shynung

True. Maybe he plans to redirect some profits from Tesla to fund this project? Also, their timeline states that Red Dragon will be ready before this. Maybe they plan to use that as a learning tool, the way they used Grasshopper to learn how to land rocket stages?

And he funds it by... stealing underpants?

Yeah, that. I misunderstood the original response as 'doesn't make use of the stock toolbar'. I stuck with 1.1.3 for now, since my connection is a bit spotty due to weather (can't update quickly enough). Glad to see this sorted out. And yes, I do prefer the stock toolbar, not Blizzy's.

It doesn't, at least not in the functional sense. Blizzy's Toolbar just stood out among KSP's stock UI system, and I prefer to not have that. Plenty other mods integrate themselves using the stock toolbar just fine, Nertea's collection in particular. What makes the stock toolbar more problematic than Blizzy's, if I may ask?

Aw, shucks. Well, thanks for telling.

Is it possible to run this mod without using Blizzy's toolbar?

I think this is something we can engineer to a degree. Genetic engineering can create fast-growing crops and trees, geoengineering can make previously inhospitable areas inhabitable, and various technologies can improve our resource extraction capabilities. In short, we can intensify the processes the we require to get resources enough so that a smaller area can feed a bigger population than it was before. On the other hand, Mars doesn't have the resources we are used to collect from our surroundings. Contrary to popular belief, Mars has no arable land, nothing to plant crops on. There are no easily accessible water on the surface; one must look for water by drilling a well, which takes time and energy. And more importantly, it doesn't have a breathable atmosphere, nor does it have a planetary magnetic field to protect its inhabitants from space radiation. The atmosphere is also very thin, which means there are little protection from incoming projectiles; falling space rocks are a dime a dozen. Compared to Earth, Mars have little to no Carrying Capacity to speak of; we'd have to build infrastructure to expand it ourselves. And here's the kicker: anything we invent to give Mars some Carrying Capacity would be usable here. Using technology initially earmarked for colonizing Mars would make the hottest of deserts habitable. Efficient soil-less farming techniques would enable agriculture in even the harshest environments on Earth, opening more areas for settlement. Efficient water extraction, processing, and recycling technologies would help sustain cities that have limited water supplies, and so on. In short, whatever we do to make living on Mars possible, it would improve our own planet's Carrying Capacity further. And we don't have to haul our carcasses all the way to another planet to get these benefits. Now, if our goal of shipping people to Mars was to set up an outpost, say, for scientific research, then it starts to make sense. There are some knowledge that we can't acquire by any way other than spending some time living on Mars. This might be something like knowing environment characteristics, accurate data on resource location and richness, and some other things This knowledge may later help us colonize Mars, when we can't stretch Earth's Carrying Capacity any more. For this purpose, building a space-railroad to Mars is unnecessarily expensive if a simpler, cheaper vehicle can do the job. Only after significant surface presence is established can we justify spending more to develop additional infrastructure to act as space-railroads.

Then forgive me for being ignorant, for I am not a biologist. Do explain.

And why is that? Currently, Mars doesn't have any native inhabitants that wanted to go here, and no colony to speak of. Where is this load of passengers coming from? Colonists? Musk's concept of sending 100 people in each outbound trip would make only a small-ish town, even smaller if not all of them stays. And there's only one outbound trip every 2 years or so. How long until there's enough colonists so that there are enough people wanting cheaper Mars-bound tickets there, necessitating building the space-railroad infrastructure necessary to achieve that? That means I have no objections to the points I ignored, or I see no need to debate it further. There is nothing malicious in me attacking other points of your argument, it is simply how I discuss and analyze other people's ideas. Me or other people attacking auxiliary points mean there is something weak in them that we wish to probe further, in order to strengthen it or replace it with a stronger idea. Ah, the Lebensraum argument. Here's our situation. The living conditions in almost every landmass on Earth is much better than that of Mars (remember, Mars has no breathable atmosphere, or a planetary magnetic field). As you can see, our planet isn't currently overcrowded with humans yet, so there is no immediate need to ship people off-planet efficiently en masse. Your colonization architecture comprising of cyclers and dedicated cargo ships seemed to suggest that it is best used to ship people off-planet efficiently en masse. Why should we build upon your architecture?

That's because the railroad company knew ahead of time that there is actually something worth carrying elsewhere. Farms, mines, forests, oil wells, etc. Mars has none of that - hell, it doesn't even have breathable air! Think of it like this way: Mars is a far-away place that takes a considerable effort to reach physically, yet doesn't have anything we can't easily acquire here. Even if it is possible, why would anyone spent fortunes building a railroad there?

They don't. In its early history, US railroad companies focused on connecting industrial sources (mostly mines) to their respective processing plants, then later transporting people between large cities. When steam engines first arrived at the scene, they were small locomotives than can carry a limited amount of water and fuel. At predetermined locations (water/fuel stops), the trains would stop for a while, refilling their water and fuel supplies, and then continue on their journey. It is these refilling stops that later become railroad towns, whose residents thrive from the existence of the refilling stop itself, taking job opportunities offered by the railway company to run the refilling stop, as well as being a local transportation (hence, trading) hub. The railroad companies themselves have no interest in building a rail line to the middle of nowhere, with no resources nearby worthy picking up and transporting elsewhere, just to start a town there. It would generate no profit. Railroad towns grew because people see opportunities in servicing trains stopping in a refilling stop, enough so that some people willingly build houses nearby to keep themselves available to the next train using the stop. EDIT: @Northstar1989 You might want to start a new thread on your approach to Mars colonization. Your continued... support... to your ideal method of colonization is starting to derail this thread.

What you're proposing would be akin to building a railway network to a town that doesn't even exist yet in order to settle people there. Musk's plan would be similar to sending settler wagons to the same location to do the same job. Now, if Mars have enough people there to be considered something more than a scientific outpost (like what we have in the south pole), then building an interplanetary logistical 'railroad' of cyclers, shuttles, stations, and landers, where the needs for efficiency outweighs flexibility starts to sound like a good idea. Until that point, I think we should send the space equivalent of settler wagons that are more flexible in order to be prepared for anything the Kraken throws at us.

Properly engineered, what's the chance of a joint or valve failing before the turbopump? I'd bet that they'll last longer than the engines unless underengineered to a significant degree. That decreases redundancy and reliability; if a big pipe supplying several engines leaked or failed, that would affect all the engines feeding off that pipe. Providing each engine with its own fuel delivery system would ensure isolating a problematic pipe's effects to the engine it supplies. Yes, it's heavy. But for a pioneer lander needing ultra-reliable hardware, I think we can spare some more mass on redundancy. Looks reasonable to me. The reason SX used many engines in one stage is to reap the benefits of mass production, so that the cost of each individual engine is manageable. I believe replacing a few engines after each flight would trouble the flight plan rather lightly, unless ITS wasn't planned to have its engines individually replaced; if so, why bother with reusability if the rocket stage is junked every time one engine out of 42 quits?

I like to think that SX engineers have higher standards than their Soviet equivalents. They did 9 engines on one stage successfully. Then again, 42 is a lot, so we'll see. BTW, N1 was plagued by a lot of problems unrelated to its engine cluster design. I read somewhere in Wikipedia that the 3rd launch failed because a stray bolt got into the turbopump.

@Northstar1989 Your mission architecture involving dedicated landers, cycler habs, and cargo-crew separation is more appropriate when there are permanent settlements on Mars that require a continuous logistics train. Right now, Musk's colonists is going there as pioneers, which means there are no infrastructure waiting there to support them. That's why Musk aims for a simple, reliable vehicle to get them there; it's more akin to settler wagons, as when one fails, sending another one is as easy as building/preparing a duplicate vehicle and finding another group of colonists. Don't get me wrong, losing a whole ship of Mars colonists would still be a disaster. But it's easier to plan another mission when there's only one vehicle type to be concerned with, rather than an entire cycler-lander-cargoship fleet to deal with. The idea is that the engines+pumps (in a rocket engine, the combustion chamber, nozzle, and turbopump are designed as a single unit) are identical, so the vehicle can reap the benefits of mass production. Plus, having many engines add redundancy, so the vehicle can withstand multiple engine loss events. Pipelines are just a bunch of pipes; the biggest expense on them would be planning the pipe routing, and that'll be done only once or twice.

Pretty sure. It's being jointly developed by MSNW and The University of Washington, and backed by NASA through the Innovative Advanced Concepts program. They're aiming for a full scale ground test by 2020, and orbital demonstration by mid-20's. MSNW doesn't exactly have their own space program, though, so it's up to NASA or some other organization to actually use the fusion motor for their spacecraft.

I sure hope MSNW finishes that fusion rocket they're working on sooner than later.

Why is methane a gas, but methanol a liquid at room temperature? What's in the OOH branch that makes methanol a liquid at room temperature, where methane isn't?

I really wish we can buy the KSP franchise and hire someone passionate to keep it running. Someone like Star Citizen's Chris Roberts.

IIRC, gravitational waves don't carry momentum. So even if we can make artificial gravitational waves, we can't use it for thrust. The only possible way to add momentum without propellant in vacuum is a photon drive. It's pretty power hungry, at 300 MW / N of thrust, so TWR will not be great.

@Veeltch A Titan II ICBM burns Aerozine 50 and NTO, which reacts into NO/NO2 (can be either), H2O, and CO/CO2. Majority of the exhaust are NOx and H2O, which are nearly invisible, as shown in this photo of Gemini 11 launch. Note: The smoke from below isn't a part of the exhaust plume, it's water sprayed onto the pad to reduce noise.

@Bill Phil @RocketSquid It's mostly a matter of the exhaust gases' molecular mass. A hydrogen-propellant solid-core NTR has a higher specific impulse than a pure chemical hydrolox motor despite lower chamber temperatures (about 2000 K, as opposed to the latter's 4500 K), primarily because it spews hydrogen gas (about 2 amu) whereas the hydrolox motor spews out steam (H2O, about 18 amu). Generally, for the same chamber temperature and pressure, lighter molecules move faster, which effectively increases specific impulse. This is also why hydrolox motors running rich sometimes have a higher specific impulse than stoichiometric-running motors, despite lower chamber temperature/less energetic combustion, which is because the average molecular mass of the exhaust is lower due to unburned H2 in the exhaust. On another note, this explains why kerolox rockets have enormous fiery plumes compared to hydrolox ones. I'm willing to bet that the fuel/oxidizer ratio is optimized to burn the kerosene to CO as opposed to CO2, in an attempt to improve specific impulse. The large plume often seen trailing kerolox rockets are therefore, I suspect, the CO in the rocket exhaust reacting with atmospheric oxygen. This fiery plume is not seen in kerolox motors burning higher up, such as F9's second stage, because there aren't any oxygen for the CO to burn with.

Shock absorbers are needed when using a rocket motor that thrusts in pulses rather than continuously, like the Orion NPP. This is because neck-breaking jerks are generally unpleasant to the crew, and often wreaks havoc on the machinery; the shock absorbers are meant to ameliorate them into slightly gentler nudges.

@ChainiaC Yeah, I don't think we'll get spaceborne nuclear reactors for a while. Not unless we start going interplanetary at an industrial scale.

I thought the NERVA designs were rated for 4-5 hours of core life at maximum output? Surely a Terra-Mars burn wouldn't last even an hour?