HOME | DD
Jepray — LDS slow ship Colony class
Published: 2012-12-24 01:39:27 +0000 UTC; Views: 1927; Favourites: 15; Downloads: 41
Redirect to original
Description
A slow ship or Generation ship type colony ship with 2 huge spin hab units it is a floating city in space where generations grow up and grow old as the ship travels the gulf between systems before FTL travel is discovered... the trip could take hundreds of years to complete in these pre-FTL ships... Self sustaining Life support and food sources in the ship to ensure that they will make it to the target planet alive and healthy...Related content
Comments: 22
Ha ha, nice colony ship!! 
One thing I was surprised to learn about STL interstellar travel is the large amount of energy required to attain high sub-light velocities. Let's say a slowboat weighed 107kg (the mass of the Sark-1 solar sail interstellar ark design) and travelled at 10,000 km/s (almost 590 times the speed of Voyager 1, fast enough to reach Alpha C in about 130yrs.). The starship's kinetic energy would be 5x1020 joules, equal to the total world annual energy consumption in 2010. KE=1/2(107kg.)(1x107m/s)2=5x1020J
This is the minimum amount of energy required to accelerate this ship to that velocity. A rocket engine would take far more, because much energy would go into accelerating the exhaust stream, and even assuming a magic space drive that converted stored energy directly into kinetic energy, there would still be inefficiencies. Leading experts say that obtaining the energy for a starship may be the primary challenge, even once we have the technology to build one. However, we already generate huge amounts of energy through fossil fuels- mere chemical energy!!- just imagine how much more energy a spacefaring society that possesses widespread space solar power and fusion reactors will have access too. Still, even a colony ship requires great amounts of energy, and to go faster- so we could get data return from a mission in the lifetime of those who sent it, for instance- will take much more since KE goes up to the square of the speed, and mass increases at relativistic speeds. Even with small payloads, energy is the limiting factor of STL space flight.
Also, remember the 1st. rule of space combat. A pebble weighing one gram (1x10-3) will hit our slowboat with KE=.5(1x10-3)(1x107m/s), which equals 5x1010joules, which is supposedly equal to the yield of a Massive Ordnance Air Bomb (MOAB), the second most powerful non-nuclear weapon ever designed. And it is only one pebble. Our starship will need a thick shield to dissipate the smaller impacts from dust grains, and maybe lasers could be used to disintegrate potentially deadly impacts with interstellar "mines" like a stray pebble.
👍: 0 ⏩: 1
shielding for the ship is an issue for speeds available in space... also the fact that you can only go as fast as your engine output allows, need to enter somewhere close to light speed requires an engine that can put out energy at or near lightspeed values... also currently the fastest engine we have that actually works is an Ion engine, that is currently heading outbound from out system, but it has almost no thrust.. so its gonna take awhile for that little probe to hit anything near its possible top speed...
👍: 0 ⏩: 1
Man, real late reply, but I was just wandering through again, ha ha. 
With rockets, yes, the mass ratio issues imply that you need an exhaust velocity somewhere close to your desired final velocity (some significant fraction of light-speed, for interstellar travel). This is because the ultimate speed of a rocket depends on the fraction of its mass that is propellent, and at what speed the exhaust is ejected... and even with the best rockets, all the interesting missions require your ship to be stuffed to the gills with fuel. The energies and temperature created by such atomic-powered "super rockets" are extreme, too. Imagine riding a rocket with a mass of 100,000 tons which weighs 10,000,000 tons when loaded with hydrogen fuel, propelled by four engines in each of which the energy equivalent of 97 Hiroshima bombs is released each and every second- for an acceleration period of ten years. XD It may be powerful but it sure isn't elegant.
However, there is a way to achieve cosmic velocities without carrying any fuel or propellent along- the solar sail. A vast, lightweight reflective sail can be driven along by sunlight, since photons have momentum and push on the sail when they bounce off of it- so just build a suitably gigantic sail, rigid space-proof rigging, and attach it to your space boat to literally sail amongst the planets. Space sailing has actually been demonstrated in interplanetary space by the IKAROS mission, and NASA put a small sail in orbit recently, the Nanosail D. The limitation is that as you get farther away from the sun, the intensity of sunlight drops off according to the inverse-square (twice the distance, four times less intensity) and the acceleration of your sail drops accordingly. We can still use them for interstellar flight, by making a close approach to the sun, picking up as much speed as possible and flying outward, furling the sail once we are too far from the sun for it to be useful. The sail can be used for deceleration at the target star when we get there. The downside is that such craft would take a millennium to reach even the nearest star. Faster trips are possible if we build huge super-lasers to beam light to the sails, thus continuing to accelerate them far beyond the solar system.
👍: 0 ⏩: 1
there is another powersource, with a very High Impulse to it, but... its a nuke, stuck to the back of a starship... Set it off, against a very reinforced plate... and Boom! your zooming off! into space at a very high rate of speed... of course its a NUKE your setting off... soo there is that... The solar sail is a proven power source, but yeah, limited to in-system travel. That you need a sun for solar winds, so it would not work out in the deep black, between systems. Its gonna take time to make working space folding engines.. someone did the math for a Warp engine... so who knows... the distance between us and a nearest neighbor.. is vast, to a large degree... it will be interesting to see what they actually make to get across the gulf that is space...
👍: 0 ⏩: 1
Yeah, the nuclear pulse drive is the other main nearer-term propulsion system that could be used to send multigenerational space arks or "worldships" out to the stars. Nukes have much higher energy density than chemical fuels, but even more important, external nuclear pulse engines have no combustion chamber to be vaporized by the high temperatures, so the debris from the nuclear pulse is hurled off at very high speeds... making a far more efficient rocket than the feeble chemical engines and the temperature-limited NERVA nuclear rocket.
Dandridge Cole's related Helios nuclear pulse concept took this to a whole new level of insanity by proposing to detonate the nuclear energy capsules inside the spacecraft to heat water used for reaction mass, but seems to be less efficient than the baseline Orion craft for various reasons, despite being able to capture a larger fraction of the bomb's power. up-ship.com/blog/?p=5353 You gotta love the atmospheric nuclear pulse ramjet, though. XD
As for FTL engines... at this point, it seems likely that if we do launch a starship in the next few centuries, it most likely won't use space warps to instantly bounce around the cosmos. It has been both theoretically shown and empirically demonstrated that no object that has mass can be accelerated up to or beyond C, and physics-as-we-understand-it doesn't show us any dodges around this limit, and even suggests that FTL trips would lead to time travel and all its associated paradoxes like killing your grandaddy before he beget your mother, so you can't exist to kill him. XD This is sad for people like me who want to explore the galaxy. We are basically told that space warps are a matter for fantasy only, that while traveling at high relativistic speeds would allow us to travel extraordinary distances in our own lifetimes due to time dilation the energy and shielding problems are likely intractable for a long time to come, and that the voyage to even the nearest stars will most likely take several hundred years, traveling via multi-generational worldships. Maybe we could travel faster, round-trips might be feasible, but only with extraordinary efforts like huge arrays of lasers pushing a photon sail, and so on. But it is good to know of some possibilities for reaching the stars, even if they require extraordinary commitment and patience.
But, who knows? Many of us feel there should be a way to reach the distant stars other than the endless flight through deep space. We don't know everything about physics, there are still many unsolved mysteries, and perhaps new possibilities for space propulsion will be found with new physics... just as Maxwell's realization that light exerts pressure led to the idea of space sailing, and the discovery of radioactivity led to atomic power, and the discover of the laser led to whole new technologies. Perhaps there are loopholes to Einstein's theory of Relativity. It is very exciting that such ideas as wormholes and space warps can be explored today, even if they are only mathematical toy models with only a tenuous connection to physical possibility so far.
I suspect, however, that there are many possible ways to reach the stars- from huge world-ships containing an entire society traveling much slower than light, to micro-miniaturized payloads flung on masse into the void, to sails pushed by super-lasers and so on and all the other ways a species may try to extend their presence into the cosmos at STL speeds, and perhaps even super-luminal methods if nature ultimately allows for such things. We need to be prepared to explore all the possibilities.
👍: 0 ⏩: 1
We need to make an improbability drive fast then!
👍: 0 ⏩: 0
It would be a fairly serious clash of cultures, on one hand you have a ship built around the principle of a wing and a prayer, its people clinging to an ideal, only to have hopes dashed. The other is a planet already flagged and tagged. Will the ship folk turn out to be xenophobic, will the planets residents be selfish?
👍: 0 ⏩: 1
Yes, that is a story in itself!
👍: 0 ⏩: 1
thanks, no reason for it to be too fat and slow, the spin habs to give them gravity for the long durationand enough space in the center of those modules to hold supplies
👍: 0 ⏩: 1
Tell you the truth, this might actually be the first time I've seen a sleek colony ship.
👍: 0 ⏩: 1
So long as FTL travel isn't developed between their departure and arrival, and contact with hostile alien species made...
Rendering them little more than a target in a war they never really had anything to do with.
I wonder if anyone's written a story along those lines yet?
👍: 0 ⏩: 2
YEs, actually I have read storys along those lines, where the slow ships get to there target planet to find it already colonized by a new FTL ship... kinda a " Thanks for playing and Fuck you!" lol
👍: 0 ⏩: 1
*whistles innocently*
👍: 0 ⏩: 1
and I know ^ that guy wrote something along those lines too I think...
👍: 0 ⏩: 0