[Forwarded to the files by the Benevoleny Tyrant Regent] To: GURPSnet From: John Fosgett Subject: Hyperspace Physics 101 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" With all of the discussions going on about reactionless thrusters, jump drives, etc, I thought everyone would be interested in this. I've removed the tabs from the tables, so they should come out alright with most window sizes. :) Comments Welcome! (I'd like to polish off the rough edges and maybe post this to the ftp site.) Hyperspace Physics 101 Preface: Since the invention of flight, mankind has imagined ways to travel to the stars. The biggest barrier to interstellar travel has been the so called ‘light speed limit’. Without the ability to travel faster than light, mankind is forced to use STL spacecraft to explore the universe. This means that it would be almost impossible to reach even the nearest stars within a man’s life span. For gaming purposes, this is very boring. Abstract: The purpose of this essay is to theorize various methods of propulsion that will readily allow travel both within a stellar system and between stellar systems in a reasonable (i.e. playable) time frame. These propulsion systems will need to have at least some basis in real world physics, and require only a minimum suspension of disbelief. Discussion: For STL travel within a star system, we have several propulsion systems at our disposal. These systems fall into two broad categories; reaction engines and reactionless drives. Reaction engines are well documented in GURPS Vehicles and their principles of operation are straight forward and easily understood. However, Reactionless Drives are only vaguely described and largely left to individual GM’s to describe. The usual result of this is a complete lack of cross compatibility between game worlds ran by different GM’s. GURPS Vehicles lists several categories of reactionless drives of varying efficiencies, but without much explanation of how such drives might operate. This is understandable, since every GM will have her/his own idea of how they work. All that is important is the drive’s statistics (mass/volume, power, thrust, and cost) plus any special effects. FTL drives are treated even worse. The usual result is a game universe filled with vastly different alien cultures with absolutely identical propulsion systems. Granted, that is a GM call, but what if there wasn’t just one way to get around space? What if there were several different approaches that would work, each with their own advantages and drawbacks? In the following text, I will describe three different STL reactionless drives and several variant FTL drives. Each will have their own unique characteristics, including progression at higher tech levels, and also some special effects and design features. Lastly, each will detail the interactions between STL and FTL drive systems. Photonic/Tachyon Drives: The first drive to be discussed makes its appearance at TL9 as the ‘Standard Thruster’. These drives are a result of early research in the field of gravitics, but are not gravitic devices. They operate by generating interactions between electromagnetic waves to produce short lived particles. This is accomplished by colliding tachyons and photons to produce mesons along with soft X-rays They are characterized by low power to weight ratios, radioactive exhaust, and poor power efficiency (compared to other reactionless drives). At higher tech levels, the half-life of the thrust products drops to safer levels, but never becomes entirely ‘clean’. One interesting side effect of the energetic exhaust from these drives is that they can be used much like a fusion rocket by injecting a reaction mass into the exhaust chamber for increased performance. However, to utilize this effect it is necessary to adjust the primary output products to optimize the energy transfer to the secondary reaction product. This has the added benefit of dampening some of the hard radiation in the exhaust stream. Typically water is used for this purpose since it is extremely abundant and cheap, but other fuels could be used. When operating within an atmosphere (if permitted by the local government) Photonic Drives can operate as fusion air-rams to conserve fuel. This makes them ideal for surface-to-orbit transfers. Space warfare will also benefit, since ships can achieve short duration high acceleration burns or cruise long distances on PTD thrusters alone. Reactionless Thruster Table (Photonic/Tachyon Drives) TL9-11+ TL Type Wt(lbs) Pwr(kw) Afterburner Fuel(GPH) Cost/lb 9 Standard 1 .5 x20 .8 $25 10 Advanced .5 .5 x20 .4 $20 10 HP Adv .25 .5 x20 .4 $100 11 Super .2 .25 x10 .08 $20 11 HP Super .1 .25 x10 .08 $100 (*Note: Fuel is only used when using afterburner injection outside of an atmosphere. Power is used at all times.) Weight, Power, Cost: Multiply by engine thrust in pounds. Afterburner: This is a multiple applied to the rated thrust when using a secondary reaction mass. Fuel: Multiply by base thrust to calculate GPH consumed. Volume: Volume (in cf) is equal to weight/125. Gravionic Drives: The next drive does not appear until TL10. These drives are a direct result of major breakthroughs in gravity manipulation technology. Gravionic Drives produce thrust by manipulating energy within the boundary layer between N-space and Jump space known as Subspace. A good analogy would be the propellers of a wet navy surface ship pushing water to propel the vessel through the sea. The Gravionic drives attempt to displace energy into Subspace and are continually repulsed, which provides thrust. The result is a highly efficient thruster with very little harmful side effects. The hull of a Gravionic ship will become highly positively charged during its transit which will require space docks to be equipped with special discharging mechanisms. The fees for docking can be partially offset by selling this power to the docking facility. Gravionic Drives produce some exhaust, mostly in the form of negative ions and waste heat. At higher TL’s the waste heat problems are minimized, but the high energy ionic stream is unavoidable with this design. Gravionic Drives are non-Newtonian in the sense that the their acceleration effects the entire ship as a single, unique, frame of reference (hence the ‘Grav’ part of the name). The ship and everything in it will not experience acceleration effects, allowing the ship to realize the full acceleration potential of the drive (between 20 and 500 G’s max). Much like Photonic/Tachyon Drives, Gravionic Drives can gain some benefit from injecting reaction matter into their exhaust, albeit for a different purpose. Increasing the amount of negative ions in the exhaust stream and increasing the positive charge of the ship will enhance the overall efficiency of the drives. Pure hydrogen is the universally preferred fuel for this purpose due to its abundance, ease of refinement, and high charge to mass ratio. Unlike Photonic/Tachyon Drives, however, Gravionic Drives require extra machinery to perform this function. These drives will not operate within Hyperspace. However, they are the only drives which do function within Subspace (see Subspace Jump Drives below). Reactionless Thruster Table (Gravionic Drives) TL10-12 TL Type Wt(lbs) Pwr(kws)Afterburner Fuel(GPH) Cost/lb 10 Std .05 .1 x5 .008H $50 11 HP .02 .1 x5 .008H $100 12 Adv .01 .05 x5 .004H $100 12 HP Adv .005 .05 x5 .004H $500 11+ Afterburner +25% +100% - - $200 Wt and Power are per pound of thrust. Cost is per pound of thrust. Afterburner is a multiplier to thrust efficiency when burning fuel. Afterburner: The afterburner adds 25% to final weight and doubles the drives power requirements. Volume(cf) is Wt/50. (*Note: Fuel is per pound of base thrust before afterburner modification.) Gravitic Drives: Gravitic drives are the ultimate reactionless thruster. They first appear at TL13 and enjoy some slight increases in efficiency at higher TL’s. Gravitic Drives provide acceleration by contracting space/time in front of the ship and expanding it abaft. This is typically accomplished by arranging the drive nodes in rings at the bow and stern of the craft. These Gravity Generator Nodes then form two balanced ‘bands’ of compressed space above and below the ship called the impeller wedge. By applying energy to this balanced system they then create a gradient within the system allowing the ship to ‘fall’ into the gravity well. This requires that power be applied continuously since as the ship slides into the imbalance, the whole system shifts with it until balance is restored. The impeller wedge requires energy to form it and maintain it in addition to the motive power requirements. If power is interrupted these ‘belly bands’ will quickly dissipate and will take time to reform. The time and energy required to form and maintain these bands depends on the maximum power potential of the drive system. The overhead power maintenance requirement is equal to twice the square root of the drive’s maximum power. The time required (in seconds) to form the impeller wedge is equal to the cube root of the drive’s maximum power in kW. The impeller wedge causes extreme localized gravitational stress. It is impossible to establish any deflectors or force screens covering the top, bottom, bow, or stern of an impeller equipped ship. Also, the DR of any ‘sidewall’ force screens cannot exceed twice the power required to maintain the impeller wedge (per side). On the brighter side, the impeller wedge provides DR equal to half the power (in Watts) required to maintain it, cubed! Realistically, nothing has ever been know to penetrate an impeller wedge, except for an impeller wedge of greater power (calculate damage from collisions substituting Impeller DR for HP with anything less than full penetration being ignored). In the event that an impeller wedge is penetrated, all Drive Nodes supporting it will overload and explode. All ships equipped with Gravitic Drives will require counter gravity compensators to isolate the ship’s internal frame of reference. As a rule, most ships only operate at 80% of capacity to avoid overloading the compensators. If the compensators are pushed to maximum capacity, roll once per minute for a failure. On a roll of 18 on three dice, the compensators fail, destroying the ship and killing the crew. Between 80% and 100% power, the chance of failure varies. Between 80% to 90% roll once every hour. If a failure is indicated, damage control gets ONE roll vs Engineering(Gravitics) to detect the problem. If they succeed, reduce the Malf number by one. If they fail, the compensators fail, as above. Between 90% and 95%, roll for failure once every ten minutes, decreasing the time between rolls by half for each percentile increase above 95% (maxing out at one per minute at 99%). Note that there is no chance for the ship’s engineers to detect the early warning signs of imminent compensator failure when operating above 90% of capacity. The greatest weakness of Gravitic Drives is Hyperspace. Gravity current phenomenon work under the exact same principles as impeller wedges. A ship with an active impeller wedge cannot enter a grav current. Treat this as a collision between the ship’s impeller wedge and an impeller wedge of infinite DR. The only hurdle over this obstacle are Warshawski Sails (see below). Reactionless Thruster Table (Gravitic Drives) TL13-15+ TL Type Wt(lbs) Pwr(kws) Cost/lb 13 Grav .001 .05 $4,000 14 Grav .00075 .05 $3,000 15+ Grav .0005 .05 $2,500 Wt and Power are per pound of thrust. Volume in cf is Wt/100. Hyperspace: Hyperspace is a region of space/time out of phase with normal space (N-space). The relationship is roughly similar to a comparison between the three dimensions of N-space and a two dimensional model. As an example, take a piece of paper. This represents a two dimensional world. Now curve the paper until the ends are almost touching. The paper is still representative of a two dimensional world, and there are no intrinsic experiments that a two dimensional being could perform to reveal his world as three dimensional. Any direction he travels on in his world will only reveal two dimensions. Now assume he invents a device which lets him travel into the third dimension. He still only experiences two dimensions, and all of his usual laws of physics still apply. But if he continues to travel in this third dimension, he will eventually come back into contact with his original two dimensional world. He never violated the laws of physics, but he experienced a change in physical coordinates well beyond the capabilities of his two dimensional world. Another good analogy would be to compare the relationship between N-space and Hyperspace to a basketball and a golf ball, respectively. Let’s assume that you can travel across the surface of the basketball (N-space) at a maximum velocity of 1cm per second. But you need to travel faster than this limit to get somewhere else. So you then translate your coordinates from the basket ball to the golf ball (Hyperspace) and continue to travel at your speed of 1cm per second. A few seconds later you have reached the opposite side of the golf ball and you translate you new coordinates to their corresponding coordinates on the basket ball. Safely back on your basket ball, you find that you are now at a point several times farther away than you would otherwise had been had you traveled across the surface of your basketball for the same time at that velocity. This relationship is the fundamental operating principle for a majority of so-called FTL drive systems. It is important to point out at this time that travel at or above the speed of light is impossible due to problems of energy density. FTL travel is not, in fact, faster than light. What it is, is travel within a dimensional coordinate set which is correspondingly smaller, or shorter, than our own N-space universe. Hyperspace is separated from N-space by a boundary region known alternately as Subspace, Otherspace, Nonspace, Subether, or Jumpspace. Beyond the Subspace boundary is Hyperspace. Subspace is a dimensional coordinate set without time and without measurable distance. Points within the Subspace coordinate set are differentiated only be particle mass/charge potential. Newtonian physics are meaningless there, while Einsteinian physics are merely irrelevant. Travel within Subspace requires extremely high energy densities. This is accomplished by imparting a very high positive charge to the hull of the ship. This is a simplified approximation, but gives a good description of Subspace nonetheless. Hyperspace, on the other hand, is very similar to our own Einsteinian universe with the exception that it is out of phase with the N-space universe. Space/time is extremely compressed and has been calculated at roughly 20,000:1 on average (one parsec in N-space correlating to ten AU in Hyper). Stellar objects found in N-space effect Hyperspace with a compressed gravity ‘shadow’. These shadows exhibit the tendency to amplify compression waves, creating ‘corridors’ of compressed gravity ‘currents’ much like currents in an ocean. This has the effect of energizing the Subspace boundary between Hyperspace and N-space, usually within thirty to one hundred light minutes of a stellar object. This is known as the Hyper Limit. It is impossible to translate into Hyperspace short of the Hyper Limit since the ship would impact the stellar system’s gravity shadow with fatal consequences. When these corridors continue uninterrupted from one star to another, they create what is known as a Jumpline. Sometimes these corridors have interruptions between stars, but otherwise form a straight route. These phenomenon are called Jump Points. They allow you to travel to more endpoints than Jumplines do, but are harder to access and navigate. Hyperdrive: Hyperdrive systems operate by translating your coordinate set to correlating coordinates within Hyperspace. They require enormous amounts of energy to open a "gate", and will only allow a certain amount of mass to transit the "gate" before the gate collapses. Once in Hyperspace, there are no further energy requirements to remain there. Exiting Hyperspace is the same as entering it, so Hyperdrives are normally designed to allow two "jumps" at a minimum. Military systems are routinely designed to initiate at least four jumps for tactical reasons. Many civilian ships and the smaller military ships do not mount Hyperdrives until TL12+. Instead they rely on "Jump Gates" to get them into and out of Hyperspace. Jump Gates are designed as free standing unmanned space stations capable of generating megaton capacity gates. Navigation between jumpgates is simplified by automatic piloting routines and only requires a Hyperspace Beacon Transceiver. Navigation is automatic with a successful Piloting (Hyperspace) roll. Navigation within Hyperspace must avoid gravitational "shadow" phenomenon. Collision with a grav wave is immediately fatal unless the ship is equipped with specialized drive systems which allow them to enter gravity currents. Travel within a grav wave is much faster than normal hyperspace travel, since space/time within a grav wave is contracted. This effect is discussed further under Warshawski Sails, below. Travel in Hyperspace is the same as it is in N-space. Distances traveled translate on a scale of roughly 20,000:1, allowing Hyperspace ships to traverse one parsec of N-space for every 10 AU of Hyperspace distance. Ships in Hyperspace will retain the same inertial frame of reference they had upon entering. This means that a ship capable of 1G acceleration will experience a pseudo acceleration effect of 20,000 G’s starting from their base velocity. As the ship approaches the speed of light, it will experience severe time dilation effects. The maximum velocity of light within Hyperspace is 6,000,000,000 kms relative to N-space. FTL Drives Table (Hyperdrive Systems) TL10-13+ TL Type Wt Power Cost Core Wt Core Cost 10 Hyperdrive 20 7.2GW $4,000 400 $40,000 11 Hyperdrive 15 4.8GW $3,000 200 $20,000 12 Hyperdrive 10 3.6GW $2,000 150 $15,000 13+Hyperdrive 7.5 1.2GW $5,000 40 $4,000 Wt, Power, Cost, Core Wt, and Core Cost are per ton of hypershunt capacity. Wt is in pounds. Volume is Wt/100 cf. Power is GWs per ton of hypershunt capacity to open the hypergate. Core Wt is the weight in pounds for an energy bank to store the power needed to open a gate. Figure the total core weight and multiply by the number of jumps desired. Note that the earlier drives will only be able to initiate a few jumps between recharges. Hyperdrive Rules: Astrogation (Hyperspace)/TL (M/H): Astrogation within Hyperspace requires a complete set of Hyperspace charts (200 Gigs/pc^3), and a computer running the Hyperspace Astrogation program calibrated for your ship. Plotting a course requires three rolls to fix starting position, ending position, and the course in between. The intent of this skill is to run least time transit calculations and vectors to avoid compression waves and gravity shadow phenomenon. While computers crunch the numbers, it is the astrogator’s job to anticipate the least time route. Otherwise the computer will chose the course it thinks best (safest not fastest). This skill is not likely to be learned outside of government service, either in the military or as an exploration scout. Calculating a course from scratch takes ten minutes for Hypershunt, one hour per parsec for course calculations, and thirty minutes for N-space shunt. Hyperspace Astrogation program (Complexity 9 $54,000,000) Hyperspace Chart Database ($5,000 200Gig)x pc^3 Hyperspace Beacon Transceiver ($250,000 200 lbs 4cf 1kw) (Note: These prices are all at TL10. Prices drop normally for higher TL’s) Warshawski Sails: Warshawski Sails are an adjunct to Gravitic Drives. They do not appear until mid to late TL13. They were designed to allow Gravitic Drive ships to utilize grav waves in Hyperspace. They work by reconfiguring the impeller wedge from dorsal and ventral bands into fore and aft gravity ‘sails’. With the Warshawski Sails configured, the ship can then safely enter a grav wave and ride it to its destination in much the same manner as a cable car operates. To use Warshawski Sails, a ship must first have a Gravitic Drive. One half of its impeller nodes are then modified to focus the Warshawski Sails. These nodes are referred to as Alpha nodes, and are placed in two rings, one fore and one aft. The Beta nodes form separate rings immediately interior to the Alpha rings. The Alpha nodes then focus the sails. Due to the compression wave disturbances created by Warshawski Sails, it is impossible to use sidewall generators with the sails deployed. Although not as fast as Jump drives, Warshawski Sail ships can use grav waves in deep space that have no corresponding jump points. This allows them to transit distances much faster than any other ships in Hyperspace. Acceleration within a grav wave are equal to the ship’s nominal acceleration multiplied by the square root of the drives maximum power (in kw). FTL Drive Table (Warshawski Sails)TL13+ TL Type Weight Cost 13+ Alpha Node Generators +50% +100% All Warshawski Sails increase the total mass/volume of the Gravitic Drive system by 50% and double the cost. There are no further energy requirements. This is the gravitic hyperdimensional equivalent to vectored thrust. Jumpline Drives: Jumpline drives are the most simplistic, and most limited, form of FTL drive. They take advantage of the weakened threshold between N-space and Hyperspace caused by Hyperspace grav currents (Jump Lines). By applying power to these weak boundaries, the Jumpline Drive ship jumps into the heart of the grav wave. Jumpline transit times are extraordinarily short as space/time is compressed by a factor of 3.535E24. Since jumplines only connect to a single destination, astrogation is ludicrously simple. Only minor calculations are needed to intercept the jump point on the correct vector. Initiating a Jump is a simple matter of energizing the Jump Grid built into the hull of the ship at the exact moment the ship intercepts the jump point. The ship then follows the pre-calculated course to its endpoint. Setting up for a Jump requires a successful Astrogation(N-space) roll and a successful Piloting roll (both necessary to be in the right place at the right time with the correct base velocity while energizing the grid at the right instant). Jumpline origin points are typically located between 30 and 100 light minutes from a given primary. Therefore it is necessary for a Jumpline Drive ship to have some form of propulsion to move around within a planetary system. Jumpline transit times are effectively instantaneous. FTL Drive Table (Jumpline Drives)TL10-12 TL Type Wt Power Cost Grid Wt Grid Cost 10 Jumpline Drive 25 360MW $400 .25 $1,500 11 Jumpline Drive 12 360MW $400 .15 $1,000 12 Jumpline Drive 4 360MW $80 .1 $250 Wt, Power, and Cost are per ton of Jump Mass. Grid Wt and Grid Cost are per sf of hull surface area for the jump grid. Jumpline Drive Rules: Astrogation(Jumpline)/TL (M/A): Calculations require simple star charts, and an astrogation program. These take about five minutes to calculate. The greatest factor in setting up for a jump is approaching the Jumpline origin on the correct vector. Failure has absolutely no effect. The energy is discharged, but the ship fails to jump. Most astrogators usually spend an hour or more rechecking their calculations, just to be on the safe side. Jumpline Astrogation (Complexity 4 $20,000) Jumpline Star Charts (1 Gig/AU^3 $500) Jump Point Drive: Jumppoint Drives are similar to Jumpline drives, and can use the same Jumplines at the power requirements listed for those drives. They can also utilize Jump Points which do not have a corresponding linear connection to another Jump Point as Jumplines do. Jump Point Drives are also instantaneous, like Jumpline Drives, but are much more versatile. Astrogation through a Jump Point is a simple 3-D calculation that can be preprogrammed (or purchased) and is invariant for a given course. Calculating a Jump manually (with a computer) requires simple Hyperspace charts, a complexity 6 computer (or better) and about one hour per parsec of jump distance. Initiating a Jump is a simple matter of energizing the Jump Grid built into the hull of the ship at the exact moment the ship intercepts the jump point. The ship then follows the pre-calculated course to its endpoint. Setting up for a Jump requires a successful Astrogation(N-space) roll and a successful Piloting roll (both necessary to be in the right place at the right time with the correct base velocity while energizing the grid at the right instant). FTL Drive Table (Jump Point Drives)TL10-12 TL Type Wt Power Cost Grid Wt Grid Cost 10 Jump Point Drive 30 720MW $900 .50 $3,000 11 Jump Point Drive 15 720MW $500 .30 $2,000 12 Jump Point Drive 8 720MW $250 .20 $500 Wt, Power, and Cost are per ton of Jump mass. Grid Wt and Grid Cost are per sf of hull surface area for the jump grid. Jump Point Rules: Astrogation (Jump Point)TL (M/A): The skill used to successfully calculate a Jump course through Jump Points. Pre-requisite: Astrogation(N-space), Mathematics Jump Point Astrogation (Complexity 6 $120,000) Jump Point Star Charts (10 Gig/pc^3 $2,000) Subspace Jump Drive: The Subspace Jump Drive is the fastest, most versatile Jump Drive possible. Instead of jumping through the Subspace boundary into Hyperspace, the Subspace Jump Drive translates the ship into the boundary for the duration of the Jump. Without a Gravionic Drive, this drive system is virtually useless (see Stutter Warp, below). Subspace Jump Drives differ from all other FTL drive systems because of their fuel requirements. This is because Subspace lacks certain dimensional definitions which would allow Newtonian physics to operate. The fuel is expelled prior to jump to increase the energy potential of the ship which then translates into a change of physical location in N-space at the end of the jump. Astrogation requires complex 3-D calculations to be made immediately before the jump. These calculations take ten minutes per parsec, assuming the astrogator has a full set of star charts. FTL Drive Table (Jump Drive)TL10-13+ TL Type Range Wt Pwr Fuel Cost Grid Wt Grid Cost 10 Jump Drive 1 pc 1.0 5 .67 $25 .15 $1,000 10 Jump Drive 2 pc 1.5 10 1.34 $50 .15 $1,000 11 Jump Drive 3 pc 2.0 15 2 $30 .10 $800 11 Jump Drive 4 pc 2.5 20 2.67 $60 .10 $800 12 Jump Drive 5 pc 3.0 25 3.34 $40 .06 $500 13+ Jump Drive 6 pc 3.5 30 4 $50 .04 $1,000 Wt, Power, Fuel, and Cost are per cf of volume to be jumped. Grid Wt, and Grid Cost are per sf of hull surface area for the Lanthanum grid. Range: Drives Maximum range in parsecs. Wt: Weight in pounds per cf of volume. Power: Power in kW per cf of volume. Fuel: Gallons of hydrogen per cf of volume for maximum jump range. Shorter jumps use proportionally less fuel. Cost: Cost per cf of volume. Subspace Jump Rules: Astrogation(Subspace)/TL (M/H): Jump calculations can only be made immediately before a jump. Any delay means the calculations need to be redone. This requires the appropriate astrogation program and the correct star charts. Subspace Astrogation (Complexity 8 $300,000) Subspace Astrogation Charts (20 Gig/pc^3 $5,000) Drop Tanks: Many ships require more fuel than they can carry to initiate a jump. In these cases, they can carry external fuel tanks which are jettisoned immediately prior to jump. Drop tanks are $6(new) or $2(used) and 1.08 lbs per gallon of capacity. They are commonly available in standard sizes. Retailers will recover empty tanks (and any unused fuel), and tend to add beacons to facilitate recovery. The ramifications of this are that civilian freighters will be big fat obvious targets as they boost out to the Jump Point, a weakness which most pirates exploit. Stutterwarp Drive: Stutterwarp Drives are nearly identical in operation to Subspace Jump Drives, but assume that Gravionic Drives have not been invented. Without Gravionic propulsion the ship will only jump a very short distance based on the energy of the jump field and the mass being jumped. This typically works out to a distance between a few hundred meters and several kilometers. But by maintaining the hull grid charge and cycling the jump at high frequencies, pseudo-FTL velocities can be achieved. Stutterwarp Drives are rated for their power level and drive coefficient. Warp efficiency is equal to (P/M)^1/3*N, where P equals the drive power in MW-h, M is the ship’s mass in tons and N is the drive coefficient. The Warp Efficiency is equal to light years per day of travel in deep space. This efficiency breaks down at the hyper limit (generally 30 to 100 AU from a stellar primary) where local gravity exceeds .0001G. Within the hyper limit, Stutter Warp Drive velocity is 310miles/sec (500kms) times the Warp Efficiency. Stutterwarp drives suffer a further breakdown within .1G where their pseudo velocity cannot overcome local gravitational pull, so Stutterwarp ships will need conventional thrusters capable of orbital maneuvering. Another limitation of Stutterwarp Drives is their range. As a Stutterwarp Drive is used, it builds up a charge within its hypershunt coils. Discharging this build up requires minor mechanical work and up to 40 hours within a strong gravity well (around .01G or greater). If this energy is not discharged before the ship travels 7.7 light years, the charge build up exceeds the maximum energy density of the coils and spontaneously releases with catastrophic results. However, multiple drives can be used in series to extend range by switching to a ‘fresh’ drive unit as the current one reaches its threshold. FTL Drive Table (Stutterwarp Drive)TL9-11 TL Type Mass Volume Variable(N) Cost 9 Stutterwarp N(P^1/3) Wt/100 14.50 $1M 10 Stutterwarp N(P^1/3) Wt/90 16.05 $1M 11 Stutterwarp N(P^1/3) Wt/85 17.50 $1M 12 Stutterwarp N(P^1/3) Wt/75 19.05 $1M Mass: This is the drive’s mass in tons Volume: Volume in cf equals weight in pounds divided by the number on the table. Variable: This is the Drive coefficient used for the Warp Efficiency calculation. Cost: is the cost per ton at the TL of introduction. This is reduced by half at the next TL, and halved again two TL’s higher. Stutterwarp Rules: Astrogation (Stutterwarp)/TL (M/A): Stutterwarp astrogation is very simple. It only requires a simple star chart of local space and follows a modified straight line approach. Stutterwarp Astrogation (Complexity 2 $4,000) Stutterwarp Astrogation Charts (1 Gig/pc^3 $100) Warp Drive: Warp Drives are the antithesis of Subspace Jump Drives. Instead of surrounding the ship with a bubble of N-space and traveling through Subspace, the Warp Drive surrounds itself with a bubble of Subspace and travels through N-space. The net effect is to adopt a universal frame of reference so that truly faster than light speeds may be achieved. Warp ships can stop in an instant, and change direction freely at any speed. A Warp Ship’s maximum superluminary velocity is equal to its Warp Thrust Factor (WTF) divided by its mass in tons. This equals the ship’s speed in parsecs per day. FTL Drive Table (Warp Drive)TL10-15+ TL Type Wt Power Cost 10 Warp Drive 4,000+(100xWTF) 100kWxWTF $20,000+($500xWTF) 11 Improved Warp Drive 2,000+(50xWTF) 100kWxWTF $20,000+($500xWTF) 12 Improved Warp Drive 2,000+(50xWTF) 100kWxWTF $20,000+($50xWTF) 13 Adv Warp Drive 1,000+(25xWTF) 75kWxWTF $2,000+($50xWTF) 14 Adv Warp Drive 1,000+(25xWTF) 75kWxWTF $2,000+($25xWTF) 15+ Compact Warp Drive 250+(5xWTF) 50kWxWTF $1,000+($50xWTF) WTF is the FTL thrust potential of the drive unit. Warp Drive Rules: Astrogation(Warp Drive)/TL (M/E): Calculations are child’s play. Even a high school kid could plot a course. Just ask Wesley Crusher... Of course, the computer does all of the work. Warp Astrogation Program (Complexity 4 $24,000) Warp Astrogation Star Charts (10 Gig/pc^3 $100) John "A head shot means you're serious" Fosgett "Honor is irrelevant." -Ambassador Kosh, Bablyon 5