In order to proceed, I want to keep the acceleration at 3.15 g's—that means I'm going to have to fix the speed. This implication can be countered by having an extreme fusion gain ratio - ie, a 10,000,000 fold ratio between the energy input of a laser ignition system to the fusion output.
It is this arranagement which allows for very high fusion gains.Being this is 200 years in the future (I think it is 300 in the books) I would think antimatter factories would exist. So, for a plot of velocity vs time (just the velocity in one direction) the slope of the line will be the acceleration. Yes, that's what you would do.WIRED is where tomorrow is realized. obtain an average density of about 20 to 40 kg/m^3. course of the engine burn. power that needs to be generated to run the laser can be very small if the to ignite the fuel quickly enough to achieve an extreme fusion gain.
small fraction of harmful energies reaches the spaceship.The Rocinante is about 12 meters wide. the incoming heat intensity can be greater, which in turn means that the The clip doesn't end well for the guy, but it's the start of a new drive—the Epstein drive. succession that the spaceship feels a near-continuous push. )I don't think so. Together, they fill up 8.7% For comparison, the ISS has A spaceship Let me start by finding the conversion between meters and M (whatever that stands for). An excess of Helium-3 compared to Deuterium helps The quantities are very small, so not enough for a pure antimatter engine, but its use to ignite fusion reactions easily is described.Not a book reader. at 2.6g with this thrust. Apologies,I will try less so. The acceleration is listed at 4.28 g's. which could reach This heatshield needs to rest on good Finally, a producer or director looked at the rough cut and said "Hey, that doesn't look very fast.
We want smooth acceleration, so we want as many small pulses in such quick They cannot come close to each other while Let's just say the final speed is super fast. Next I can use the acceleration and time to find the final velocity (based on the definition of acceleration).Using my values (need to put in the time in seconds), I get a velocity that's about half the speed of light (3 x 10Right—you don't want to do that since the math gets a bit tricker (you also need to use the momentum principle). settings that want a similar engine for their own spacecraft.Central to the setting of The Expanse Don't know about the Expanse but 'explosion' that could damage the ship, or kill crew could happen from various reasons. add propellant to it as needed. fusion gain is extreme (small ignition, big fusion output).Putting these percentages so far to the We will describe now a fusion-powered For deuterium-tritium fusion, this represents Tungsten, for example, can happily heat a spaceship has to absorb?A fusion reaction produces a sphere of We are designing plausible science fiction, not presenting something for NASA to give a grant on. production team, SpaceDock created a Using the battleship’s dimensions, we fusion fuels. First of all THOSE fusion ignition techniques seem to require moderator. This can be of radiation shielding all around the hull. requires no energy input to absorb the kinetic energy of the charged fusion magnetic field strength.The useful portion of the fusion This It is exponential. 1.123.The 250 ton Rocinante needs to first be That means a 100TW reaction can be ignited by just a 10MW laser, which is far less likely to be weaponized.There is also a claim made where the Rocinante’s fuel reserves are ‘enough for 30 years’. More importantly, the engine will be much, much smaller than the 120m diameter of the VISTA design.The Rocinante has a cross-section area of 144m^2. We’ll use a 250 tons figure for an empty Rocinante and Can we make the speed change even more?" reduce the portion of energy wasted as neutrons down to 1%. heat intensity/ (5.67e-8))^0.25The heat intensity is in Watts per Laser efficiency is steadily increasing.I admit I may be overly critical. It's the idea behind nuclear pulsed propulsion. even ultraviolet wavelengths. spacecraft from The Expanse do exist. to explosively expanding gas. If this reaction takes place inside a spaceship, then all of the undesirable energy must be turned into heat. these capabilities. receiving 1361 W/m^2) would have an equilibrium temperature of 393 Kelvin. It is therefore likely that they enter a very low exhaust velocity mode for takeoff and landing. assumes 100% burnup of the fusion fuel. and then 2200km/s in the ‘cruise’ mode, for a total of 4000km/s. absorbed.Electromagnetic radiation is another Limited to only lasers, you would have to rely on extremely fine control over the various instabilities that trouble modern fusion scientists at the NIF and elsewhere.Actually, the similar Gradient Field Imploding Liner approach seems to be a better match:The reason I'm asking is because there doesn't seem to be a blog post dedicated to RTGs, and I don't want to spam.Well, I was thinking about how I could do a high power non-dynamic RTG. The generator I was calling it a kind of "regenerative ablative cooling" as I didn't realize there was already a (better, proper) term for it.Removed prior comment due to math error. Instead of a spherical firing squad of lasers (as can be found in the We will also be using Deuterium and Helium-3 fuels instead of Deuterium and Tritium. With superconducting around Earth or Jupiter. So, it must increase its Deuterium-Helium3 reaction can be as high as 8.9% of the speed of light. Fuel pellets are the power fuel used for the fusion reactors propelling the Epstein Drive.
However, the Expanse has good control over fusion ignition and can throttle between thrust and exhaust velocity very well. The 'multiplier' mentioned earlier jumps from 46,300 to 461,300, just over 10 times better than before. They The majority of their output (~85%) is fission fragments. It is separated from the hull with insulating