Rune

It was kind of inevitable this would happen. A shame I don't get to enjoy 0.20 just yet.

Whatever you might have heard, the Universe is very finite and likewise contains a limited amount of material. And that matter is irrevocably evolving into a lower energy state with more chaos in its distribution. In the end, all that there will be left will be a tenuous mist of mildly warm, nonreactive fusion products and the last dwarf stars. And then the last white dwarf will cool down. Rune. Entropy rules.

And that is a reasonable reply that further clarifies the point. Well written, sir. But conceding the facts that are undisputable (i.e: the shuttle can do things no other vehicle that has flown can), I will still maintain that those capabilities come at great expense and are either of little use or capable of being done another way (so it's not worth it). After all, for what a shuttle launch really cost (500-1,500 million depending on who you ask and how you measure), you can do a lot of stuff. As to the specific Soyuz numbers... well, there's this problem with Soyuz, which one you pick? Are we counting the differences in launchers, model, etc? And Progress? What about the satellite launches by the same family of boosters, do those count as Soyuz payloads? What I think should be obvious is that the russians have never sold a seat to NASA cheaper than it costs them, and that the soyuz family has been refined to become the safest, best understood human rated vehicle in history. But in the end specific comparisons are not only difficult, but probably inconclusive and unproductive, because you are bound to pick a biased yardstick. But yeah, to sort of sum it up, I think there is a better way to anything the Shuttle did, or could in theory do. Capsules for passengers (because even old Soyuz can beat the shuttle at that, and I also believe you can do much better than that), tugs for cargo. Specialized tugs for orbital repair and resupply without getting humans in danger and increasing cost. Even, thinking on the future for when you have the basic stuff covered economically, it might be nice to have reusable upper stages to move the other stuff around, standardized station modules to establish systems of depots. Habs to endure the travel between them, and the landers and surface systems when we eventually get somewhere. A complete toolbox, in other words, instead of a swiss army knife. It would undoubtedly end up being cheaper for the results whatever you are after, IMO, and every piece is useful on its own. Not to mention each can be developed without "taking a decade out" on manned spaceflight, or without having your whole budget for manned spaceflight revolving around a single item, proudly self-declared "the most complex piece of machinery of all times". Which in my opinion should be an insult to any engineer, not a compliment. Rune. So in the end I guess to follow your analogy, I would buy the vehicle I needed, and that would not be a 4x4 to go get groceries to the market next block.

This should perhaps be on the first page, but a good rule of thumb is to not trust the forum's attachment system: it's pretty broken. ^^' Instead, use some image hosting system to post links to you images (or the BBC code to display them), and another file hosting site for the craft files. I use imgur for pictures and mediafire for files, both free, but that's personal preference. Rune. And please, no links to your desktop

Well, simple doesn't mean easy. On the one hand, the fact that the mass is water doesn't mean you need any less mass, even though you use it for other ends (the astronauts can probably take as many showers as the recycling system can process). And second, nobody is 100% sure of how much is enough. On the one hand, there is the people that say that if you try this at a solar minimum, there is a good chance you can just brave it out without any shielding (close to the maximum career limits for astronauts, though). And on the other extreme, 10-20mT of shielding per square meter will let you have radiation levels lower then Earth's surface in the middle of a solar flare (useful for colonies making babies). An infinite range between those two, so pick how much you want. But a decent one is on the tens of tons order of magnitude, for small crews that can hang in a very tight place. It's just what Nibb31 and I were discussing, Mars landers and their weights. I already linked to one, but there have been dozens of proposed landers: NASA's Design Reference Missions usually sketch one, and there are plenty of other alternatives. If you want to go old school, Von Braun's winged landers (which are based on erroneous parameters for Mars' atmosphere) are very "Buck "Rogers". Mars direct goes one step (or several) further and lands the Earth Return Vehicle to fuel it with ISRU. Rune. But that's a tin can without radiation shelter to brave the 8 month journey in, IMO.

Sir, you have just independently re-discovered the currently accepted best method. You also use other mission consumables (like food), but water is the best because you recycle it (so you shielding doesn't get thinner with time). And when hit by radiation, neither hydrogen nor oxygen turn into dangerous isotopes (they don't turn radioactive, in layman's terms). Just make sure it stays distilled pure water, any metal impurities on it will turn into nasty stuff. Rune. Nothing new under the sky.

Wow, that is a worst case, right? I mean, most Nasa studies put it between 50-100mT at entry (depending on what it exactly is i.e., Mars Direct's ERV, DRM's MAV, etc). The ascent capsule is usually closer to 25mT, propulsion included. Rune. I you want sources, I recommend Encyclopedia Astronautica. (That's the entry on NASA's Mars Excursion Vehicle, a 1967 study on Mars missions, <50mT)

I doubt the self-generated Auroras, since those are atmospheric particles getting ionized by radiation. Your spacecraft has no external atmosphere, right? But other than that, yeah, solar storms can kill people, but that is solved by putting mass (it pretty much doesn't matter what kind of mass, just the weight, so don't obsess with lead) between you and the radiation. The magnetic shielding is a much more exotic and less explored idea, and IMO a dead end: you end up taking up more mass with the powerplant than with a radiation shelter, and you still have no protection against neutron radiation (which is the one produced by, among others, the nuclear reactor powering the shielding)

Don't take this the wrong way, but you sound like a propaganda piece. I've heard very similar phrases from US politicians, and it is a shame they manage to sell the lie to anyone. The shuttle wasn't reusable, it was refurbishable. The only reason it flew 135 flights is a lot of engineers lived off it (and Boeing/Lockheed as mother companies). And 98.5% success is nothing to write home about, those are horrible numbers Soyuz can improve upon, both in percentage, in absolute number of deaths, in total number of transported people, and in cost to do so, per flight and total. And I'm cool the US is not trying to repeat their mistake and have gone the sensible, capsule way. But they are making other mistakes, forced by a myopic Congress. Rune. SLS, I'm looking at you.

The more you know... so only the turbopumps are made of their "adamantium"? Makes sense. Thanks!

Oh, but there are fancy tricks to go around that. And hydrogen has an awesome capacity to take away heat. That is why, at least on american engines like the J-2, it is used as coolant fluid for the nozzle and chamber. I don't recall what the russians do right now exactly, but they have metallurgy capable of handling oxygen-rich staged combustion, so I'd say they'd use oxygen 'cause it's netter coolant than RP-1. But that's because their pipes don't mind having liquid oxygen going through them at 500º. Rune. Which is like,

That is awesome. Can we get a closeup of the reloading mechanism? I may have to start looking into this... Rune. My post-exams period is starting to look busy

This looks awesome. I can't help on the programming side of it, but I will gladly test the hell out of it. Very gladly

Exactly. And if you do this at the center of rotation, the relative speed is minimal. The room itself is a nice place to get your bearings and can work double-duty as an airlock. It is bound to have maintenance benefits, at the very least. Rune. Now we could get into "why would you want hab space in a non-rotating section" part.

It looks so good with the panels down, I kinda wish you had done it RTG-powered. Imagine the part count...

+1 on pretty much everything you say here. But I do have a couple of things to say on what you say later... ^^' First, a space station doesn't have to cost as much as ISS did. Especially if its only operational requirement is having a certain number of crew. Depending on how much Bigelow charges, substantially less than a billion including launch costs and excluding operations cost. And Thales Alenia or Energia I'm sure would be willing to talk similar prices. Likewise the operations cost would be greatly reduced without the science and pioneering engineering, and all the hungry mouths to feed at the government side. In fact I think you can make greater cost saving than in launch vehicles right there. But even in launch vehicles an incredible improvement can still be made. Look at SpaceX, and the only thing they did is get a handle on their supplier prices by doing it themselves. Imagine if you had a market for true mass production, that could lead to some advanced projects (like Skylon, I like that one) becoming suddenly profitable. Rune. It's a chicken and egg problem right now, but you if you squint your eyes, can see dinosaurs starting to look like birds.

Forgetting for a second why you would want to do something like this, I'd say the easiest way would be to not need a seal at all. Use airlocks and "elevator cars" to move people around the joint, and maintain only mechanical connections to transfer loads. Even if both sides need independent life support as a result, that can be sen as a nice redundancy. Rune. "Elevator cars": Basically, you get into a room, it unhooks, starts spinning, hooks, and you step out after getting your directions back.

Well, considering the whole flight envelope, I still maintain my assertion. Lower ballistic coefficient also means less dedicated weight to lifting surfaces, for example, and those are dead weight in the rest of your flight. If you go for runway landing, which I don't think would be my first option, because rockets ain't airplanes. And having big tanks in an orbital stage means you can refuel it to reach high orbits, adding a lot of functionality. Reentry would dissipate the same heat over more time, making the engineering problem a bit more manageable usually, though it depends. Plus, breaking up the flight to orbit on three stages like the concept I outlined does provides bigger margins for structural and system weights overall. To balance that, you argue that ground effect and crosswinds make this option undesirable, and I just can't agree with that. It's a tiny detail that gets solved in other fields on a routine basis, IMO, not a show stopper. Rune. Are we the only ones still talking shuttles?

Hahaha, no witchcraft, plain chemistry. First you have to get Hydrogen, either from Earth or from water: 2H2O + energy > 2H2 + O2 Then you run a sabatier reactor: 4H2 + CO2 > CH4 + 2H2O Then you recirculate the water to the electrolisis unit. In the end, you have methane and oxygen, a good, only mildly cryogenic rocket fuel combination with isp's around 350-375. You could of course use plain water rockets, or go more complicated and build chemical industry on Mars. But methane is a really simple effective ISRU rocket fuel. Rune. Besides, it's just scooping up atmosphere, even though the compressor is far from trivial.

You did say something about "sporty landings", as I quoted. But anyhow, the fact is both airplanes and blimps manage to fly routinely with much better safety records than the shuttle could ever have. So being a better glider can only be good regarding reentry... as long as the "price" you pay for it is cheap. Which is why I still maintain that having fuel tanks on the orbiter and using it as the upper stage makes for an easier reentry, not a harder one. By easier I mean the weight fraction of the reentry-dedicated hardware will be smaller. Which is kind of the point. Rune. So better to have a tank already than putting wings on it.

Hum. I wonder how regular airplanes do it, then. Or blimps, if we take it to the extreme. And I've always been under the impression that low landing speeds were desirable, not a problem. Seriously, dude, really? It's amazing what a guy can say defending the shuttle. I mean it looks cool, but that won't change physics any time soon. Anyhow, some other thoughts about what is going on in the thread: Reusable SSTO is very, very difficult, and the jury is still out as to whether it is actually possible at all on chemical engines. Even if it is, the extreme engineering challenges might make it more expensive than other alternatives. Hell, we have yet to build a reusable staged launcher that works. Separating crew and cargo makes sense, because both payloads have wildly different requirements. Using the same launch vehicle for both, however, can rapidly build up a flight history, which increases safety and lowers cost (i.e: Soyuz). Hence my "same launcher, different upper stage" approach. And I don't think wings would be the most effective design solution, too, chutes are light, and you are taking with you engines with more than enough T/W for a soft land touchdown. Rune. My more than two cents, this topic fascinates me.

Develop a hydrocarbon first stage engine, that for starters. Use it to build a reusable first stage, and save actual money by trying to reuse the big part of the rocket that doesn't have to endure reentry and where weight increases are less felt. Don't get fixated on second stage reusability, but it would be a nice plus. Put the shuttle on top to avoid accidents like Challenger and Columbia, and give it its own tank to finish orbital insertion and engines capable of doing an abort. About three stages to orbit, reusing at least two, so easy on mass ratios to get that reusable hardware in. The first stage engines could go to die at the second stage with nozzle extensions at the end of their service lives. The empty fuel tanks and smaller engines on the orbiter would give it a better ballistic coefficient and thus a higher, longer reentry with less requirements on the TPS. I would probably pick something very storable for the engines, like hypergolics, and make provisions to refuel and/or transfer fuel to other crafts. Also solar panels for long flights. Main fuel for first and second stage would be either kerosene or methane, I think, whatever comes out cheaper. And most important of all, I would make it only to ferry crews and a limited amount of pressurized cargo. Big cargoes and satellites would go up in the same rocket, only with a disposable fairing and a reusable upper stage that can manage rendezvouses. That is a very important thing. Oh, and the "first and second stages" terminology I use might be misleading. I'd look at parallel staging them and doing some crossfeeding magic like in Falcon Heavy. Rune. It was called STS, and as a system it consisted of a lot more than the orbiter, but everyone focused on the wings.

I'd say it was more a problem of using a Saturn-class launcher to put an EELV-class payload in orbit. And that completely defeated its intended purpose of cheap frequent launches. If the shuttle had become a 25mT reusable launcher with 25mT reusable crew and cargo options, it might have been what it was meant to be. Instead it was a partially refurbishable behemoth with an awful flight rate, payload, and crew safety. However brilliant the engineering behind the shuttle was, the design concept was flawed from the start. Rune. Probably because a politician did it.

I steal from the best. BTW, I'm planning on stealing from you as soon as I get back to my gaming rig in the design of a kethane refueler truck. Rune. Because imitation is the greatest form of praise.

Oh, I don't know if you got what I said: I mean landing legs so it can land vertically tail-first on airless worlds, nothing to do with tail strikes on takeoff (though you get a strongish part that hits before others, that can save your bacon sometimes). Sure, the look is not as clean, but three heavy-duty landing legs can do wonders once you want to go somewhere else, and they don't weight much. You know, to exploit the large pure-rocket delta-v once refueled. I've got to do something like that to the K-33, and perhaps that will be a perfect opportunity to test it out without jets. Rune. And thanks for the praise! It is always welcome