GreeningGalaxy

I love the idea of vacuum balloons, but I don't think they're really something we'll see in our lifetime. I remember reading some excerpt from a contemporary sci-fi story featured in Popular Science that had vacuum airships, with the envelope contained by some sort of handwavium super-strong force field (premise was that we ran out of helium), but that's obviously quite a ways off. Meanwhile, you can probably get very close to that level of buoyancy by combining hot-air balloons with light-gas ones - a hot-helium balloon, or if you feel like living on the edge and doing the most dangerous things you can possibly think of, a hot-hydrogen one. It's a bit of an engineering challenge to figure out how to heat the gas through a sealed envelope without setting something on fire, but substantially less of an issue than making a lightweight vacuum chamber that size.

Twitter follower of Bird Rights Activist.

That's certainly a possible and effective propulsion system, but not nearly strong enough for interstellar travel, since you lose a lot of energy in the conversion to heat, and most of it shows up as thrust instead of Isp. Fusion thermal rockets could easily have the thrust to launch massive payloads off the surface of Earth, but they'd only have an Isp of a few thousand seconds - plenty for mucking about in the solar system to your heart's content, but not even close to what you'd need for an interstellar spacecraft. Ambulatory Cortex's suggestion for a dusty-plasma fission fragment rocket is good (although I may note that it doesn't have "15 million (seconds) Isp," that's actually 15 million m/s exhaust velocity, which equates to an Isp of about 1.5 million seconds), as would be an intertial confinement fusion system (in which lasers are used to zap the deuterium/tritium fuel and make it fuse). Both systems have very high Isps and low thrusts, which is what you'd need for an interstellar trip. Communication delays are indeed going to be long, but I see no reason to believe messages will necessarily have to be short or basic. With such long timeframes involved, there's no need for a particularly high rate of information transmission (you can spend a few hours transmitting a few gigabytes and it's no harm to anyone, meaning that Earth gets lots of time to make out the dim pulses from all those light years away), so you could reasonably imagine that the crew members could all record their own little video files to send back home, if so they chose, which would then be sent along with the daily "mail" transmission from the laser array along with telemetry and such. Of course, I'm no psychologist, but I might also point out that the best crew for a generation ship would be people who don't have any loved ones or particular investments to leave behind on Earth - it's not like they're coming back. The capacity for sending mail back home could certainly be there, but if your crew is always using it to contact people they miss, that could be a sign of a serious morale issue.

2/10? I think I've seen you before.

8/10 noice

Your Magikarp spontaneously appears into reality, then disintegrates due to sigma/delta decay. Our universe's vacuum energy state cannot support it. I wish I knew the exact syntax, function, and background for every Bash/Linux command ever.

Quote: ok Other 'quote': what Link: aight Total: 7/10

As the portal closes, I perform a local 4D polar inversion on it, causing them to expand to a radius of nearly a kilometer. The entire hill is sucked through into the vacuum, and the portal collapses behind it. You jump clear and grab onto the edge of the portal at the last second, but now only have a flat area of dirt to your name. My hi- wait, is that grass turning into goo in the vacuum? And ugh, look at that earthworm.. oh god, is that a gopher hole? What have I done? Someone else can have this hill. I need to go take a shower.

It has a special knife that can slice through spacetime and open gateways to parallel universes! WARNING: Using this function may create specters. We are not responsible for any souls consumed as a result of your use of this feature. Universe-slicing is banned in some states; check with your local authorities before using. Warranty void if used to access Hell, the Shadow Realm, Elysium, fractal dimensions, or universes containing Luminiferous Aether.

I draw a malformed apportation circle around your flag and activate it. WHUMP! Your flag is now everywhere, in very tiny little bits. My hill + live death circle.

I made a multi-stage rocket to launch a mid-sized KSPI ship into orbit, which, well... ...Turned out to be an SSTO. This overbuilding thing is becoming enough of a problem that I've considered switching to RSS.

I usually pop open the terminal, start irssi, and go on #KSPOfficial to brag about what I'm going to do next.

Yep! I recommend the Distant Object Enhancement mod, too - it makes all the other planets show up as bright dots in the sky, as well as other vessels that are close enough to be seen. It really adds to the experience.

Having a pre-landed return vehicle on the surface before you descend makes all kinds of logistic sense - once the lander descends intact, it's there, and it then doesn't matter how well you land the descent vehicle as long as you don't kill yourself in the process. With single-lander missions, you have to be careful not to damage the engine on landing or you might never be able to go home, but with separate vehicles, you'll know before you even launch the humans whether or not the uncrewed ascent vehicle landed safely. If it made it, you're good to go; if it didn't, nobody was relying on it to get home because they haven't even left Earth yet. That also opens up some nice ISRU possibilities - the lander could make methane/LOX fuel from stored hydrogen (or found water ice) and CO2 from Mars's atmosphere while it waits, for instance. As for parachuting to the ground, it's technically possible (albeit very kerbal), but for reasons of safety and also being able to carry a lot of scientific equipment down too, it's probably better to land a full habitat with just enough fuel for touchdown. Such a thing wouldn't weigh very much, and you could use it as a base of operations prior to leaving on the ascent vehicle. Interesting idea, but I think the MOOSE system and its kin are not really the kind of thing you want to be using regularly.

Robert Zubrin's Mars Direct plan involves aerobraking over Mars in multiple passes, using a deployable skirt type of thing on the bottom of the capsule to increase drag. It's not a replacement for rockets, especially not for landing, but it does save a lot of delta-V. Mars's atmosphere is thin, but not so thin as to be useless for aerobraking. If you think about it, most of the rovers sent to Mars have used parachutes during some part of their descent, which slowed them down a lot - if you brought your orbital periapsis within a kilometer or so of the surface, it's hard to imagine that you'd stay in orbit, so aerocapture over Mars is probably possible too, if at a considerably lower altitude than Earth.

Picking apart your design a little bit: dual centrifuge rings that counterbalance each other, looks like like 2001 space odessy station, but they spin in opposite directions. --Looks like this has been addressed by others. counter-rotating rings would work okay for a ship that has to maneuver a lot, assuming you had some way of making rotor bearings that never wear out, but for a generation star-hopper, I wouldn't think you'd need that. The main benefits of that setup would be no gyroscopic forces (the rotating rings cancel each other out) and having a zero-G segment at the center, so if you don't actually need any of that, I wouldn't recommend bothering. Long central spine, engines at the front pulling rest of ship --I really would not do that. For a ship designed to go between stars, you're going to need a LOT of engine power / exhaust velocity (like fusion, as you suggested). That's going to produce some very intense neutron radiation, which you're going to want nowhere near your habitat. engines angled several degrees outward to keep exhaust from frying the rest of the ship. --Yeah, even this probably wouldn't be enough. The radiation from the exhaust won't be directed in a pencil-thin, coherent beam, it's going to be shooting off all over the place. See Project Rho's items on shadow shields; that's probably more what you'd need. Some sort of 0g observatory near the back? (possibly 0g recreation somewhere as well?) --My fun-loving side says "do it do it do it!" It might be slightly sub-practical (I guess ideally you'd have the crew confined to the rings and save the inner column for all things starship-related), but Kim Stanley Robinson's Red Mars features just such a thing (with the whole ship spinning) so I say go for it. It'll make your readers wish they were there. pressurized tunnel in the truss, allowing access to much of the ship. --I suppose this ship will need to be rather big, much bigger than you'd really be able to expect for something totally EVA-accessible. The central column will probably be packed with machinery, but I don't suppose putting a small maintenance tunnel system inside is a bad idea. Making it pressurized might be very challenging if you want it to be able to access everything important, but then you'd have to crawl through a tunnel full of sharp-edged, catch-point-ridden machinery in a spacesuit. Kevlar compression-style space suits, maybe? Whatever you do, don't make the tunnels that go close to the reactor/drive commonly used. If you do choose to include them, remember that anyone you send down there is probably not ever coming back up. Could some of engine waste heat be used as life support heat? (as design or in survival?) --Sure, that would probably be pretty trivial. Assuming the heat travels from the cold side of the generator to the radiators in a fluid of some sort, just have a few of those pipes go to the HVAC system and back on their way to the radiators. That'd be as efficient as anything in terms of heating systems. relatively simple propulsion, not antimatter, fusion maybe? --It'll be a while before fusion becomes "simple" in any sense, but it still looks rather attainable in the long term even so. You probably won't get the delta-V you need from just an inertial fusion drive with onboard fuel/propellant, though - maybe something like a Bussard ramjet? Those are tricky, because you have to do proton-proton fusion (which is hard), and also because it's very hard to go faster than your exhaust velocity, since the drag from all that hydrogen you're collecting slows you down. Still, for a generation ship, 12% of light speed isn't terrible, and collecting your propellant from the interstellar medium means you won't have to worry about gigantic propellant tanks. There are lots of different possibilities for very strong deep-space propulsion systems. I recommend poking around near the bottom of the drive table on Project Rho - there's some very cool stuff to be found there. You could also do what lots of sci-fi authors do, and just say that the ship is powered by a "stardrive" being some kind of extremely powerful rocket driven by unspecified processes. Personally, I love to go into the technical details about stuff in my writing, but glossing over is often recommended for this kind of thing, because it gives you more wiggle room and doesn't get you caught between the rock of your plot and the hard place of scientific realism. Closed cycle life support, algae farms, yeast, made into palatable dishes? --According to my mother (a biology professor), this could actually be substantially harder to do than a sufficiently powerful propulsion system. Sure, it can be done, it's just that there are a lot of variables to account for, and a lot of really tiny things that need to be kept alive. It's possible to do this, but you'll need to make sure that your crew is very careful not to destabilize anything, and that you have lots of buffering options to keep stuff stable as inevitable changes in environmental conditions occur. This isn't as simple as just having enough plants to make oxygen for your crew, you also have to take into account all the microbes that plants, humans, and whatever other critters your bring along are going to depend on. The biosphere on Earth is very interdependent and adapted for exactly the conditions on Earth, so getting it to thrive in a spaceship is going to be a very big obstacle. Make sure you have lots of room for storing oxygen, CO2, and trace nutrients, some chemical reactor systems to stand in for various biological processes in case of emergency (ie a CO2-to-oxygen recycler if all your plants die), and lots of space to store emergency food. You'll also probably want some frozen microbe cultures too, in case someone has a gut flora problem or one of your artificial biomes loses its microbe population. Communication system with earth? (not superluminal!!!) --This is relatively easy - just stick a great big laser on your ship, on a turret that can track Earth as your ship spins. You can decide what wavelength you want; I hear that microwave lasers are relatively easy to make powerful (and go through gases with minimal loss), but you can also try to go for visible light or even shorter to maximize your range. Wikipedia has an okay article on this. Mostly, your most essential thing will be transmitting your signals as a thin, directed beam instead of omnidirectionally. What exactly this is depends on how far you're going - if you're headed to Alpha Centauri, you might just need a large radio dish, but if you're headed halfway across the galaxy, you'll need a laser that can still be seen through all the interstellar gas in the way, which will need to be very powerful indeed. repairs and maintenance done by remote control repair bots. (not fully autonomous) --Sounds good. For a generation ship, self-repairing systems are kind of a must. The need for human input does seem rather inevitable, but for the most part, a society advanced enough to build a Bussard ramjet and maintain a stable ecosystem inside a spacecraft shouldn't have much trouble making a near-totally-autonomous repair system. cargo for setting up colony on extrasolar planet --Sure, just disassemble the habitable modules of your ship and fly them down one by one. If you pick a planet that already has life, good luck - even putting aside the possibility that someone sentient lives there, the interaction between Terrestrial life and alien life is going to be very unpredictable and probably dangerous (don't go around eating whatever you see, and be mindful that breathing near something is probably a good way to kill it, or you - the the microbes in your body might be extremely infectious to local species, and vice versa). Maybe you could go for something where the planet's temperature is perfect and it has liquid water, but its atmosphere isn't breathable and it has no life? Then a human could walk around with just a breathing mask. Of course, you'd probably start terraforming the place right away whether you wanted to or not, because you'd track microbes all over the place and leave behind tasty chemicals, and eventually you'd introduce something that likes the local environment, and, bam, proto-biosphere. If you want to be really clever and wildly speculative about colonizing a planet containing life, you might do some large-scale preparation in advance: send a sterilized uncrewed probe to the surface, take samples of the local flora and fauna, and then either grow yourself some humans that can exist in that environment, or else find a way to convert a living human to be compatible. You'll then need to grow enough specimens of local wildlife to use in your shipboard biosphere, and then maintaining that gets a hundred times harder than it would be if you used Earth life. All of this has some pretty serious ethical and logistical ramifications, obviously, but could easily make for a very interesting story. Just watch your step. way to angle floors slightly due to offset gravity during thrusting??? (would that be necessary?)(i do want rings, more space for population that way) --You could have variable-angle floors (probably by having the rings made of a number of cylindrical modules, and then just rotating those). Easier than that, though, would be to design the ship for an always-running propulsion system. You'd get where you're going a lot faster if you have some kind of torch drive that burns constantly throughout the trip - accelerate constantly up to the halfway point, then flip over and decelerate the rest of the way, which will bring you to a stop at the destination. This has another added bonus: if you were to fire the engine hard enough to accelerate at a constant 1 gravity throughout the trip, you could do away with spinning entirely, and have the gravity come from the drive alone. A Bussard ramjet could probably attain this kind of power, but in all honesty you're probably better off with an unspecified handwavium stardrive (or antimatter, but you said you didn't want that) if you go for this. Regardless, You'll probably want to plan for having the engine on more often than not, because doing a short burn at the beginning of your trip and then trying to coast the rest of the way will probably not get you there in a short enough time to be meaningful (try millions of years). If you really want your ship to hold up to lots of varied thrust, variable-angle modules would work well enough, but like the counter-rotating rings idea, it just doesn't really seem necessary for the kinds of things your ship will be doing. This sounds like a cool story! I hope you at least let us all read it when you're done.

I remember reading in some book (unrelated to crop circles for the most part, it was about weather and stuff) that showed a picture of grass that had supposedly been flattened in a circular pattern by the brief touchdown of a small tornado. I don't remember what the book was or whether or not it was remotely legit, but that's another non-conspiratorial idea about how some circles may form. I guess.

Compared to liquid rockets, SRBs are very simple - in a liquid engine, you need to have all kinds of plumbing - pumps, pipes, a heavy nozzle and reaction chamber, and all that stuff. Worth taking with you to orbit and beyond, but if you're just going to use it up to a few kilometers and then drop it in the ocean, what's the point? Solid boosters are just cans full of boom, so they're far easier to produce, and they don't have nearly as many delicate components to get broken when the splash down, so refurbishing and reloading them is a possibility. As things like SpaceX's latest endeavours (namely landing the liquid-fueled ascent stage intact after launch) become standard, I expect SRBs will see less use in the common space industry, but in the meantime, they offer an attractive means of cutting down that all-important cost per kilogram. Meanwhile, what about composite engines? They have the advantages of being both throttleable and safable, and I think they're only a little more complex than a typical SRB (although I might be wrong about that), so while you'd still have to have to store a liquid in a tank and figure out how to pump it around (which isn't hard, but is harder than stuffing a bunch of solid stuff in a tube and lighting it), you also wouldn't have the heavy and expensive nozzles of the same variety you see on liquid rockets. Of course, it might be a little longer before composite engines see common use after the Virgin Galactic accident, but it seems like that could be another way to go.

Let's pretend GeneCash is not a troll (which is not an assumption I make, but whatever, I guess there's no point in begrudging anyone their sources of stupid/twisted entertainment. To feel better about myself for not being able to tell, I'll respond under the pretense that I'm preempting anyone who might think to agree with him). First off, it's true that we're not 'killing the planet' with greenhouse emissions. The planet itself will endure no matter what we do to it, as will life. Killing ourselves (ourselves being the human species) is slightly more likely, but still quite a while away. The main problem will just be inconveniencing ourselves. The human race will still survive if Belgium, Florida, and pretty much every coastline city on the planet ends up underwater, but that's the sort of think we don't really want to happen, and which will most definitely happen if we burn every fossil fuel we can find in Earth's crust(1). If we do that, we might also end up having to live underground as the surface becomes too hot for a person to adequately reject excess body heat, which would mean that the majority of the human population would probably die (but, fortunately, not all of it!), and we would, of course, see a mass extinction of a magnitude never before seen on Earth (but, again, it's extremely unlikely that everything would die, just most of it. Anyway, the greenhouse effect is extremely well-documented and has been clearly shown to be increasing(2)(3), so at this point it's less that it's hard to link greenhouse emissions to climate change, and more that it's very, very hard to imagine releasing this much carbon dioxide into the atmosphere and not seeing a substantial change in global climate. There's just so much evidence for climate change as a direct result of C02 emissions being a growing problem, and effectively no credible or verifiable evidence against it. We can keep trying to make pointless and far-fetched excuses about why it's "just natural," or caused by the gradual brightening of the sun over time, or the heat released just by "doing things" in accordance with thermodynamics (that's a new one for me, I admit), or we can listen when the evidence is presented, address it, and work to see if we can avoid making life very hard for ourselves later on. That would presumably require that a majority of people make a few of their decisions based on other things besides personal greed, which I'm honestly not very optimistic about, but my own opinion doesn't matter - these are just some facts.

As fossil fuels start to run out and we start to launch stuff to space more and more often, I'd think setting up some kind of large-scale water electrolysis system to fuel hydrolox rockets would be the best solution - then rockets would just end up part of the water cycle, and we wouldn't have to keep doing expensive drilling operations to get ahold of the propellant. In the meantime, since rockets are such an incredibly negligible consumer of petroleum and producer of emissions, there's absolutely no reason to ban kerolox rockets - that would just make getting stuff to space even harder, and it's already pretty stupidly hard, what with our society and economy structured the way they are (and also because it takes 10 km/s delta-V just to reach orbit). The less we hobble the space industry, the better. Despite what you might hear from the far right, basically nothing done by anyone in space (barring accidents and military stuff) will have any non-negligible negative effect on Earth or its permanent population.

This is pretty much the basis for my designs, but I still find myself adding small stylistic elements to my larger designs, like strut-caging undersized inline parts or doing everything in six-way symmetry. Or adding antimatter ejection systems to everything I build with antimatter, which is honestly all but useless. But yes, I have noticed that my sense of aesthetics is directly and majorly swayed by my sense of practicality (or rather, how well the ship ends up performing in-game, which I guess has no real bearing on practicality in real life, does it?)

At least for my bigger transit vehicles, mainly those I make with KSPI, I have a pretty solid set of rules for how stuff goes together that I stick to. I do pretty much everything in the cylinder-with-radials style, and rarely use side-mounted cylindrical things (like engine pods) unless I'm building something smaller. I'm rather fond of six-way symmetry with basically everything, and tweakscale is my best friend. I labeled some of the key design features frequently seen in my largest ships, in this case my latest Thalassa 3A torchship:

I installed Krag's Planet Factory pack. It's wonderful, but I had to ditch B9 to make room in my RAM for it, and it still occasionally totally freezes up my computer, but it's certainly well worth it. Today, I went to Thud. If you haven't seen Scott Manley's video about the Sentar expansion (or heard about it from somewhere else), Thud is essentially Hell Tylo. It also lacks an atmosphere, but instead of having slightly less gravity than Kerbin, Thud has 3.14 times Kerbin's gravity! I decided that, since I've been building such ridiculous ships with antimatter propulsion lately, that Thud posed enough of a challenge to be a good destination. I was not disappointed. At first, I was planning on doing this mission like most of my others: a large transit vehicle, a lander docked nose-to-nose with it, and the whole business flying out to the destination before undocking and the lander descending. I launched the GGSS Rising Spring, one of my Thalassa-class torchships. It's a true monster of a vessel with over 250 km/s of unloaded delta-V thanks to its plasma-core antimatter drive. Then I launched my lander, the infamous and loathsome GGLS Mjolnir, Descender of the End Times, the Lander To End All Landers. It made it up without a launch vehicle. The torchship could technically have done that too, but I was bored and felt like making a big rocket for it. The lander was flown by intrepid pilot and physicist Chaduki Kerman, who is my first female kerbalnaut since installing Texture Replacer, and co-pilot Herberry Kerman, a plucky planetary scientist rather new to the space program. The Mjolnir lander uses the same propulsion system as the Rising Spring, but carries much less fuel and payload. While the torchship has 250 km/s of delta-V and accelerates at just under 1.5 Gs, the lander has under 100 km/s and accelerates at nearly 5 Gs. Unfortunately, trouble happened: I'd forgotten to put forward-backward translational RCS on both ships! I tried my best to dock them with help from MechJeb, but eventually MJ gave up and started pointing the ships at random angles whenever I brought them near each other. Eventually I disabled MJ completely and tried manual docking, but before I finished, it occurred to me that the lander probably could just make it to Sentar on its own without any transit vehicle to dock to. Plasma-core antimatter propulsion is... maybe a little overpowered. the antimatter usage does check out mathematically, at least. With that, I started burning for Sentar with the help of MJ's transfer computer. The Rising Spring decided to follow, just for the science. If the Mjolnir struck the surface in a multi-megaton antimatter fireball, someone had to be there to figure out why, right? It lit its torch and tossed itself out onto a slightly faster transfer trajectory than the Mjolnir, allowing it to arrive at Sentar about 170 days ahead of the lander and give itself time to get into position. A little over two and a half years later, the Mjolnir arrived in orbit around Thud, joining the already-present Rising Spring. Wasting no time, Chaduki fired off a few short, intense burns to line up the lander's trajectory with a nice flat crater bottom on Thud's surface, and the ship started falling towards the massive moon. It soon became clear just how incredibly strong Thud's gravity really was. The lander did most of its descent at nearly a kilometer per second, almost two at one point. Fortunately, the engine was still stronger, and Chaduki managed to kill the horizontal velocity and get into a nice vertical descent over the crater bottom. Landing! Chaduki was the first out of the ship as it touched down, and struggled her way down the ladder in the three-G gravity. The Rising Spring captured the historic planting of the flag on telescope video, and a great cheer went up Kerbin-wide as the transmission was received back in the inner solar system. As soon as Chaduki declared the surface safe, Herberry hurried out to join her. He had a little trouble with the ladder (protip: DO NOT climb down ladders headfirst in 3 gravities!), but made it out alive, and enjoyed amazing views of the Sentar system and the rest of the solar system from Thud's slowly-revolving surface. And with that, the sun set on Thud, and Chaduki and Herberry became cultural icons of persistence and accomplishment across the whole solar system. Now they have a three-year trip home ahead of them, but they can at least make it in triumph and, more importantly, alive.

I've got this working for the most part in my game (.25) but mine also doesn't seem to want to do the right atmosphere/ocean colors and things. Anyone who has that .cfg Immashift mentioned, it would be super great if you could post it!

I had a Lemeny Kerman running around for a while. He was a sour character, and clearly guilty of embezzlement. On a frivolous and fruitless mission to construct an orbital linear accelerator station with antigravity repulsors, I encountered the frightfully relevant Mungun Kerman; he's currently aboard one of my larger transit vehicles bound for Jool. He'll set foot on the Mun before he retires, though, I promise.