From root Tue Nov 7 08:30:20 1995 Received: from qrc.com (quark.qrc.com [198.178.200.5]) by mail.missouri.edu (8.6.11/8.6.11) with SMTP id IAA64828 for ; Tue, 7 Nov 1995 08:30:18 -0600 Received: from kromwill.dtek.chalmers.se by qrc.com with SMTP (5.65b/2.3-UTK) id AA17344; Tue, 7 Nov 95 09:29:40 -0500 Received: (from d9bertil@localhost) by kromwill.dtek.chalmers.se (8.6.9/8.6.9) id PAA03331 for gdw-beta@quark.qrc.com; Tue, 7 Nov 1995 15:29:46 +0100 Received: from [158.103.12.12] by hackes.dtek.chalmers.se (5.59+IDA+CTH/3.14+gl) id AA00936; Tue, 13 Jul 93 21:33:29 +0200 Received: by moeng2.morgan.edu (5.57/Ultrix2.4-C) id AA08323; Tue, 13 Jul 93 15:33:25 EDT Date: Tue, 13 Jul 93 15:33:25 EDT From: wildstar@qrc.com (Derek Wildstar) Message-Id: <9307131933.AA08323@moeng2.morgan.edu> To: d9bertil@dtek.chalmers.se Subject: Final Missiles Article Sender: d9bertil@qrc.com Status: RO Final Missiles Article -----8<----- MORE MISSILES FOR TRAVELLER: THE NEW ERA By Bertil Jonell with Guy Garnett. Contributions from Leonard Erickson (who suggested that penetration can be thought of in terms of cratering) and the Traveller Mailing List (general kibitzing). Featured missiles: Cannister, SFF, KE, KE(HE), proximity nuclear, and the LGB pseudo-missile. The detonation laser missile referred to in some cases below is the normal space combat missile, as detailed in Traveller: The New Era, page 349. The cannister missile is a kinetic energy weapon which releases a large number of small spheres which form a cloud approximately 750m in diameter. The SFF missile uses the 'self-forging fragment' phenomenon to produce a small number of penetrators, which do damage due to their kinetic energy. KE(HE) missiles are an inexpensive multi-role weapon, which can damage a space target by kinetic energy or a planetary target by explosive effects. Proximity nuclear missiles use a nuclear device as the warhead, and can damage their target by exploding on impact or by radiation effects. The LGB pseudo-missile allows a starship missile launcher to deliver laser-guided bombs against a ground target, when operating in support of planetary combat. Assumptions: Normal missiles are assumed to have a 150kg detonation laser warhead, 100kg of electronics, actuators etc., and 6750kg of engine. The engine consists of 6000kg of reaction mass and 750kg of structural components and power plant. The laser rods represent the largest part of the price of the detonation laser missiles. After that comes the nuclear warhead, the electronics and the engine which is a lower efficiency, and thus cheaper, model of the basic ship thruster. It is also assumed that all missiles weigh 7000kg and occupy a volume of 7m3. Cannister missile This missile releases 15,000 tungsten spheres (each sphere is 10mm in diameter, and weighs 10 grams) in a cloud to ensure that at least one of them hits the target. The cloud is usually released three seconds before impact (typically at a range of 50km). The exact range is automatically selected to achieve the maximum probability of a hit based on the closing velocity between the missile and the target. Cannister missiles may be used in an anti-missile role. The procedure is the same as attacking a ship, although most missiles are Micro or Sub-Micro sized, which will make them more difficult to hit. The damage comes from the kinetic energy of the spheres. The specific damage depends greatly on the closing speed of the missile and the target (see the 'Kinetic Damage Table' below). When used against surface targets on airless worlds the cannister missile attacks as a 3 round burst of automatic fire against each 10mx10m square in a 400m radius. Each hit has a damage and penetration given in the 'Kinetic Damage Table'. The missile must be modified before it can be used in this manner. These modifications are a Formidable task against the Gunnery (missiles) asset. A Difficult test of Electronics may be used to enable this task, since the modifications are primarily to the guidance package. The warhead of this missile weighs 150kg and the 100kg electronics package is assumed to contain simple terminal guidance, the mechanism that disperses the spheres, and a proximity fuse. Hitting a target with this missile is two levels more difficult compared to a normal detonation laser missile. As with a normal missile, apply the given damage 1D6 times. TL Price G-Turns 8 50k 10 9 50k 12 11 45k 12 13 40k 12 15 35k 12 SFF missile This missile uses the 'self-forging fragments' phenomena, a technique related to the shaped charges that are used in many anti-armor weapons, to generate several 100-gram metal fragments that hit the target. A few kilometers from the target the missile deploys and detonates several panels consisting of explosives on the back and metal that will form the fragments on the front (facing the target). SFF missiles may not be used in an anti-missile role (or against any other Micro or Sub-Micro targets). The damage comes from the kinetic energy of the fragments. The specific damage depends greatly on the closing speed of the missile and the target (see the 'Kinetic Damage Table'). When used against surface targets, the panels don't deploy. Instead the metal forms lethal fragments similar to how a normal artillery round works. In this case use the 'Surface Damage' ratings below. The warhead of this missile weighs 250kg and contains 150kg of explosives and 100kg of metal. The 100kg electronics package is assumed to include simple terminal guidance and a proximity fuse. Hitting a target with this missile is three levels more difficult compared to a normal detonation laser missile. As with a normal missile, apply the given damage 1D6 times. TL Price G-Turns Surface Damage 8 55k 8 C:100 B:60 Pen:50C 9 55k 11 C:100 B:60 Pen:50C 11 50k 11 C:100 B:60 Pen:50C 13 45k 11 C:100 B:60 Pen:50C 15 40k 11 C:100 B:60 Pen:50C KE missile This missile has no warhead. Instead it uses the impact of its dead weight at high speed to cause damage. The specific damage depends greatly on the closing speed of the missile and the target (see the 'Kinetic Damage Table'). The KE missile may not be used in an anti-missile role (or against any other Micro or Sub-Micro targets). When used against surface targets on airless worlds, use the procedures and rules given below under 'Kinetic Damage Vs Surface Targets'. The lack of warhead means that the dead weight only consists of the 100kg electronics package and the 750kg final weight of the engine and structure. The electronics package is assumed to include simple terminal guidance. Hitting a target with this missile is four levels more difficult compared to a normal detonation laser missile. On a successful hit, only apply the damage once. TL Price G-Turns 8 35k 12 9 35k 14 11 30k 14 13 25k 14 15 20k 14 KE(HE) missile. This missile has a 1000kg High Explosive warhead optimized for use against surface targets. When used in space combat its explosive effect is ignored since it is so minuscule compared to the kinetic energy of the impact. The KE(HE) missile does more damage in space combat not because of the explosive warhead, but because it has 1000kg more mass than the lighter KE missile when it impacts the target. The specific kinetic damage depends greatly on the closing speed of the missile and the target (see the 'Kinetic Damage Table'). KE(HE) missiles may not be used in an anti-missile role (or against any other Micro or Sub-Micro targets). When used against surface targets, the explosive warhead is detonated on impact, similar to how a normal artillery round works. In this case use the 'Surface Damage' ratings below. The warhead of this missile is a 1000kg HE charge. The 100kg electronics package is assumed to include simple terminal guidance. Hitting a target in space combat with this missile is four levels more difficult compared to a normal detonation laser missile. On a successful hit, only apply the damage once. TL Price G-Turns Surface Damage 8 40k 4 C:100 B:75 Pen:175C 9 40k 4 C:100 B:75 Pen:175C 11 35k 5 C:100 B:75 Pen:175C 13 30k 6 C:100 B:75 Pen:175C 15 25k 7 C:100 B:75 Pen:175C Proximity Nuclear missile This missile carries a nuclear warhead intended to detonate at a pre-selected distance from the target. When a nuclear weapon detonates in space, the major part of the energy will be released in the form of so-called 'soft' x-rays. This radiation is absorbed by almost any solid object and creates, through thermal expansion, a shock wave inside the object. Damage depends on the yield of the warhead and the range at which it was detonated, see the 'Nuclear Damage' procedures below. Proximity nuclear missiles may be used in the anti-missile role. The procedure is the same as attacking a ship, although most missiles are Micro or Sub-Micro sized, which will make them more difficult to hit. Any hit, at any detonation distance, will destroy a missile. When used against surface targets, the nuclear warhead can be detonated as an airburst or on the surface. The effects of nuclear weapons on ground targets is outside the scope of this article. Several warheads of different yields are available. All of the warheads available for this missile weigh 250kg or less. The 100kg electronics package is assumed to include simple terminal guidance and a proximity fuse. The gunner chooses the detonation distance of this missile before launch. Closer range increases the damage inflicted but makes it harder to achieve a hit. There are three basic distances: contact, close proximity (several hundred meters), and far proximity (several kilometers). Contact: hitting a target in space combat with the missile is four levels more difficult compared to a normal detonation laser missile. Close Proximity: Hitting a target in space combat with the missile is three levels more difficult. Far Proximity: Hitting a target in space combat with the missile is two levels more difficult. On a successful hit, only apply the damage once. Missiles TL Price G-Turns 8 35k (+warhead) 10 9 35k (+warhead) 12 11 30k (+warhead) 12 13 25k (+warhead) 12 15 20k (+warhead) 12 Warheads Yield Price 50t 10k 100t 15k 500t 20k 1kt 30k 2kt 50k 5kt 70k 10kt 100k 20kt 200k 50kt 500k 100kt 1M LGB pseudo-missile This is, as the name states, not a real missile. Instead it is a missile-shaped container with 6 1000kg laser-guided bombs. There is empty space inside the container but the weight of the bombs limits their number to six. The container is fired as a normal missile and the communication laser of the missile turret can be used to designate a surface target from up to 10,000m altitude. Above this altitude (or if bad weather on the surface will obscure the laser) another unit closer to the surface will have to handle the designation. The individual bombs are not capable of atmospheric re-entry in any atmosphere more dense than Very Thin. If they are used to attack a target on a world with thicker atmosphere, the ship has to be inside the atmosphere at the time of launch. A version carrying 6 bombs where each bomb has ablative heat shielding that enables them to be deployed from orbit over worlds with an atmosphere of Dense or thinner is available for twice the cost. The spread can be chosen: The bombs can either all hit at the same time or with up to 5 seconds of separation. This type of 'missile' can *not* hit a ship unless it stands still on the ground. TL Price Surface Damage 8 22k C:190 B:80 Pen:90C 9 18k C:190 B:80 Pen:90C 11 14k C:190 B:80 Pen:90C 13 12k C:190 B:80 Pen:90C 15 10k C:190 B:80 Pen:90C COMBAT RESOLUTION Space combat: Because a range band in space combat is so large, even when compared to the 'far proximity' range of a nuclear device, the missiles described in this article have the difficulty of their to-hit rolls increased. These increases are summarized in the 'Missile Difficulty Table' below. A Master Fire Director may ignore some or all of these difficulty increases. Intercept: In order to intercept their target, missiles must maneuver to arrive in the same range band as their target (first maneuvering to get the closest approach distance to zero), just like an ordinary detonation laser missile. Once in the same range band, the missile begins its terminal approach. In order to successfully intercept the target during this terminal approach, the missile must have more G-turns of fuel remaining than the target's current G rating (maneuver performance). This fuel is spent achieving an intercept, compensating for target evasion, and for course corrections during the terminal approach. Short Ranges: At short ranges, a missile may not be able to use its full acceleration before it impacts the target, limiting the impact velocity. Any missile fired when the distance to the target, in range bands, is less than or equal to half of the maximum acceleration of the missile, in Gs, is at short range. Missiles at short range receive a -1 Difficulty modifier to the targeting roll, but may not use more acceleration than twice the number of range bands to the target. For example, a 12 G-turn missile fired at a range of 4 will receive a -1 Difficulty modifier, but may use no more than 8 G-turns of acceleration before impacting the target. Missiles may be fired at ranges as short as 250km; this is the minimum range required for the missile to arm itself and lock onto the target. The 'Short Range Velocity Table' below gives the final velocity of the missile (in range bands per turn) for different accelerations and ranges. Terminal Approach: Once a missile is in terminal approach, any beam weapons that are ready to fire may fire at it before it intercepts the ship. This pre-emptive defensive fire takes place during the missile's terminal approach, before it reaches the target ship. This fire is resolved as any other beam weapon fire. Nuclear dampers may be used against proximity nuclear missiles during their final approach; resolve this the same way as against normal detonation laser missiles. The terminal approach may last longer than a single phase. In this case pre-emptive defensive fire may take place during any or all of these phases. Consult the 'Time to Impact Table' below to determine the total number of phases during which pre-emptive defensive fire may be conducted. As an optional rule, a +1 difficulty modifier is applied to defensive fire targeting missiles that have a closing speed of more than 10. Planetary combat: Those missiles which can attack a surface target do so as laser-designated artillery, except for cannister missiles. See Traveller: The New Era, pages 282 and 278. Cannister missiles are orbital indirect fire, and cannot be designated. See pages 280-281 of the Traveller rules. COMBAT TABLES Missile Difficulty Table Class Used by Difficulty Distant Detonation Lasers -- Far Proximity Cannister, Proximity Nuclear +2 Near Proximity SFF, Proximity Nuclear +3 Impact KE, KE(HE), Proximity Nuclear +4 Short Range: -1 Difficulty if the range to the target, in range bands, is less than or equal to the acceleration of the missile, in Gs. Time to Impact Table Closing Time in Speed Phases 1 10 2 5 3 3 4-5 2 6-10 1 11+ 1 (High-Speed Target) High-Speed Targets: (optional rule) Pre-emptive defensive fire attempts are +1 Difficulty if firing on missiles with a closing speed of more than 10. Short Range Velocity Table Acceleration Distance to target in km in Gs 250 500 1000 2500 5000 10000 20000 1 0.13 0.18 0.25 0.40 0.56 0.79 1.12 2 0.18 0.25 0.35 0.56 0.79 1.12 1.59 4 0.25 0.35 0.50 0.79 1.12 1.59 2.24 6 0.31 0.43 0.61 0.97 1.37 1.94 2.75 8 0.35 0.50 0.71 1.12 1.59 2.24 3.17 10 0.40 0.56 0.79 1.25 1.77 2.51 3.55 12 0.43 0.61 0.87 1.37 1.94 2.75 3.89 14 0.47 0.66 0.94 1.48 2.10 2.97 4.20 The number in the body of the table is the speed of the missile, in range bands per turn, after traveling the stated distance at a given acceleration. KINETIC DAMAGE Kinetic Damage: If two solid objects collide at speeds measured in tens of thousands of kilometers per hour, parts of them will instantly vaporize into a very brief 'fireball' of plasma. If the objects are very dissimilar in size, as for example a missile and a spaceship, the missile will vaporize completely and blow a crater in the hull of the ship. The diameter of the crater in centimeters is equal to the damage rating given for the missile on the 'Kinetic Damage Table'. Direct Kill: (optional rule) If a ship is hit with a cratering weapon with a large enough penetration, the weapon will simply 'penetrate away' the entire ship. Cannister, SFF, KE, and KE(HE) missiles and the physical damage of a contact nuclear explosion are cratering weapons; lasers, detonation lasers, x-ray concussion damage, and the various small anti-armor weapons are not. Consult the table below. If the ship's displacement is less than the number given, it will suffer the effect. Destroyed ships are probably blown into several large parts. Annihilated ships are vaporized. Kinetic Damage Vs Surface Targets: An atmosphere figure of 1+ will cause a missile going at these speeds to break up and disintegrate before reaching the surface, so worlds with atmospheres are protected against attacks with KE and cannister missiles. Dual-role missiles carrying an explosive warhead like the KE(HE), SFF, and proximity nuclear can choose to enter the atmosphere slowly enough to survive until impact. If a missile inflicting kinetic damage hits a surface target on an airless world it will do damage as stated under 'Kinetic Damage' above and create a crater of the given size. The vaporized material rushing out from the point of impact will also create a concussion effect similar to that generated by an explosion in an atmosphere equal to half the penetration. Depending on the surface, it is possible (although unlikely) that a fragmentation effect will be generated as well. Kinetic Damage Table Impact Speed Damage by Warhead Type (G-turns) KE KE(HE) Cannister SFF 1 1-1020 1-1280 1-34 1-68 2 1-1560 1-1960 1-51 1-102 3 1-2000 1-2500 1-65 1-131 4 1-2360 1-2980 1-78 1-155 5 1-2700 1-3380 1-89 1-178 6 1-3000 1-3780 1-100 1-198 8 1-3560 1-4300 1-118 1-236 10 1-4080 1-5180 1-135 1-270 15 1-5200 1-6560 1-172 1-344 20 1-6200 1-7980 1-205 1-408 30 1-7800 1-9940 1-262 1-522 Direct Kill Table Maximum Displacement Penetration Destroyed Annihilated 250 5 - 500 40 1 1000 300 5 1500 1000 15 2000 2300 40 2500 4700 80 3000 8000 130 4000 19000 300 5000 37000 580 6000 64000 1000 7000 100000 1600 8000 150000 2400 9000 220000 3400 10000 300000 4600 12000 500000 8000 18000 1700000 27000 25000 4500000 75000 NUCLEAR DAMAGE Contact Detonation: If a nuclear weapon is detonated in contact with the target vessel, the resultant plasma fireball and high-speed fragments will cause direct physical damage to the target as indicated in the 'Physical Damage' column of the 'Nuclear Warhead Damage' table below. Apply this damage to the location hit. Radiation from the blast will also damage the target; the penetration and damage value are given in the 'X-Ray Concussion' column of the table. Apply this damage to the location hit as well. If the optional 'Direct Kill' rule is being used, it applies to the physical damage but not the x-ray concussion damage. Proximity Detonation: The plasma fireball and high-speed fragments are a short-range effect, and dissipate (mostly) harmlessly in space if the weapon is not detonated in contact with its target. When a nuclear weapon detonates in space, the major part of the energy will be released in the form of so-called 'soft' x-rays. This radiation is absorbed by almost any solid object and creates, through thermal expansion, a shock wave inside the object. To calculate the damage inflicted from soft x-ray concussion, divide the contact x-ray concussion damage, from the 'Nuclear Warhead Damage' table below, by the factor dependent on the size of the ship and the detonation range, from the 'Soft X-Ray Concussion' table. This damage has a penetration of 1/4, and is inflicted on more than one area of the ship. The number of areas is given on the 'Soft X-Ray Concussion' table. If there isn't enough damage to even cause one major hit, inflict one minor hit to one area. Each location hit also receives radiation and EMP damage as if it were hit by a particle accelerator (See Traveller: The New Era, page 322). Note that the armor isn't actually penetrated. Instead the shock wave is generated inside the armor and travels towards the interior of the ship. Nevertheless, armor does have an effect in lessening the impact. The areas affected should be the ones most facing the explosion, as chosen by the referee (refer to the picture on page 319 of Traveller: The New Era). Larger ships absorb more damage than small ones because they, due to their size, absorb a larger proportion of the bombs energy. On the other hand, their systems are usually able to withstand much more damage. Other Effects: Nuclear explosions generate considerable amounts of hard radiation as well. This radiation is dangerous to people and equipment, but the x-ray effects are usually much more severe. Spacecraft hulls incorporate enough radiation protection that computing these effects are not normally necessary. If it becomes necessary to calculate radiation exposure, a dose of 1000rem will incapacitate a human with 30 minutes, and is 100% fatal within two weeks. A dose of 5000rem incapacitates within a few minutes, and is fatal within two days. Starship hulls reduce the radiation dose by 1/3000th or more. A well-protected military starship, like the SDB, reduces radiation exposure by 1/100,000th at Average Stellar, and up to 1/10,000,000th at High Stellar tech levels. Small craft and civilian spacecraft with thin, unarmored hulls, may be less well protected at the referee's option. The 'Nuclear Warhead Damage' table lists the radiation from the warhead at the various ranges (1krem = 1000rem, 1Mrem = 1,000,000rem). The effects of nuclear weapons on ground targets is beyond the scope of this article. Nuclear Warhead Damage Contact Detonation Radiation Damage Physical X-Ray Contact Proximity Detonation Yield Damage Concussion Detonation Close Far 50t 1-570 1/4-1100 50krem 3krem nil 100t 1-810 1/4-1600 100krem 5krem nil 500t 1-1800 1/4-3600 300krem 10krem nil 1kt 1-2500 1/4-5100 500krem 30krem nil 2kt 1-3600 1/4-7200 1Mrem 50krem nil 5kt 1-5700 1/4-11000 3Mrem 100krem nil 10kt 1-8100 1/4-16000 5Mrem 300krem nil 20kt 1-12000 1/4-23000 10Mrem 500krem nil 50kt 1-18000 1/4-36000 30Mrem 1Mrem 1rem 100kt 1-25000 1/4-51000 50Mrem 3Mrem 3rem Soft X-Ray Concussion Close Proximity Far Proximity Displacement Divide by Areas Hit Divide by Areas Hit 10 420 10 4200 10 20 330 10 3300 10 50 240 10 2400 10 100 200 10 2000 10 200 150 9 1500 10 500 110 9 1100 10 1000 90 9 900 10 2000 70 9 700 10 5000 50 9 500 10 10000 40 8 400 10 20000 30 8 300 10 50000 25 7 250 10 100000 20 7 200 10 200000 15 6 150 10 500000 11 6 110 10 1000000 9 5 90 10 -----8<----- Designers' Notes The kinetic damages were computed using the tables on crater size in 'The Effects of Nuclear Weapons'. The penetration was assumed to be equal to the crater radius in hard dry rock from a nuclear explosion developing the same energy as the kinetic impact. The 'Direct Kill Table' was developed from noting at what point the crater diameter due to the damage of the weapon exceeded the diameter of the notional standard target ship (assumed to be a sphere) of a given tonnage. Nuclear weapons prices were taken from Striker but modified somewhat in the lower end of the scale. Proximity nuclear effects in space were calculated based on the assumptions that the only way of damaging the target was by radiation, that most of the energy of the explosion is in the form of 'soft' x-rays, and that the nuclear weapon could be treated as a point source of radiation. Close Proximity was assumed to be 300m, and Far Proximity was computed at 3km. We have read, and believe we understand, Dave Nilsen's objections to HE missiles in Traveller space combat. We have worked out the impact and damage mechanisms for these missiles to the point where we feel that they can work with the technology postulated for Traveller: The New Era. They are based on classical Newtonian physics, and make use of principles similar to that outlined for the U.S. Strategic Defense Initiative's 'Smart Rocks' and 'Brilliant Pebbles' proposals. Bertil Jonell d9bertil@dtek.chalmers.se Guy Garnett wildstar@moeng2.morgan.edu