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Post by The Astronomer on May 28, 2017 14:18:15 GMT
The word "missile" is a bit misguiding in this place. the Torch missile will weigh between 25 and 50 tons. having multiple tons of payload, most likely casaba howitzers. This is a very extreme case of torch missile designed to cover one Astronomical unit in under 24 hours. That's like 50G, the electronics in the Exacto Smart bullet can survive accelerations of 40 thousand G. This missile is hypothetical far future missile, in a setting where Torch drives like orion are commonplace. I am currently not interested on how fast I can make a CoaDE missile. Anything better than NTR seems to never hit something. My current design has only a dry acceleration of 41G. convertalot.com/relativistic_star_ship_calculator.htmlHave fun. If you're going fast, both exhaust velocity and thrust will be need. Due to the high power required, the engine will end up being absurdly large to dissipate the heat. Guess what happen when your engine got shot. Alternatively, try a beam core, which requires immense power.
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Post by Kerr on May 28, 2017 14:35:10 GMT
The word "missile" is a bit misguiding in this place. the Torch missile will weigh between 25 and 50 tons. having multiple tons of payload, most likely casaba howitzers. This is a very extreme case of torch missile designed to cover one Astronomical unit in under 24 hours. That's like 50G, the electronics in the Exacto Smart bullet can survive accelerations of 40 thousand G. This missile is hypothetical far future missile, in a setting where Torch drives like orion are commonplace. I am currently not interested on how fast I can make a CoaDE missile. Anything better than NTR seems to never hit something. My current design has only a dry acceleration of 41G. convertalot.com/relativistic_star_ship_calculator.htmlHave fun. If you're going fast, both exhaust velocity and thrust will be need. Due to the high power required, the engine will end up being absurdly large to dissipate the heat. Guess what happen when your engine got shot. Alternatively, try a beam core, which requires immense power. I mainly focused on propulsion methods which don't require a power source at all or only a small one. (Orion, ACMF, AMBC, NSWR) For what reason did you send me that online calculator? It's only useful if you consider a constant acceleration.
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Post by Enderminion on May 29, 2017 17:20:36 GMT
you might try a Medusa Drive?
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Post by Kerr on May 29, 2017 19:35:18 GMT
you might try a Medusa Drive? Yes, that was option 1b. Orion-style B: Warheads: Pusher plate: Sail Yield: 10kT Sail material: 3D-Graphene Mass: 1kg Area:8,33km² Type: Antimatter Catalyzed (1µg) Wet mass: 25t Dry mass: 15t Payload: 3t Electronics and radiators etc.: 2t Engine mass: 10t (5t Antimatter storage, 4t Sail, 500kg Antimatter+Fusion fuel injector. Achieving 400-600 ks impulse might be very well achievable.
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Post by RiftandRend on May 30, 2017 0:29:04 GMT
Does anyone have other ideas except Fusion drives? They are just too massive for use, they require giant apparatuses to start a fusion reaction. Antimatter initiated fusion might be what you're looking for. Relatively low power requirement and good performance.
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Post by The Astronomer on May 30, 2017 12:05:07 GMT
You might want to stick to NSWR if your scenario has no reliable amat production capability. Once you get that covered, go amat-fusion.
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Post by Kerr on May 30, 2017 13:42:24 GMT
You might want to stick to NSWR if your scenario has no reliable amateur production capability. Once you get that covered, go amat-fusion. The long-range strategic torch missiles is supposed to be a counter-weapon in a scenario where Advanced Orion drives (AM Fusion, Medusa, Z-pinch) are commonplace. Basically, the missile will scale with the warships, always being on par with them. Question: Is 9Mm/s exhaust velocity realistic for fusion pulse units? Considering Orion MAX (Pure fusion),IC-Fusion and the Firefly (Z-pinch) reach 10-13Mm/s? The effective exhaust is 4,5Mm/s (Huh, it's actually worse than 90% NSWR at this moment, but there's room for improvement).
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Post by Enderminion on May 30, 2017 14:11:52 GMT
You might want to stick to NSWR if your scenario has no reliable amateur antimatter production capability. Once you get that covered, go amat-fusion. do not buy antimatter at the lowest price, you are asking for Murphy.
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Post by The Astronomer on May 30, 2017 14:33:01 GMT
You might want to stick to NSWR if your scenario has no reliable amateur antimatter production capability. Once you get that covered, go amat-fusion. do not buy antimatter at the lowest price, you are asking for Murphy. amateur antimatterYou know, THAT AUTOCORRECT. Fixed though.
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Post by matterbeam on May 30, 2017 16:21:36 GMT
Some thoughts: 20% NSWR might be too large to fit inside your 10 ton limit because its exhaust velocity is too low and you need a lot of water in one place to initiate a reaction. Uranium is 19.1g/cm3, water is 1g/cm3, so you'd need about 96x the water to uranium ratio in volume in the nozzle to ignite the reaction. Incomplete control over the flow means you'd be wasting uranium salt around the reaction point, so you'd need maybe even more water. The solution to smaller NSWRs is to increase the uranium concentration. The problem with this is that, for example, at 90% uranium, a tiny wave caused by vibrations or a stray impact can increase the concentration locally to 100% and blow the whole thing up. Orion-style fission is an inefficient use of nuclear energy if your payload is also nuclear warheads... fusion requires large ignition facilities... but you can combine them with the concept of laser ablative propulsion and create an externally-powered inertial confinement drive. The propellant pellet is heated by a laser pulse. It expands at the root mean square velocity of its gasses and the laser:kinetic conversion can be 90% efficient or higher (achieved in laboratory). Here's a calculator for how fast the gasses go: calistry.org/calculate/kineticTheoryVelocityCalculator. You are limited, however, but the laser energy. If the pellet contains fusion fuel, and you can very accurately shape the laser pulse, you can compress it enough to ignite fusion. Your megajoule-scale pulses can release gigajoules of energy or more. If the requirements for laser ignition sound too tricky, complex or too powerful, you can instead use mini-mag orion. An electromagnetic pulse compressed a small fission pellet (maybe with fusion booster) to ignite a nuclear reaction. The power requirements are very small.
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Post by Kerr on May 30, 2017 17:04:55 GMT
Some thoughts: 20% NSWR might be too large to fit inside your 10 ton limit because its exhaust velocity is too low and you need a lot of water in one place to initiate a reaction. Uranium is 19.1g/cm3, water is 1g/cm3, so you'd need about 96x the water to uranium ratio in volume in the nozzle to ignite the reaction. Incomplete control over the flow means you'd be wasting uranium salt around the reaction point, so you'd need maybe even more water. The solution to smaller NSWRs is to increase the uranium concentration. The problem with this is that, for example, at 90% uranium, a tiny wave caused by vibrations or a stray impact can increase the concentration locally to 100% and blow the whole thing up. Orion-style fission is an inefficient use of nuclear energy if your payload is also nuclear warheads... fusion requires large ignition facilities... but you can combine them with the concept of laser ablative propulsion and create an externally-powered inertial confinement drive. The propellant pellet is heated by a laser pulse. It expands at the root mean square velocity of its gasses and the laser:kinetic conversion can be 90% efficient or higher (achieved in laboratory). Here's a calculator for how fast the gasses go: calistry.org/calculate/kineticTheoryVelocityCalculator. You are limited, however, but the laser energy. If the pellet contains fusion fuel, and you can very accurately shape the laser pulse, you can compress it enough to ignite fusion. Your megajoule-scale pulses can release gigajoules of energy or more. If the requirements for laser ignition sound too tricky, complex or too powerful, you can instead use mini-mag orion. An electromagnetic pulse compressed a small fission pellet (maybe with fusion booster) to ignite a nuclear reaction. The power requirements are very small. My idea of igniting the pellets was using antimatter, several documents mentioned that 1µg antimatter is sufficient to ignite fusion, which then can sustain further fusion. Carrying a total of 10 metric tons of LiD/DT/etc. and 10 milligram of antimatter, the pellet is shot in the direction of sail, the cryogenic antimatter is ionized with a laser pulse and then accelerated in the direction of the LiD ball. Considering a 10kT/1kg ball which will expand at 9,48Mm/s with a effective exhaust velocity of 4,5Mm/s and 4,5MN thrust (50% of the energy is gonna be lost) (using Nuclear propulsion units might increase energy efficiency but heavily decrease mass efficiency.) After 2h and 46 minutes the torch missile will reaches its final velocity of 2400km/s. With either 1x 1MT NEFP, 16x 1MT Casaba Howitzers or 100x 1kT NEFP as a payload. The NEFP get a 15x increase in kinetic energy through the missile. And the Casaba 50% KE and 25% range increase. The Laser Plasma pulse design will find use in smaller missiles. Considering the terawatt laser thread, and the small calculation I did on "Inaccurate Laser damage" mainly: the lasers will output 54,6 metric tons of tnt per second, sufficient to consider a fusion drive. but even in a realistic scenario where laser warships have much lower output this method of propulsion is still a very likely candidate. The Z-pinch method seemed too weak for my purposes, but it may result in a near-time variant of this monstrosity of a torch missile. Is there a thermal kinetic ratio for pure fusion explosions? So I can get a better estimation for the exhaust vel. and thrust.
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Post by matterbeam on May 30, 2017 22:04:06 GMT
Some thoughts: 20% NSWR might be too large to fit inside your 10 ton limit because its exhaust velocity is too low and you need a lot of water in one place to initiate a reaction. Uranium is 19.1g/cm3, water is 1g/cm3, so you'd need about 96x the water to uranium ratio in volume in the nozzle to ignite the reaction. Incomplete control over the flow means you'd be wasting uranium salt around the reaction point, so you'd need maybe even more water. The solution to smaller NSWRs is to increase the uranium concentration. The problem with this is that, for example, at 90% uranium, a tiny wave caused by vibrations or a stray impact can increase the concentration locally to 100% and blow the whole thing up. Orion-style fission is an inefficient use of nuclear energy if your payload is also nuclear warheads... fusion requires large ignition facilities... but you can combine them with the concept of laser ablative propulsion and create an externally-powered inertial confinement drive. The propellant pellet is heated by a laser pulse. It expands at the root mean square velocity of its gasses and the laser:kinetic conversion can be 90% efficient or higher (achieved in laboratory). Here's a calculator for how fast the gasses go: calistry.org/calculate/kineticTheoryVelocityCalculator. You are limited, however, but the laser energy. If the pellet contains fusion fuel, and you can very accurately shape the laser pulse, you can compress it enough to ignite fusion. Your megajoule-scale pulses can release gigajoules of energy or more. If the requirements for laser ignition sound too tricky, complex or too powerful, you can instead use mini-mag orion. An electromagnetic pulse compressed a small fission pellet (maybe with fusion booster) to ignite a nuclear reaction. The power requirements are very small. My idea of igniting the pellets was using antimatter, several documents mentioned that 1µg antimatter is sufficient to ignite fusion, which then can sustain further fusion. Carrying a total of 10 metric tons of LiD/DT/etc. and 10 milligram of antimatter, the pellet is shot in the direction of sail, the cryogenic antimatter is ionized with a laser pulse and then accelerated in the direction of the LiD ball. Considering a 10kT/1kg ball which will expand at 9,48Mm/s with a effective exhaust velocity of 4,5Mm/s and 4,5MN thrust (50% of the energy is gonna be lost) (using Nuclear propulsion units might increase energy efficiency but heavily decrease mass efficiency.) After 2h and 46 minutes the torch missile will reaches its final velocity of 2400km/s. With either 1x 1MT NEFP, 16x 1MT Casaba Howitzers or 100x 1kT NEFP as a payload. The NEFP get a 15x increase in kinetic energy through the missile. And the Casaba 50% KE and 25% range increase. The Laser Plasma pulse design will find use in smaller missiles. Considering the terawatt laser thread, and the small calculation I did on "Inaccurate Laser damage" mainly: the lasers will output 54,6 metric tons of tnt per second, sufficient to consider a fusion drive. but even in a realistic scenario where laser warships have much lower output this method of propulsion is still a very likely candidate. The Z-pinch method seemed too weak for my purposes, but it may result in a near-time variant of this monstrosity of a torch missile. Is there a thermal kinetic ratio for pure fusion explosions? So I can get a better estimation for the exhaust vel. and thrust. A small sphere of superheated plasma expanding inside a 'bird cage' style magnetic nozzle converts 80% or better of its energy into the spaceship's kinetic energy. This because it expands in three dimensions and six axis: the kinetic theory of gasses state that as it expands, it cools. If it cools, then the thermal energy is being converted into kinetic energy of the particles. This is the effect you see in deLaval nozzles. At 10kT/1kg, you are certain to have 100% ionization of the reaction products. Nothing will slip through the magnetic field. The problem then becomes providing a magnetic field strong enough to deflect all the particles without being pushed out of the way are basically ignored by nearly relativistic particles.
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Post by Kerr on May 31, 2017 5:07:15 GMT
My idea of igniting the pellets was using antimatter, several documents mentioned that 1µg antimatter is sufficient to ignite fusion, which then can sustain further fusion. Carrying a total of 10 metric tons of LiD/DT/etc. and 10 milligram of antimatter, the pellet is shot in the direction of sail, the cryogenic antimatter is ionized with a laser pulse and then accelerated in the direction of the LiD ball. Considering a 10kT/1kg ball which will expand at 9,48Mm/s with a effective exhaust velocity of 4,5Mm/s and 4,5MN thrust (50% of the energy is gonna be lost) (using Nuclear propulsion units might increase energy efficiency but heavily decrease mass efficiency.) After 2h and 46 minutes the torch missile will reaches its final velocity of 2400km/s. With either 1x 1MT NEFP, 16x 1MT Casaba Howitzers or 100x 1kT NEFP as a payload. The NEFP get a 15x increase in kinetic energy through the missile. And the Casaba 50% KE and 25% range increase. The Laser Plasma pulse design will find use in smaller missiles. Considering the terawatt laser thread, and the small calculation I did on "Inaccurate Laser damage" mainly: the lasers will output 54,6 metric tons of tnt per second, sufficient to consider a fusion drive. but even in a realistic scenario where laser warships have much lower output this method of propulsion is still a very likely candidate. The Z-pinch method seemed too weak for my purposes, but it may result in a near-time variant of this monstrosity of a torch missile. Is there a thermal kinetic ratio for pure fusion explosions? So I can get a better estimation for the exhaust vel. and thrust. A small sphere of superheated plasma expanding inside a 'bird cage' style magnetic nozzle converts 80% or better of its energy into the spaceship's kinetic energy. This because it expands in three dimensions and six axis: the kinetic theory of gasses state that as it expands, it cools. If it cools, then the thermal energy is being converted into kinetic energy of the particles. This is the effect you see in deLaval nozzles. At 10kT/1kg, you are certain to have 100% ionization of the reaction products. Nothing will slip through the magnetic field. The problem then becomes providing a magnetic field strong enough to deflect all the particles without being pushed out of the way are basically ignored by nearly relativistic particles. That's why I choose a Medusa design, a magnetic nozzle might heavily increase energy efficiency, but it would mean that I have to reduce the mass flow to gram scale, and that would mean that I'd need several hundred times longer to reach a desired velocity of 2,4Mm/s. Also, how would I power such a magnetic nozzle? I had to add a reactor and radiators adding further complexity and mass to the missile.
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Post by nerd1000 on May 31, 2017 9:41:11 GMT
A small sphere of superheated plasma expanding inside a 'bird cage' style magnetic nozzle converts 80% or better of its energy into the spaceship's kinetic energy. This because it expands in three dimensions and six axis: the kinetic theory of gasses state that as it expands, it cools. If it cools, then the thermal energy is being converted into kinetic energy of the particles. This is the effect you see in deLaval nozzles. At 10kT/1kg, you are certain to have 100% ionization of the reaction products. Nothing will slip through the magnetic field. The problem then becomes providing a magnetic field strong enough to deflect all the particles without being pushed out of the way are basically ignored by nearly relativistic particles. That's why I choose a Medusa design, a magnetic nozzle might heavily increase energy efficiency, but it would mean that I have to reduce the mass flow to gram scale, and that would mean that I'd need several hundred times longer to reach a desired velocity of 2,4Mm/s. Also, how would I power such a magnetic nozzle? I had to add a reactor and radiators adding further complexity and mass to the missile. If you're using beamed laser power to heat the reaction mass it should be easy enough to power the magnetic nozzle with energy harvested from the laser beam. Just add a ring of solar panels (tuned for your laser wavelength) around the drive and defocus the beam a little bit so some of the energy hits them. A small increase in beam power should be enough to provide all the extra energy you need, and the panels should be much lighter and cheaper than an on-board reactor and radiators.
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Post by Kerr on May 31, 2017 12:26:50 GMT
That's why I choose a Medusa design, a magnetic nozzle might heavily increase energy efficiency, but it would mean that I have to reduce the mass flow to gram scale, and that would mean that I'd need several hundred times longer to reach a desired velocity of 2,4Mm/s. Also, how would I power such a magnetic nozzle? I had to add a reactor and radiators adding further complexity and mass to the missile. If you're using beamed laser power to heat the reaction mass it should be easy enough to power the magnetic nozzle with energy harvested from the laser beam. Just add a ring of solar panels (tuned for your laser wavelength) around the drive and defocus the beam a little bit so some of the energy hits them. A small increase in beam power should be enough to provide all the extra energy you need, and the panels should be much lighter and cheaper than an on-board reactor and radiators. This is good idea for my SRTM [1], but not so much for my LRSM [2] 1. Even with a magnetic nozzle I am still limited to gram scale mass flows 2. I'd need a laser that can ignite 10kT fusion charges at 0-12 million kilometers distance. You could use giant mirror but this creates more problems. [1] SRTM: Short range tactical missile. Using Laser Pulse propulsion (LPP) Dv: 100-800km/s [2] LRSM: Long range strategic missile. Using AM catalyzed fusion (AMCF) in a medusa design. Dv: 2-3Mm/s
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