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Nuclear Fusion Pulse Rocket The alien
xenosophont race known as the Cybyota continue to use fusion-pulse
vessels for interplanetary and interstellar journeys;
small fusion devices are detonated behind the shield at the rear of the vessel, and propel the ship during the acceleration phase |
| Nuclear Fusion Pulse Rocket - Data Panel
Summary: The Fusion Pulse drive uses small fusion bomblets which are serially detonated within the combustion chamber to produce a more or less smooth thrust. There are two types, the basic lo tech "dumb" or inert model which uses a physical pusher plate and does not require sentient ai, and the high performance hi tech "smart" model which requires advanced ai to coordinate the bomblets and the magnetic "pusher plate" See also Fusion Basic Propulsion: Reaction Specific Impulse [sec]: lo tech: 10,000 to 35,000 hi tech: 105 to 106 Fuel: Deuterium or He3 pellets Reaction Mass: as above Minimum Technology Required: lo tech: Microtech, Nanocomposites hi tech: Nanocomposites, Precision Nanotech, Sentient AI Matter Manipulation: microscale/nanoscale (precision materials) Controller required: lo tech: advanced non-sentient computers hi tech: sentient ai First Introduced: lo tech: Late Information Age hi tech: Middle Interplanetary Age Used by: lo tech: mostly historical hobbyists, possibly a few isolated ludd or anti-ai groups hi tech: Many polities, clades, individuals and groups away from the Nexus, in low resource solar systems and among members of the Deeper Covenant, out on the periphery, and among some anti-ai luddite groups Used in: medium to high speed interplanetary and near-interstellar transport; generally impractical for true interstellar transport, although still used by some deep oort haloist groups Construction Costs: lo tech: Autofac: medium (bulky, precision materials); Hylonano: reasonably cheap assuming presence of component materials hi tech: Autofac: high (bulky, precision materials, requires exporting of some parts); Hylonano: somewhat expensive, requires presence of component materials. Requires trained and dedicated ai (generally turingrade or superturingrade) Running cost: depends on availability of fuel Advantages: reliable (lo tech), good performance (hi tech), reasonably easy fuel storage, can be made with materials in most solar systems, does not require amat Disadvantages: insufficient isp for decent interstellar transport, unstealthy, produces radioactive exhaust Normal Acceleration: lo tech: 0.01 to 0.1 g hi tech: 0.05 to >1 g Normal Top/Cruising Speed lo tech: 50 - 100 km/sec hi tech: 50 km/sec to 0.1 c (depending on design and fuel availability) |
The nuclear fusion-pulse rocket is powered by continuous explosions of small amounts of nuclear fusion material, and propelled by deflecting the explosive forces with reflectors. Depending on ship design and pellet size, up to 200 explosions may occur every minute. Either deuterium or He3 pellets can be used; detonation is by intense electron beam or laser burst. Alternatively amat can be used to trigger detonation, which gives a slightly better performance. Such a drive is somewhat like riding on a continuous stream of mini-nukes, equivalent to a 10kt bomb every second; the power output is in the regions of tens of terawatts. The exhaust velocity is as much as 6000 km s-1, and the drive plume is highly dangerous out to a distance of tens of thousands of kilometres. Such systems are only reasonable for operations well away from planets or habitats; indeed the drive is of considerable use as a weapon. A ship using a fusion drive is also extremely unstealthy, and will be easily visible on the far side of the system.
Fusion pulse came into its own with the mass-production of ultra-light ultrastrong materials like Buckyfibre and other forms of Diamondoid, during the middle and late Interplanetary age. These much more advanced ships had pulse repetition rates of several hundreds per second, and replaced the heavy ceramic-carbon-metal composite pusher-plate for a powerful magnetic field, which channelled the charged particles into an exhaust. Converging laser or electron beams ignited the pellets by compressing and confining the fuel, with some of the energy released being used to power the beams and the magnetic fields. The tweak societies and some megacorps of the later interplanetary age often favoured this type of drive, and it still remains in use with a large number of clades and groups today away from the main nexus
Today, Fusion Pulse, like continuous Fusion drive, is a cheap and robust, relatively low tech system that does not require advanced AI piloting, and hence is widely used by a number of bioist, anthropist, and human supremacist clades and factions throughout the galaxy. While grossly inefficient and expensive as a star drive (even good sub-relativistic velocities are virtually impossible, due to the huge amount of reaction mass that would be required), they serve very well as a standard interplanetary vessel, especially in systems rich in He3.
