Northstar1989

There's nothing unrealistic about Orion. Let's go through the issues one-by-one, shall we? That's absolutely not true. You can't constrain an argument to two false choices like that- it makes your entire argument invalid. But ignoring that... Atmospheric nuclear blasts are a non-starter, are they? You're forgetting that far, far more nuclear devices (and a much greater explosive tonnage) were detonated above-ground by the US and USSR during the Cold War before the Nuclear Test Ban Treaty- so that argument holds no water. With the kind of tonnage an Orion could lift to orbit, you could end the world's energy problems with a single launch (with a set of giant mirror-based concentrating solar power satellites and associated Microwave Power Transmitters), send enough payload to Mars to build a 100-person permanent colony/research station (or 50-person with a temporary but long-term stay and return trip), or launch a hypergolic-fuel depot large enough to fuel decades of manned mission to other planets. And all for a REASONABLE cost... (the lack of thin payload mass margins margins means you could build craft to the same engineering standards as a submarine) But, let's say you really CAN'T get politicians of the world to agree to allow atmospheric detonation of nukes (and an exception to the Nuclear Test Ban Treaty) for one of these noble purposes. What then? No, it really WOULDN'T take hundreds of launches. As already discussed, the 10-meter variant could be launched on a single suborbital trajectory by a Saturn-V, Nova, or SLS rocket. You don't need to give the Orion the 10+ km/s of Delta-V to make it to orbit: you only need to give it the 1000-1200 m/s or so of Delta-V necessary to escape the atmosphere with a straight-up launch. After that, the Orion is perfectly capable of propelling itself to orbit without any atmospheric nuclear blasts. And even if you couldn't get the funding for a ultra-heavy lifter, you really wouldn't need to engage in orbital assembly. Simply launch an Orion with an empty magazine of nuclear charges (this is a large portion of the system's weight), and launch the nuclear charges on a separate trio of launches to rendezvous and transfer over the nukes (in a zero-G environment they really DON'T need to be handled all that delicately) one magazine sub-rack at a time (this variant of the Orion would have the racks built in 3x symmetry, with a central feeder mechanism.) For a total of 4 heavy (but not ultra-heavy) launches, using existing launch vehicles, you could assemble a small Orion in orbit with no actual construction- just the attachment of 3 nuclear charge racks to a central feeder mechanism (alternatively, you could build the empty racks into the empty Orion, and transfer over the nukes one at a time...) The engineers who build Orion already worked out techniques to mass-produce sufficiently cheap warheads. That's why the majority of the files regarding Orion are still Top Secret. You are not the ultimate authority on nuclear pulse rocketry. Did you consider that perhaps people would like to discuss this topic WITHOUT your troll- errrr, domineering posts taking over the thread? Regards, Northstar

It's ironic that you criticize Constellation, because if I'm understanding you correctly, what you're suggesting is basically the Constellation mission framework. Constellation, which was similar to Mars Direct (and the subsequent Mars Direct-inspired NASA Design Reference Missions) in many ways (but less efficient, as I'll explain why shortly) basically had the following mission components: Mars Transit Vehicle- The stage that would leave Earth orbit, carrying the astronauts to Mars- where it would make a landing on the Martian surface after an aerobraking pass. This stage was typically large in most versions of the mission (and there were several- Constellation was actually a group of similar mission plans rather than one definitive plan), and as such would need to land on its "side" relative to the direction that was "up" on take-off from Earth atop an Ares V rocket. Earth Return Vehicle- This large stage would be launched to Mars, where it would perform an aerobrake-assisted capture (significant amounts of active propulsion would still be utilized, as the aerobrake would be very high in the Martian atmosphere to keep re-entry heat low) and would wait it orbit to ferry the crew back to Earth. This stage was designed purely for extra-atmospheric use, and would never land again after being launched from Earth's surface. Launched on a separate Ares V rocket from the Mars Transit Vehicle. Martian Ascent Vehicle- Basically a small lander that would ferry the crew between the Martian surface and the Earth Return Vehicle. In many versions of the plan, this lander would not be large enough to able to carry the entire crew in one trip, but would need to make two or more trips between the landed Mars Transit Vehicle and the Earth Return Vehicle waiting in orbit (it would refuel on the surface after returning from the first trip, and pick up the rest of the crew). Often the mission plans would launch this as part of the Mars Transit Vehicle- so it could equally well be thought of as the ascent stage of the Mars Transit Vehicle rather than as a separate craft. Mars Surface Mobility Vehicle- Like the Mars Ascent Vehicle, actually launched as a part of the Mars Transit Vehicle. Basically a 2-man pressurized rover (the Mars Transit Vehicle carried a crew between 4 and 8, depending on the mission plan variant). Mars HAB Module/ Surface Infrastructure- I list this as a combine entry because in many versions of the plan, these components would all launch atop the same Ares V rocket These components would include additional living space and supplies for the crew during their extended surface stay (for the mission plan variants that were more than flag-and-footprints), a power supply (variously solar or nuclear in different mission variants), and in some versions In-Situ-Resource-Utilization equipment to derive Meth/LOX rocket fuel and breathable oxygen from the Martian atmosphere (in some mission variants, the Mars Ascent Vehicle would even carry some of this Meth/LOX up to the Earth Return Vehicle, which would in those versions be waiting mostly-empty in orbit except for very limited amounts of fuel with contingency equipment... Otherwise, this fuel would only be used for the Mars Ascent Vehicle- though this at least meant mass savings on a smaller ISRU reactor and power plant...) At least one version also included a backup power-supply (based on RTG's) and additional scientific equipment. By the way, how many Ares V launches are we up to already- three? And we haven't even included the 3 Transfer Stages for each of the above payloads, which brings it to 6 total launches... But wait, there's MORE! Orion Crew Capsules- Because the mission clearly wasn't already heavy/expensive and bloated enough, the mission designers for Constellation decided to launch the crew on entirely-separate Ares I rockets in not one, but TWO or more Orion Crew Capsules (even though the crew capsule would only need to hold the astronauts for a few hours before rendezvous with the Mars Transit Vehicle in Low Earth Orbit, and using a single heavier capsule with additional seats would have been much cheaper/easier). They could of course have always launched the crew aboard the Mars Transit Vehicle in the first place- which would be designed to hold the crew under high G-forces (during Martian re-entry/landing) anyways- but apparently that would have been too efficient, and would have made the Orion Capsule designers very unhappy... One of these Orion Crew Capsules would have hitched a ride with the Earth Return Vehicle to Mars orbit (you know, it really beats me why they wouldn't have just left it in LEO), and the other would have (quite wastefully) been de-orbited... (OK, I'm being a little cynical about the need for the Orion. The Orion Capsule would be utilized to return the crew to Earth's surface upon returning to LEO instead of riding the Earth Return Vehicle down, which would have been very risky/dangerous and difficult to heat-shield with a vehicle that size. With a fresh transfer stage, technically the Earth Return Vehicle could have been re-used, and even ferried fresh crews to Mars orbit to rendezvous with the Mars Ascent Vehicle which would be left behind in Mars orbit: as the ERV would be left in a stable parking orbit above Earth after the mission...) So, we're totaling 3 payloads that each require an Ares V launch- plus a separate transfer stage (also launched atop an Ares V rocket) that would dock with in in LEO- as well as 2 Ares I launches for the crew capsules for each mission? (with only a slight possible re-usability for the ERV) Mars Direct, by contrast, only required two Ares V launches per mission (with no separate transfer stages to my knowledge!) although the crew would have been smaller (3-4 people) and had to deal with MUCH more cramped conditions... The major mission design differences that saved mass on Mars Direct: (1) Greater utilization of ISRU capabilities- use of ISRU fuel for the production of ALL fuel beyond what was needed to get to the surface of Mars. This meant all of the vehicles could arrive on Mars empty- including the Earth Return Vehicle (which would launch with its return fuel onboard in most versions of Constellation). Slower production of fuel (due to a longer stay + the ISRU reactor being launched earlier before the manned mission component) also required a smaller reactor and power plant. (2) The Earth Return Vehicle would also serve as the Mars Transit Vehicle- the same living space would act as lander, surface base, and return vehicle for the crew (though an additional HAB module would still be launched). Sure, it meant a rather heavy ascent stage compared to having a separate Mars Ascent Vehicle (something a NASA engineer criticized it for in the video), but it also meant you didn't need separate living spaces for your surface stay and your return to Earth... (both of which would need to be quite large for anything more than a flag-and-footprints mission) This was a MAJOR mass-saver on Mars Direct vs. the Constellation mission plans/ (3) No contingency equipment- one of the things that added mass to the Constellation mission plan which I hardly even discussed was its inclusion of contingency equipment. Basically extra supplies, (cramped) living space, and even fuel for an emergency early return-voyage to Earth with the tiny Orion capsule that would accompany the Earth Return Vehicle to Mars acting as both a transfer stage and additional living space during the long return-voyage. Fortunately, at least the Constellation mission designers had SOME sense when it came to this aspect of the mission plan- not only was the contingency equipment remarkably lean when it came to mass, (in some mission versions) it would also be left in Mars orbit after the first mission, and not launched again with subsequent missions unless it was ever needed and used up by one of the missions. (4) Lower-energy Mars transfer. This one should be relatively simple/intuitive for any KSP player. The Mars Direct mission plan called for a minimal-energy (Hohmann) transfer, which would take 6 entire months. The Constellation Mission Plan, by contrast, made use of a shorter transfer that required more fuel: 2-3 months transit time if I remember correctly (though it must be pointed out this would require less than twice the fuel- the Oberth Effect, which derives from E = 1/2 mv^2, whereas Delta-V is proportional to burn time, means that a rocket with a 50% higher Delta-V expenditure near Earth would acquire a *LOT* more than greater 50% energy. Thought of a different way, the faster you leave Earth's SOI, the less time its gravity has to pull you back in, and the faster you make the Earth-Mars transfer, the less time the Sun's gravity has to slow you down...) Of course, most players rely solely on minimal-energy transfers as time is meaningless to them with time-warp and no life-support or crew psychology requirements... (5) MANY other "luxuries", including but not limited to greater living space on the Constellation mission plans. The Constellation mission included things like toilets that made use of Mars' gravity and equipment to heat up meals, for instance, whereas Mars Direct relied on the kind of waste-in-a-bag and cold-soup diet utilized by Apollo astronauts if I remember correctly... Zubrin meant it seriously when he said the "travel light" part of "travel light and live off the land". Regards, Northstar

There would have been more catastrophic failures- and that would be fine. There would also be either more missions and more total goals accomplished, or more money for other purposes- such as foreign aid. It sounds like you're quite a cynic- and that's understandable if your impression of the space industry comes from companies like United Launch Alliance. There ARE companies taking big risks themselves though- like Space-X, or even Boeing (which has taken some relatively large risks with their Wave Rider spacecraft design, their proposals to NASA to build a Methane/LOX fuel depot in orbit near the Moon and help build the first generation of Meth/LOX engines, and their experimental spaceplane designs for the military) however. No, it's not. The whole point is that, if you look at the numbers, many NASA manned mission proposals could be performed for 2/3-1/2 their current NASA cost estimates by cutting out many of the fail-safes. The true cost of NASA's overly-high caution becomes even more apparent when you consider the justification for cancellation of some programs (such as the Ares I rocket) was that they couldn't be made sufficiently safe to satisfy NASA (for instance due to the risk to Launch Escape Systems from SRB rocket exhaust with Ares- the whole concept of a Launch Escape System being needless fluff far too expensive for the current generation of space tech...) The more than 50% increase in price-tag when NASA took a look at Mars Direct, and came up with their first Design Reference Mission should be just one example of the kind of excessive caution I'm referring to... One program being fat and inefficient, or a waste of money, isn't justification for another being fat and inefficient. And I must remind you that the US Mideast wars were actually useful from a certain geopolitical perspective. Poorly and wastefully-executed to the point of being counter-productive and actually harmful to US interests, yes- but not useless if performed correctly by any means. If Iraq had been carried out specifically to oust an insane dictator, with no lies about WMD's; and with better intel, heavier reliance on infantry tactics, and ground-based policing, rather than expensive bombing missions and high-tech gadgets; it could have actually been USEFUL to American (and other first-world) interests... But that's a separate point entirely. The fact is that money has a value. It can save lives. And spending hundreds of millions of dollars (and it really does add up to that much when you look at how much the safety systems add to total mission cost and complexity) to ensure the survival of a handful of astronauts is NOT worth the money that could just as well be spent ensuring the survival of hundreds of thousands of starving children in Africa, for instance. Manned Space Exploration is valuable and SHOULD be carried out. But it SHOULD NOT be carried out inefficiently and blindly, which is really part of the whole point of Mars direct. Regards, Northstar

Watched this documentary ages ago- don't really have the patience to watch it again. Mars Direct is a great idea- but the thing is, it achieves a lot of its cost-savings by cutting out much of the fat and extraneous safety systems from the traditional NASA approach to a Mars mission. Many NASA projects these days are gold-plated piles of *I won't say what* precisely for this reason. EVERYTHING has to have a million fail-safes installed, just because they don't want the PR disaster of a failed mission. And then, despite their best efforts, it eventually happens anyways. Most of the time, NASA would be *MUCH* better off taking an approach less obsessed with astronaut safety. Space Exploration is, and should be, a dangerous, risky enterprise. Any attempt to remove the risks is just stupid and misguided. Even from an ethical/moral perspective where lives are the ultimate good it's indefensible- the money they could save by cutting out some of their fail-safes could save far more starving children in Africa without access to clean water or healthcare (if the US government directed that portion of budget to the World Health Organization instead.) Regards, Northstar

The device "without modifications designed to produce thrust" was NOT a non-functional metal box. What it was: a resonant cavity WITHOUT slots cut into one of the ends to produce asymmetric refractive indexes for the microwaves. They still passed appropriately-tuned (resonant frequency) microwaves through the specially-designed metal cavity in both versions of the device. The necessity of these slots was the basis of some controversy- the original British inventor of the drive thought they weren't necessary, whereas the American (Fetta) who produced his own, slightly re-designed and re-named ("Cannae") version of the originally British EmDrive drive design included these slots- as he thought they would be necessary for the drive to work with some of the other modifications he made to it. The differences between the British version of the drive tested in China and the American version tested in China could easily explain the thousand-fold difference in observed thrust between the two experiments. The success of the slot-less drive confirmed that Fetta was dead-wrong in adding slots to the design- nothing more. The underlying drive appears to work perfectly well in either circumstance- which is what so many people who didn't do their research properly before writing criticisms of the drive wrongfully interpreted as "both the null and functional versions of the drive producing thrust". I'm more concerned (and you should be more concerned) about the fact that they didn't perform the test in a vacuum. The possibility of interaction with air inside the chamber to produce thrust is a perfectly valid possible explanation- although in that case, the RF-load control should have probably produced thrust as well, and it didn't. Regards, Northstar

Pendulum and torsion thrust-measuring devices are commonly used to measure ion engine thrust. There's nothing unconventional or unproven about the measuring equipment- there's a reason NASA had the equipment in the first place (it works). Aide from criticizing the motivation of the scientists themselves on rather fuzzy logic, the only REAL criticism is that the "null" and "experimental" devices both produced thrust- a criticism that popped up once on the internet, and seems to have been mirrored many times since. Unfortunately, what the people making that criticism did NOT understand, is that the "modification" (slots/roughening on the end of the device) was controversial in the first place. While Fetta (the American scientist to build HIS OWN version of the EmDrive and re-name it the "Cannae Drive") included these slots, and thought they were necessary, other previous versions of the drive included no such slots, and appeared to work perfectly fine. Thus, the "null" version of the drive (the use of the term null comes mainly from the critics, not the article itself) was not actually a null-version. It was an alternative, simpler version of the drive that was proven to work just as well. The ACTUAL null version of the drive was the "RF load" the abstract of the data talks about. THIS TEST was an actual null version of the drive designed to replicate the same electricity consumption, RF frequency emissions, etc., and produced no thrust- thus validating the test of thrust production. Being an actual scientist in real-life, with experience in an equally controversial area of research (Stem Cell Research- you could actually find my name in the scientific literature if you knew my real last name...), I can tell you from stories I've heard from a number of professors that critics have an extreme tendency to twist the words in your abstract to mean things they were never meant to mean. One little ambiguity, and it will be taken as proof that nothing you say is valid, if the reader doesn't want to believe your data/results. This is a VERY good reason to take the criticism with a grain of salt, just as the critics are taking the abstract with a whole boat-load of it... Regards, Northstar

The article is little more than stereotypical skeptic rage. It doesn't actually raise a single point about the data or science itself. All it does is take the author's arrogance in assuming a single friend of his at Caltech know everything (I've talked with actual elderly physics PROFESSORS, with a lot more experience in physics than his friend, who described the Quantum Vacuum in a way that made something like a Q-drive/EmDrive seem plausible years ago...) and combine that arrogance with a hefty dose of "if it's too good" pseudo-logic. I'm not saying the "Cannae Drive" that's been circulating the news will turn out to be valid/reproducible. In fact, it's probably less likely than not. But articles like that don't do anybody any good, and just muddy the water further. Good thing it was little more than an editorial. Regards, Northstar

You must remember that airplanes would have sounded too good to be true to cavemen. Clarke's Third Law: "Any sufficiently advanced technology is indistinguishable from magic." http://en.wikipedia.org/wiki/Clarke%27s_three_laws Regards, Northstar

Yeah, pretty much. If you want a higher energy-density for rocket fuels, why would you both powdering a solid fuel and creating a slurry? Why not use a LIQUID fuel, such as Kerosene/LOX? (which is already one of the main fuels for rockets- and has a much higher energy density than LH2/LOX despite lower ISP) We already know how to turn coal into petroleum products- the Germans have been doing it since WWII when they used it to fuel their tanks after western nations cut off their oil supply... Regards, Northstar

This thread is dedicated specifically to this documentary. Are there other threads on Project Orion? Yes, absolutely. But threads only have a limited lifespan anyways, and it's entirely unreasonable to ask me to go an dig up an old thread and necro it when there's plenty of room for new threads on this subforum... Regards, Northstar

I highly recommend taking the time to watch this BBC documentary on Project Orion (the nuclear-pulse rocket that is still the best, cheapest, and perhaps only way we'll even send large payloads to other planets) https://www.youtube.com/watch?v=VCszu4zaqr0 https://www.youtube.com/watch?v=VCszu4zaqr0 Feel free to discuss here your thoughts on this. And share the documentary on as much of the internet as you have the time- Facebook, Twitter, etc. I still feel Project Orion is mankind's best hope of ever colonizing the solar system, and not nearly enough people know about it. Regards, Northstar

I've only got sporadic pictures of my next bit of progress, but that's OK, because I have a perfectly good YouTube video uploaded of my Twitch broadcast showcasing my latest play session: Sorry about the resolution by the way- the recording was made at a much higher resolution (720p if memory serves). I'm going to have to look into why YouTube automatically downgraded it to 360p... Before the start of the video, however, I adjusted the periapsis of the LV-T45 Drive Section so that it could aerobrake into a lower Kerbin orbit: After that, the video picks up as I launched my Duna Probe atop a new, SLS-style SRB-based rocket: Subsequently, I docked the Space Taxi with the fuel canister I left in LKO earlier (when I launched the Space Taxi) and sent it on its merry way to the Mun: This wasn't super clear from the video, but my plan is to use the fuel carried by the space taxi to dock the Reusable Lander back up with the Munar Mobile Lab, and in the process transfer as much fuel over as possible for a future Mun landing (this time I'll have to head further from the equator, so it'll take a full fuel-load on the lander) while still leaving the Space Taxi with enough fuel to carry a Kerbal (probably Jendin Kerman, since Bob got the privilege of being the first Kerbal to set foot on the Mun) and the scientific data from the Mun landings back to Kerbin Anyways, after that, the LV-T45 Drive Section made its aerobrake pass on Kerbin, my Duna Probe made a burn to intercept it near apoapsis, and rendezvous+docking was carried out, followed by orbit-stabilization: I made up much of my plan as I went along, having been unable to nail it down beforehand, but I did get as far as deciding that the LV-T45 Drive Section would be a better choice for a transfer tug than the existing radial engines on the Duna Probe, as a LV-T45 has a much better ISP (370s) than a Rockomax 24-77 (300) or a LV-1R (290). The additional thrust should also be extremely useful for an accurate burn. Therefore, the three sections will proceed to Munar orbit as one unit (once a transfer window arises), where the LV-1R equipped fuel canister will detach and likely act as a fuel depot (the Mobile Munar Lab will eventually be departing for Minmus, and then Duna) in the short run, and a fuel-ferry between a larger depot and craft in need of refueling in the longer run (the very small engines should help keep fuel fraction high- making it optimal for very-low Delta-V hops between Munar orbits; while the low part-count will generate far less lag than bringing a very large interplanetary vessel within physics-loading range of a large Munar space station) Finally, the Space Taxi rendezvoused and docked with the Reusable Mun Lander, and will soon be moving with it the Mobile Munar Lab to pick up Jendin Kerman and the scientific data (once again, this is better-documented in my YouTube video). I hope you enjoy the screenshots: The actual rendezvous with the Munar Mobile Lab will have to wait until I can get a working installation of Kerbal Alarm Clock for 0.24.2 though. I haven't the patience to wait 30 minutes of real-life time for the combination to reach the optimal Maneuver Node 5 hours down the line at 10x time-warp (the maximum speed for that altitude), and there's a great risk of fast-forwarding through the node if I perform the time-acceleration at the Tracking Station instead... Regards, Northstar

Progress continues. First of all, the LV-T45 Drive Section got an unplanned Munar Intercept that stabilized its orbit so it will no longer enter the atmosphere of Kerbin. I guess I'll need to perform a more rapid aerobrake if I want this to work before the Mun comes around the next time... Second, I successfully recovered Ronlorf Kerman (and one of the Crew Capsules) from Kerbin orbit: Too bad the docking port, which survived all the way through re-entry (due to the VERY shallow re-entry trajectory, as well as some tumble I introduced into the re-entry to spread out the heat) ended up crumpling up when the command pod landed on the side of a mountain instead of near sea-level... I did manage to get some great contracts out of the recovery mission, though: Hello sweet LV-N's! Now my Kerbals will REALLY glow green! I apologize for the much lower resolution now, by the way. It appear that Active Texture Management is over-reducing the textures on 64x Aggressive mode in its current version. Now all my rockets look EXTREMELY bland- but I've never seen such a reduction in lag! Regards, Northstar

For those of you who didn't see the change to the front page of this thread, I've installed several new mods: Active Texture Management (Aggressive) - Without this I wouldn't ever be going beyond FAR and MechJeb Chatterer - this will make Twitch broadcasts (more to come, hopefully) a bit more interesting Deadly Re-Entry - This will make KSP more !FUN!. Luckily, my existing Crew Recovery Capsules are based on Mk1 Command Pods (which have built-in heat shields), and I haven't yet begun preparing any interplanetary missions... KW Rocketry - I caved and finally added a parts mod (as well as DRE). I'm interested to see how it compares to NovaPunch, which I'm more used to (although I do like NovaPunch's fuel-containing adapters). The 5 meter parts this eventually enables will also allow me to build rockets with better Ballistic Coefficients, which should allow me to utilize FAR to its full potential... More progress (and screenshots) to come soon, once I'm sure the new mods are working correctly. Regards, Northstar

@NathanKell A worked example for a pair of (tall) conical adapters using the same base price per square meter of Surface Area: 1.25 meter top, 2.5 meter base, 2.5 meters tall S.A. 17.48 pi m^2 Volume 9.766 pi m^3 Base Cost 1748 Funds 2.5 meter top, 5 meter base, 5 meters tall S.A. 69.90 pi m^3 Volume 78.125 pi m^3 Base Cost 7812.5 Funds Note that, as before, when the proportions are kept in the same ratios, but doubled; the volume increases by a factor of 8, but the surface area only increases by a factor of 4. The necessary thickness of the walls for the the total rocket (assuming wider stages are placed towards the bottom), meanwhile, can best be modeled as a very tall, thin cone that has a height equal to the rocket. The radius of the cone at any given point is proportional to the amount of structural material needed to support all the weight above that point. A cone works for the model shape (even though idealized structures have a slope that gradually decreases towards the base) because real rockets are built to designed safety margins- and the statistical error of deviations in construction becomes smaller and smaller in absolute terms the thicker the thicker the walls/ larger the structure. Plus, real rocketry materials are so strong the change in slope is relatively small over the height of the idealized model to begin with. It would be different if you were building out of something like soap or soggy cardboard. It should quickly be noted that the upper third of the cone only contains only a tiny proportion of the total structural material, whereas the lower third contains far more material than the two upper two thirds combined. The degree of taper of the cone is proportional to the strength-to-weight ratio of the material. However, the effect of increasing wall thickness on fuel tank cost with any reasonable-sized rocket is relatively trivial- especially since the cost-per-mm does not increase linearly (thinner walls are relatively much more expensive to construct per kilogram of material than thicker walls, due to manufacturing costs.) Players using larger-diameter fuel tanks for the upper stages of a rocket also cannot be taken for a given- perhaps a player is launching a large, EMPTY fuel depot, for instance- which will only be filled in zero-G. And the strength the rocket needs to be built to increases with its TWR. Plus, on top of all this, real rockets make use of advanced composite materials and structures like honeycomb-walls that have strengths that are different from that of the underlying material (Metamaterials, basically), so it's probably not worth trying to work through all the possible complexities. All in all, I think it's best to ignore the effect of increasing wall thickness with part diameter on rocket cost. I would be more than happy to help you figure out/implement the proper equations to apply for price and mass-scaling for each of the different shapes available in Procedural Parts (PM me if you're interested in my help). One of my best subjects was Geometry back in my high school days (though I've now graduated from Graduate School). Regards, Northstar

@NathanKell I apologize if this has been asked too much for your liking- but did you eventually figure out a way to implement some sort of procedural cost for this mod in 0.24.2 Career Mode? It looks like RealChutes mod has managed to implement procedural part costs somehow (as of its July 27th update- based on part mass and canopy size), so it might be worth looking into if you haven't managed it yet for this mod: http://forum.kerbalspaceprogram.com/threads/57988-0-24-x-RealChute-Parachute-Systems-Procedural-cost!-v1-2-3-27-07-14 The most logical system to me would seem to be to base the base cost of the fuel tank on part dry mass, and the dry mass and fuel capacity on the Square-Cube Law and the geometric laws governing change in surface area and volume for various shapes (this is IMPORTANT- a 5 meter fuel cylinder has a MUCH better fuel fraction in real life than a 2.5 meter cylinder due to the Square-Cube Law!) A 5 meter tall, 5 meter diameter fuel cylinder compared to a 2.5 meter fuel cylinder of the came proportions (one with half the diameter and height), for instance, should have 4 times the surface area (and thus dry mass and cost), but 8 times the volume! (and thus a better fuel fraction) So, to use arbitrary numbers, but with the proper geometrical equations; if the Base Cost were figured as 100 Funds per 3.14159 square meter of surface area: 2.5 meter cylinder, 2.5 m tall S.A. 25 pi m^2 Volume 15.625 pi m^3 Base Cost 2500 Funds 5 meter cylinder, 5 m tall S.A. 100 pi m^2 Volume 125 pi m^3 Base Cost 10000 Funds This ignores the factor that the walls of the 5 meter cylinder would probably be thicker than that of the 2.5 meter cylinder, of course- but they wouldn't need to be twice as thick (for the same strength and safety factor in engineering), so the larger cylinder would still be cheaper/lighter per cubic meter of volume! Regards, Northstar

I'm still hoping you'll update this for 0.24.2, and give it a price-tag to scale. Just keep in mind that this was a "Big Dumb Booster", so the whole point of the thing was much lower cost-per-kg to orbit than traditional rockets. Regards, Northstar

Alright guys, so it was an awesome run as a Thread of the Month for July, and I thank everybody who posted on it. Since I expect discussion to considerably die down from here, I figure I'd sum up the issue as I see it. Basically, it boils down to this. Rockets that can carry things to space are big, EXPENSIVE machines due to their very precise engineering margins- despite there being no inherently high cost in the actual technology they involve (rocket engines, for instance, are actually CHEAPER, lighter, and more powerful than jet engines built to the same level of precision of a comparable size). This leaves 2 solutions to get large total payloads to Low Earth Orbit: (1) Build an EVEN BIGGER rocket, with lower precision in construction but much greater safety margins, to get the same payload to orbit much less efficiently. I.e. like the Sea Dragon- which would have been SEVERAL times the size of the Saturn V, but the payload to Low Earth Orbit was relatively much smaller due to the much larger safety margins. Such rockets are actually more reliable than traditional "Smart Boosters" due to the higher safety margins, and the potential to utilize large rocket engine clusters (think 21 nozzles of thrust- 3 of which could fail on any given launch) or just a single huge rocket engine with enormous safety margins. This is the "classic" Big Dumb Booster approach. (2) Build a CHEAPER rocket- one in which the precision of engineering is low (allowing these rockets to fit the "dumb" part of "Big Dumb Booster" despite their small size), but the safety margins are similar to a "Smart Booster". This will lead to FREQUENT launch-failures, but unlike the Sea Dragon, you only use this style of rocket to lift payloads with low inherent value- like fuel, food, and toothpaste for astronauts. This is the "Bread Trucks were used to move Bread, not Brinks Trucks" approach to rocketry. You still need an alternative style of high-reliability rocket, such as Big Dumb Boosters styled after the Sea Dragon, to lift high-value payloads: such as live astronauts, valuable scientific instruments, and EMPTY interplanetary vessels or probes (you lift the fuel on Cheap-O-Fail rockets like the ones just described). The classic rocket in this category is the Aquarius- which would have amortized the launch failure rate approaching 1 in 3 over many launches through a small payload capacity of only 1-ton-to-orbit, and avoided risking damage to ground launch facilities or space infrastructure through sea-launches and a specialized depot to collect the supplies of multiple launches in orbit (before transferring them over to more expensive space stations like the ISS via orbital tug). Both styles of Big Dumb Booster had much lower cost-per-kg to orbit that "traditional" Smart Boosters. Both would have had their own unique niches where they performed best (Aquarius for launch of consumables and fuel; Sea Dragon for launch of heavy, expensive payloads that you simply can't afford to lose- it would have been more reliable than a "Smart Booster"). Both would have had drawbacks- a high designed launch failure rate (and thus bad PR) for the Aquarius, a low mass-ratio for the Sea Dragon (a rocket several times the size of Saturn V, yet much cheaper and with only slightly larger payload capacity). Though, IMHO, the drawbacks of either would be well worth the benefits- as these rockets would be BY FAR the cheapest way to get mass to orbit, even today with the days of Space-X reusable rockets rapidly approaching. Regards, Northstar P.S. For those interested, somebody actually made a working Sea Dragon mode for 0.23.5 http://forum.kerbalspaceprogram.com/threads/84810-Official-release-of-my-SeaDragon-mod!

Just a quick update here... Recently, my Space Taxi/OTV rendezvoused with another stranded Kerbal and brought him aboard. It is now waiting for a transfer window to one of the two orbiting Crew Recovery Capsules (I'll have to launch another one for the recovery of my Munar Mobile Lab's crew...) Also, the LV-T45 Transfer Stage performed another aerobrake through Kerbin's atmosphere. As it's running out of ElectricCharge, it will have to perform a retrograde burn at apoapsis to speed the whole process up next time around... Oh, and finally, my fourth YouTube video (showing my first Mun landing) is now up: Regards, Northstar

You can always "Build It Bigger". You have to remember we're not talking just one individual capacitor- at that scale we're talking rows and rows and rows of capacitors in an underground complex. We do that kind of thing all the time for the largest particle-colliders... (and for experiments into fusion power- the National Ignition Facility was used as the set for the warp core of the Starship Enterprise in Star Trek: Into Darkness, for instance) Regards, Northstar

There are a few contracts that are extremely lucrative, yes, but in general you'll find it hard to just cut it even once your Contracts start taking you further out than just Kerbin/Mun/Minmus. The problem with most player's early perceptions of cost is that they don't realize that Squad has intentionally given us an early buffer in terms of cost/reward so as to help new players get used to the game and allow for many early failures. Once you start progressing beyond the Kerbin system (heck, even once you start to get to Mun landings), the Contracts become extremely difficult to cut something as high as a 6:1 cost margin on. You've got to remember it doesn't matter how much money you have in the bank- it matters how much you make/spend for whether you'll eventually go bankrupt. Thus if costs start to consistently exceed income with a 6:1 cost modifier mod like this, you WILL eventually go bankrupt even with that early-game buffer. All this ALSO assumes you don't intentionally/deliberately cheat or exploit the Contracts system- for instance leaving probes in orbit around celestial bodies just to cheaply pick up the "Transmit/Recover Data" contracts- instead of launching a new probe for each Contract... Regards, Northstar

I believe you mean *breaking* the mod with incredibly excessive and over-inflated part costs (25,000 Funds for a simple, dumb, low-temperature, no-magnet metal exhaust cone on a 1.25 meter beamed-power thermal rocket). Did you read any of the discussion I had earlier about the current costs for Microwave Beamed Power Thermal Rocketry (which should actually be CHEAPER than chemical rockets in terms of the parts you actually launch for balance- as the whole point of Microwave Beamed Power is to leave the heavy/expensive parts behind- and to correspond to reality- at the cost of incredibly expensive reactors and transmitters that actually generate the power- which I assume most players will run from the ground now that 0.24 makes launches so expensive...) Regards, Northstar

I did a face-palm reading this. Did you actually read anything I wrote before? I'm talking about use of beamed power for Thermal Rocketry- which is perfectly "decent" in terms of ISP (better than chemical rockets). Apparently you've grown accustomed/spoiled from using some of the more OP'd features of KSP-Interstellar. My whole entire point was that those features should be expensive, but earlier technologies like Microwave Beamed Power Thermal Rocketry, in particular, should NOT cost tens or hundreds of thousands of Funds just for the parts on the actual rockets (as opposed to the reactors and transmission-facilities, which SHOULD be expensive...) Regards, Northstar

I also performed the Munar injection of my Munar Mobile Lab last night. Here are the screenshots from that: These screenshots correspond loosely to my second uploaded YouTube video: The volume is still a bit off, though better than in the first video for at least some of the beginning of this one... After Munar injection of my Mobile Munar Lab, I followed that up with Munar injection of my Reusable Lander as well: That went extremely well- I was lucky enough to get a very rapid rendezvous with the Muanr Mobile Lab soon after circularization. Here's a link to video #3, by the way, where I transfer the Reusable Lander to the Mun: Then I performed my first Mun landing! (video #4 shows this- being uploaded now) And ascended back to orbit to refuel, transfer over the science, and clean out the used experiments... (this was my first time using a Mobile Lab to do either, so it was a learning experience...) And then performed a second Mun landing (this time near a Mun arch!) During this Munar sortie, my Kerbal (Jendin Kerman- Bob having had the opportunity to perform the first landing) jet-packed over to the Munar arch (not shown here, but visible in my fourth videos), and collected some !SCIENCE! under it. Unfortunately, and surprisingly, there was nothing particularly unique about the arch from a scientific standpoint; and my Kerbal used up so much EVA Propellent on the way there that he had to hike most of the way back, which took a LONG time... Jendin did eventually make it back, though- and proceeded to take off for the Munar Mobile Lab and ANOTHER refueling + scientific analysis sortie: It occurred to me while doing this that once I install TAC Life Support before my first manned mission to Duna (which is on my to-do list), I might be better off, when returning my Mobile Lab to Kerbin at the end of the mission, performing this kind of analysis of samples on the way BACK to Kerbin, as it takes a long time... I probably won't be leaving the lab at Duna unless I decide to develop ISRU life-support facilities there with locally-powered greenhouses, as the life-support requirements of a two-step transfer stopping at Duna to locations further out, such as Jool, would be ENORMOUS- due to the much longer mission time... I then suited up Bob Kerman again, and performed a THIRD (and final- until additional fuel can be sent to the Mun) Munar landing: I had about enough fuel for one-and-a-half Mun landings at this point, though- so I decided to push my luck, and made a suborbital hop to another nearby crater of interest for additional !SCIENCE! As you can see, though, that left me with a VERY tight Delta-V budget (it would have been less tight if I had brought a bit less fuel on my initial Munar landing- but I didn't know precisely how difficult it would be to land with this particular lander design, and wanted to be safe rather than sorry...) So I ended up only having enough fuel to launch the lander back to an extremely low inclined Munar orbit- from which point Bob Kerman collected all the science, bailed out, and jet-packed over to the Munar Mobile Lab on his own... (no pictures shown of the actual maneuver, though I *think* you can find footage of it in the Youtube video uploading right now...) I hope you guys enjoyed this mission set (there will be more once I manage to send some additional fuel over on my OTV/ Space Taxi), and remember that you can follow me (or subscribe to my channel) on Twitch or watch my videos (and subscribe if you want) on YouTube! Regards, Northstar

OK, so I don't believe I had many viewers for my play session last night, but I have at least gotten the hang of how to broadcast to Twitch a little bit... I'm still having issues with the sound level being messed up and stuff like that, and running Open Broadcaster Software (OBS) lags the heck out of my computer- but it's better than nothing... Hopefully, I'll figure out ways to tweak and fine-tune my broadcasts in the future... Anyways, I also took screenshots of my launches for the rest of you guys. Here are the shots of the launch of my "Space Taxi" My "Space Taxi" will serve as my specialized Orbital Transit Vehicle (OTV) between specialized 1-Kerbal Crew Launch/Recovery Capsules launched to LKO (atop the semi-reusable SRB launch vehicles shown previously) and other orbital craft (such as interplanetary transfer vehicles) and installations- such as my Munar Mobile Lab (which will act as a permanent station for new Munar landings until I've exhausted all Science there, and after which I've decided I will re-deploy it to Duna instead of recovering it...) It will also double as an orbital tug for light payloads traveling to the same destinations as my Kerbals- such as Munar orbit when sending fresh crew to my Munar Mobile Lab or recovering previous crew members... I also used my Space Taxi/OTV to de-orbit Pomeroy Kerman for a Rescue Contract, and replace him with Bob Kerman for my Mun mission: Finally, for those of you who missed the front page, I'd like to let you know you can watch a video of all this I posted to Youtube at: This video is just the beginning of a series of videos I'll be posting following my 0.24 Career Mode progression. I have 3 videos up so far, and a 4th video is in the process of uploading as I write this. I apologize for the sound levels being so imbalanced in the first videos (you can't hear my voice much of the time over the music or sound of rocket engines, due to my computer's use of an internal microphone and internal speakers- and even when you can hear it, it sound very different than in real life), but that will be something I'll focus on improving in the future... Regards, Northstar