuel. They could shrink the scale to something more appropriate, but that brings different problems - most notably there's basically no chance of reaching jump limit or having someone come to your rescue before the battle's decided. Certain roleplay implications there.
And, equally clearly, the full implications of the uber-fuel - most notably, the potential for kinetic-kill missiles and the potential for this same fuel's use in other Traveller settings - were not fully realized.
Choice then boils down to killing the beast, tolerating it, or embracing it and bringing its mutant offspring to full fruition.
http://tvtropes.org/pmwiki/pmwiki.php/Main/MisappliedPhlebotinum
The propellants are fantastic stuff. A kilo of the continuous-burn solid stuff can throw 50 kilograms at a G for at minimum a thousand seconds. Now try to imagine that stuff in general use: a couple grams of the stuff is all you'd need to get a 5 kilo shoulder-launched missile up past the speed of sound. Heck, the exhaust from such a burn would be wickedly fast - that alone could be weaponized. And, the limited burn fuel is even better.
And then there's the liquid fuel. It would bring a revolution to combat aircraft.
Clearly they intended to add to the game experience by introducing missiles to space combat. Mayday/Book-2 with just lasers is rather bland.
Just as clearly, the scale involved makes it impossible to do this without introducing some fantastic uber-fuel. They could shrink the scale to something more appropriate, but that brings different problems - most notably there's basically no chance of reaching jump limit or having someone come to your rescue before the battle's decided. Certain roleplay implications there.
And, equally clearly, the full implications of the uber-fuel - most notably, the potential for kinetic-kill missiles and the potential for this same fuel's use in other Traveller settings - were not fully realized.
Choice then boils down to killing the beast, tolerating it, or embracing it and bringing its mutant offspring to full fruition.
Timerover51
SOC-14 5K
I keep debating throwing some real world physics into the discussions, but not sure if it worth the effort.
I simply do not use missiles for space combat.
I simply do not use missiles for space combat.
It'd be a shame to get rid of missiles altogether. Simplifies the CT game too much, just ships beaming at each other. On the other hand, the SS3 description has all that unintended consequence business attached to it, and the best in-game small motor in the game that I know of - a fusion drive out of MegaTraveller - still can't produce the results.
A semi-realistic option is to grab that fusion drive and then use the missile as a kind of mine, dropping it in your wake and hoping you can lead the following enemy over it, then firing it up at a range of a few thousand kilometers to hit him - or at least use that prospect to persuade him not to pursue you too vigorously.
Alternatively, we need to come up with an acceptable fictional drive that does the job without inviting a major revolution in ground warfare. That means scrapping most of SS-3's drive info and imposing a fictional drive with specific performance characteristics that suit our needs - or perhaps a set of several drives with differing characteristics so we get some variety going. We seem to be content with the idea of a fictional drive for the starships we're piloting, so that's not a completely crazy idea.
Or both. Use the fusion drive at about TL 9 for missile-mines, then introduce some sort of maneuver-drive-based burnout drive at TL10.
A semi-realistic option is to grab that fusion drive and then use the missile as a kind of mine, dropping it in your wake and hoping you can lead the following enemy over it, then firing it up at a range of a few thousand kilometers to hit him - or at least use that prospect to persuade him not to pursue you too vigorously.
Alternatively, we need to come up with an acceptable fictional drive that does the job without inviting a major revolution in ground warfare. That means scrapping most of SS-3's drive info and imposing a fictional drive with specific performance characteristics that suit our needs - or perhaps a set of several drives with differing characteristics so we get some variety going. We seem to be content with the idea of a fictional drive for the starships we're piloting, so that's not a completely crazy idea.
Or both. Use the fusion drive at about TL 9 for missile-mines, then introduce some sort of maneuver-drive-based burnout drive at TL10.
pendragonman
Absent Friends Margrave
Well torpedoes were once what anti ship mines were called. That is what Admiral Dewey meant when he said "Damn the torpedoes, full speed ahead"
IIRC, in one of the Traveller Digest magazines, there were specifications for a "Backpack Propulsion Unit" for use with a Vacc-Suit during EVA. The TL-15 version used a miniature "Thruster Unit" (= M-Drive). So, in MT at TL-15 you can have a miniature Thruster Propulsion unit that is good for stable long duration reusable service.
The question would be, at what TL can you make a small Thruster-unit/Battery combination that runs hot and will burn out after an extremely limited duration service life?
And that is saying nothing of gravitic drives, which should be able to be made small much earlier.
It could make for some interesting tactical considerations: gravitic propulsion good out to about 10 dia from a mass, thruster propulsion good to unlimited distance (in MT, at least).
Timerover51
SOC-14 5K
That was Admiral Farragut at Mobile Bay in August of 1864. When Dewey attacked the Spanish at Manila Bay in 1898, mines were no longer called torpedoes, as the Whitehead Torpedo was developed in 1867, and widely available. Dewey's quote is: "You may fire when you are ready, Gridley."
As pointed out by D. K. Brown in his book, Warrior to Dreadnought, the torpedo threat to ships, especially warships moving at a high rate of speed was badly over-rated if you were talking either torpedo-boats or destroyers. The submarine posed a totally different threat.
Timerover51
SOC-14 5K
I have more problems with missiles than just the thruster unit. The missile example that started the discussion is as follows.
I will not get into a discussion of at 1 kilogram mass sensor being able to distinguish between the adjacent mass of the firing ship verses the very distant mass of the target.
The warhead is TL 6, along with a TL 6 proximity fuze. Presumably, that means the missile cannot be relied on for a direct hit. The warhead has to be fragmentation, as blast is a meaningless concept in a vacuum. A High Explosive Plastic/Squash Head warhead is ruled out by the need for a nose sensor.
In Supplement 7, Traders and Gunboats, there is a good description of the amount of damage interior partitions and bulkheads on a commercial ship will take. To put a man-size, say one meter diameter, hole in an interior partition requires 100 damage points from an energy weapon, 100 damage points from an explosive charge, or 1000 damage points from a projectile weapon. For a man-size hole in a bulkhead, 1000 damage points from either an energy weapon or explosive charge are required, with projectile weapons being useless. Deck floors are treated as bulkheads.
In the Double Adventure 5, Chamax Plague and Horde, 100 points of acid damage will breach an interior partition, 1000 points of damage a bulkhead. However, the Chamax also, using acid, burn one meter holes in the hull of the Shaarin Challenger and the derelict pinnace. Given that, it would appear that the strength of the hull plating is very similar to that of the bulkheads.
Now, when I think of small arms for penetrating any type of ballistic plating, I think serious small arms, like a .30-06 firing AP ammo at close range. My penetration charts indicate that to order to have only a 5% change of penetration by that round at normal impact and close range, you need either 1.1 inch of mild steel plate weighing 43.1 pounds per square foot, or 0.75 inches of special treated (i.e. ballistic) steel at 30 pounds per square foot. That means that your bulkheads and hulls are thicker and stronger than that, and your interior partitions are pretty thick too (read not light weight as one would think).
A 10 kilogram fragmentation warhead is not even going to dent that thick a hull, so drop the proximity fuze, nor is it going to punch a hole in by simply detonating. Now, a direct hitting High Explosive Plastic/Squash Head round of roughly 4 to 6 inch diameter will blast a 6 to 8 inch diameter disc out of that thick a hull and project it into whatever compartment is impacted. A space ship is not a very congested and small volume as a tank, so your chances of crippling damage are very small.
If you really want serious missiles in the game, then start talking ones that weight in the hundreds to thousands of kilograms, and cost serious money, like 500K Credits on up.
I will not get into a discussion of at 1 kilogram mass sensor being able to distinguish between the adjacent mass of the firing ship verses the very distant mass of the target.
The warhead is TL 6, along with a TL 6 proximity fuze. Presumably, that means the missile cannot be relied on for a direct hit. The warhead has to be fragmentation, as blast is a meaningless concept in a vacuum. A High Explosive Plastic/Squash Head warhead is ruled out by the need for a nose sensor.
In Supplement 7, Traders and Gunboats, there is a good description of the amount of damage interior partitions and bulkheads on a commercial ship will take. To put a man-size, say one meter diameter, hole in an interior partition requires 100 damage points from an energy weapon, 100 damage points from an explosive charge, or 1000 damage points from a projectile weapon. For a man-size hole in a bulkhead, 1000 damage points from either an energy weapon or explosive charge are required, with projectile weapons being useless. Deck floors are treated as bulkheads.
In the Double Adventure 5, Chamax Plague and Horde, 100 points of acid damage will breach an interior partition, 1000 points of damage a bulkhead. However, the Chamax also, using acid, burn one meter holes in the hull of the Shaarin Challenger and the derelict pinnace. Given that, it would appear that the strength of the hull plating is very similar to that of the bulkheads.
Now, when I think of small arms for penetrating any type of ballistic plating, I think serious small arms, like a .30-06 firing AP ammo at close range. My penetration charts indicate that to order to have only a 5% change of penetration by that round at normal impact and close range, you need either 1.1 inch of mild steel plate weighing 43.1 pounds per square foot, or 0.75 inches of special treated (i.e. ballistic) steel at 30 pounds per square foot. That means that your bulkheads and hulls are thicker and stronger than that, and your interior partitions are pretty thick too (read not light weight as one would think).
A 10 kilogram fragmentation warhead is not even going to dent that thick a hull, so drop the proximity fuze, nor is it going to punch a hole in by simply detonating. Now, a direct hitting High Explosive Plastic/Squash Head round of roughly 4 to 6 inch diameter will blast a 6 to 8 inch diameter disc out of that thick a hull and project it into whatever compartment is impacted. A space ship is not a very congested and small volume as a tank, so your chances of crippling damage are very small.
If you really want serious missiles in the game, then start talking ones that weight in the hundreds to thousands of kilograms, and cost serious money, like 500K Credits on up.
Most people do. Your Supplement 7 citation also says, "Bullet firing weapons are ineffective against bulkheads." That to me suggests that fragments are going to have a bit of trouble. I've got an interesting link noting fragment velocities about double that of your 30-06,
www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0441810
but I don't know that it makes enough difference.
Cutting bulkheads with weapon lasers always struck me as being rather like trying to cut leather with a needle, but I figure maybe the thing had a selector setting that allowed it to be used as a cutter instead of a penetrator, allowing it to double in a pinch as a tool for getting through doors or cutting trees. Anyway, calculating from the lasers and drawing on Striker gave me something like a 1 cm interior wall and a 10 cm bulkhead, but your numbers put you pretty close to the Striker/High Guard hull walls, which were equivalent to 33.6 cm of steel in penetration resistance. In either case, a fragment's just going to bounce off the hull without doing much more than leaving a light gouge.
The SS3 missile is basically hopeless under the Striker/High Guard conversion. A High Guard-design ship won't just shrug off the fragmentation warheads; it'll shrug off the HE impact warheads a missile could mount, and it only takes a couple or three levels of armor for it to shrug off the HEAP rounds as well. That once more leaves us with a space missile that's using some type of warhead that would revolutionize ground combat if it were only in the ground game.
I don't have a solution there, since any more powerful warhead able to fit the missile payload is just as good a candidate for use by ground troops. You'd have to envision a warhead that was useful in space but not effective in atmosphere, and the only candidate that comes to mind is a straightforward kinetic kill warhead.
Same issue with the mass sensor: the only available mass sensor in that size, according to MegaTrav, can only tell direction to the largest mass within range, a rather unfortunate guidance system to use on a large ship that might have to launch missiles against small boats - and gods help you if you need to launch anywhere near a planet. That fortunately is an easier fix - slip in a different guidance system.
pendragonman
Absent Friends Margrave
That's what I get for posting on little sleep. Thanks for the correction.
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