GreenWolf

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About GreenWolf

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  1. GreenWolf

    Circling Minmus in a Cricket -- "We found Santa."

    @cratercracker Oh man, that's super neat. Might see if I can find a way to edit that onto the shoulder of their EVA suits without changing the overall mission flag. I've been out of town most of the last week, but updates should resume tomorrow/this weekend. Want to see if I can maybe get all the way to the south pole by Sunday.
  2. GreenWolf

    Circling Minmus in a Cricket -- "We found Santa."

    INTERMISSION Mango Resupply Mission (Full album link.) I finally had some more time to play KSP last night, so I set about resupplying our prosaic polar pals. After some conferencing with mission controllers back at KSC, it was decided that, in addition to carrying a full can of spareparts for the Cricket, the Mango Cargo Lander would also bring up two boxes of rocket parts, which would be used to assemble 4 ground relay stations on the far side of the moon. (These ground relay stations will form the first part of a circum-minmusian ground communications chain, which will be expanded later by several seismic probes being sent out in the next launch. But more on that later.) After quickly fabricating the necessary parts in the Minmus Workshop Module, Obgas (Auxiliary Engineer) and Tanly (Lander Pilot) packed them into boxes and shoved them into the hold of the Mango. Then they took off for the north pole. (Important note: The Mango has enough delta-v to boost into a ballistic trajectory and land at the north pole, but won't have quite enough delta-v to do the return. Instead, it will boost into a low polar orbit and rendezvous with the Apricot Fuel Tanker [which itself will be sent down to Minmus Base to fill up, and then launch into a polar orbit]. Obgas and Tanly will spend the time waiting for the Apricot doing some long-term observations at the pole, or something.) A few minutes later, and they were landed half a kilometer from the north pole. And to think, it took me all that time to drive here. Assembling MGR-1 (Full album link.) Once Tanly and Obgas were landed, Virburry drove the Cricket over to greet them, taking care to keep the Mango in the safety of the Cricket's shadow shield. Wouldn't do to accidentally irradiate your resupply mission! Virburry: "Look Patzor, we found Santa." Patzor: "Funny. Try not to crash into them, maybe." Virburry: "I would never run over Santa with a rover. He probably has a separate list just for that." The two crews got out of their respective vehicles, and after a quick exchange of greetings, set to work. First, the Cricket would need to be retrofitted to carry the cargo boxes, at least temporarily. After a short argument with Patzor over the placement of the new cargo racks, Obgas bolted them into place. Then the two of them brought the supply boxes over from the Mango and mounted them on the new cargo racks. Virburry and Tanly watched from atop the Cricket. Obviously practicing their management skills. With that out of the way, they set to work assembling the first ground station nearby. (Which did necessitate bringing one of the cargo boxes over to the construction site.) Tanly: "Wow, that thing fit inside one of those boxes? How the heck?" Virburry: "It's an ancient engineering technique called IKEA, primarily used for creating flatpack furniture. I did my thesis on applying it to space construction." Tanly: "Huh. Neat." Up next: Heading south.
  3. This is your problem. 95% of what you are taught in high school physics, up to and including Newton's laws, is wrong. Not wrong in the sense that it is completely incorrect, but wrong in the sense that it has since been superseded by modern theories that are more correct. It's important to understand that all scientific models of the universe are descriptive approximations of how we think the universe works based on the observations that have been made, and that new observations can subsequently overturn previous models that fail to account for them. So Newtonian physics is a model that explains the observations that were available to Newton at the time, but failed to adequately explain later observations (most importantly, its inconsistency with Maxwell's equations of electromagnetism). Special relativity was formulated as a new model to replace Newtonian mechanics (and was itself later superseded by general relativity, which extended relativity to include gravitation). But the current theories (general relativity, quantum chromodynamics, etc...) aren't taught in high schools because they require mathematics that, for various reasons (most of them stupid), also aren't taught in high school. So the older theories are taught instead, because they're considered "close enough" for the needs of most laymen. (And indeed, even in physics, we still use Newton's laws as a first-approximation for non-relativistic motion.) The take away from all of this is that you can't apply Newton's laws in a relativistic frame work. It don't work like that. As for an actual answer to your question, it specifically comes down to the fact that at relativistic speeds, F does not equal ma. More specifically, because of mass-energy equivalence (the ever-so-famous E = mc2), as an object with mass gains velocity, it also gains (relativistic) mass from its kinetic energy, which means that you need more force to accelerate it the same amount. The faster you get, the more mass you gain, the more force needed to accelerate, increasing asymptotically as you approach the speed of light. What this means is that you can approach the speed of light, but never reach it. Photons can travel at c because they have no rest mass. (They do, however, still have energy, and thus momentum.) (Also, photons don't accelerate. They're always traveling at light speed.) Other than the impossibility of accelerating an object with mass past the speed of light though, there's nothing specifically preventing you from traveling faster than light. Although if you did, it would violate causality, but to explain why I'd need some more time to prepare diagrams. And also probably some calculus.
  4. GreenWolf

    Mars Colonization Discussion Thread

    Planets are a distraction. I expect all of you are familiar with the extreme delta-v requirements necessary for landing or launching something on a planet.So I'm going to pose this question: If you have the technology to create a closed-cycle life support system that is self-sustaining (or needs only a relatively small amount of occasional materials inputs) and capable of indefinitely supporting human habitation in space, why would you go to the trouble of building it on the surface of another planet, which would require you to haul everything up and down two gravity wells and across vast interplanetary distances? Gravity? Well, Mars doesn't have very much of that in the first place, and it's trivial to build a counter-weight and tether system to provide centrifugal gravity. Minerals? Maybe, but anything you can get from Mars, you can get far more easily from asteroids. In fact, there's a lot of things you can get from asteroids that you can't get from Mars, like phosphorus. Water? Same deal as before, get your ice from comets and asteroids. Radiation shielding? Here Mars has a slight advantage, in that it has more space available to put stuff beneath several meters of rock. But it's not too hard to add some layers of shielding to a spacecraft. If you really want to go the distance, you can hollow out an asteroid and use that as your living space. There is nothing on Mars or which can be provided by Mars that cannot be obtained more easily from small-mass asteroids. Colonizing planets is a foolish distraction, the idea of which is only kept alive by naive romanticism. We should be focusing on building arkships and asteroid habitats, which pose far fewer engineer challenges and have the added benefit of being mobile. (Or mobile enough that we could set one [or two, or three, or a hundred] up to slowboat out of the solar system, thereby ensuring the continued survival of the human species, even if, say, a gamma ray burst scoured the life from every planet in the system.) TL;DR: Mars ain't the kind of place to raise a kid.
  5. At the risk of getting slightly off topic, it's not nearly as simple as that. The mechanics of orbiting tethers are non-Keplerian, and at best only marginally well understood. But it is known that a tether of any significant length is not going to be following a normal Keplerian orbit, and in most configuration is highly unstable. It's a result of the ends of the tether orbiting at different altitudes, and thus different speeds.
  6. GreenWolf

    Everyday Space Drives

    Then they aren't comparable to or competitive with NTRs (which was the initial context they were brought up in) since one of the biggest advantages of an NTR is that it gets significant thrust and specific impulse. Also, nothing with humans onboard is going to do Earth/Mars transfers at milligee accelerations, because it would take literal years. Except that's not how orbital mechanics works. That 2 km/s figure is for a Hohmann transfer, which requires you to burn at a specific phase/ejection angle. But if you're burning on the sunward side of Earth, your ejection angle will be almost 180 degrees away from where it should be, which will require you to perform expensive correction maneuvers in deep space, which massively increases you transit time and delta-v requirements, effectively losing any propellant savings you might get from having a higher exhaust velocity. You'll run into a similar problem at the other end when you reach Mars, essentially having to match velocities with the planet before you get into its SOI and then gradually getting closer, so that you can actually perform your insertion burn once you get into the SOI and not just fly off into space again. The long spiralling trajectory that the Dawn probe took out to Ceres is a good example of what your actual transfer would look like. There already exist a number of civilian sea-faring ships that are powered by nuclear reactors, and most nuclear power plants are operated by civilian contractors or companies. Considering the ease of tracking things in space, and the difficultly of launching things, it'd be pretty easy to regulate nuclear reactors in space.
  7. GreenWolf

    Everyday Space Drives

    Mylar is a pretty terrible structural material though, and if you want your mirrors to hold up under acceleration, you'll need to reinforce them with stronger -- and heavier -- structural supports. Additionally, your mirrors will still be absorbing some thermal energy from the sun, and that has to be radiated away (separately and in addition to any waste heat generated by the ship's electrical systems) which will necessitate more mass in the form of radiators. Also, that still doesn't address the planetary occlusion issue, which is a major problem if you want to insert into orbit -- you aren't going to be doing an aerocapture with a set of giant fragile wing mirrors attached, and orbital dynamics necessitates that the orbital insertion burn into a prograde orbit for a spacecraft traveling from Earth to Mars will happen on the night side of the planet. (You can, of course, get around this by not burning at closest approach, but this massively increases your delta-v requirements and forces you to do a lot of orbital maneuvering to get into the proper orbit -- and if any of that maneuvering requires you to perform a burn on the night side of the planet [which is almost a certainty] you're totally screwed.) (Actually, it gets even worse than that, because I remember that the phase angle for Earth/Mars Hohmann transfers involves beginning your transfer burn on the night side of Earth too.) Your solution at that point is to move the collector off the spacecraft and rely on beamed power/lasers, which is all well and good, but has its own issue in terms of infrastructure requirments and also doubling as an orbital superweapon. Edit: Also, some figures for space nuclear reactors, just for reference. Most proposed/prototyped designs for spaceborne nuclear reactors (be it for propulsion or power) have a mass in the range of 0.5 to 1 metric ton for the core (unshielded). Adding a shadow shield adds another ton or so. 2 metric tons is not at all unreasonable for an engine that can get exhaust velocities of in excess of 8000 m/s and can function as a power plant in low-power mode. And doesn't go out whenever you get occluded by a planet.
  8. GreenWolf

    Everyday Space Drives

    But it comes with its own drawbacks, such as thrust drop-off the further you get from the Sun, planetary occlusion (that's going to be a really big one if you intend to use it for planet-to-planet transfers), and a huge mirror/heat exchange apparatus that probably ends up massing more than a decently designed nuke + shadow shield.
  9. GreenWolf

    Everyday Space Drives

    Throwing my two cents in, since I've been doing a lot of number crunching and general thinking on this subject lately for a book. I doubt we'll ever see manned interplanetary spacecraft with a crew of less than half-dozen (maybe a little bit lower if you make some generous assumptions about AI and robotics), and that would be on non-bulk cargo carriers. (Caveat that I'm assuming something like Rick Robinson's Mission Control Model, where the crew are mostly there to oversee the automated subsystems of the ship and maybe make repairs.) Personal spacecraft will be rare or non-existent, especially for passengers/leisure/tourism, because transfer windows will constrain when you can use it (and thus make it easier and cheaper to just take a dedicated liner). Spacecraft will be more like trains than cars, and most of them will be owned by larger collective entities (like corporations and cooperatives) rather than individuals. Part of that is cost of owning and operating a deep space vehicle, part of it is the way in which spacecraft would be used, and part of it is regulatory, to a degree. As for the design of such a spacecraft, that depends on what you want. If you're moving ice or metals, time isn't really a concern, so you'll be angling to maximize payload and specific impulse. For ice, you'll get popsicle-pushers -- basically a nuclear reactor on a stick, shoved into a chunk of ice carved off a comet, using some of the comet as remass. Your propellant is "dirty" (in that it's going to be a mixture of whatever the comet is made out of -- likely water, ammonia, and some carbon dioxide), so your specific impulse isn't great for an NTR, but you've got plenty of material available, and you can afford to take low-energy, long-transit transfers. For metals/minerals mined out of asteroids, you'll probably be using nuclear electric instead of nuclear thermal -- using a nuclear reactor to run an ion thruster or mass driver. Again, travel time isn't a concern, and since you don't have a readily available source of reaction mass, you'll be optimizing for efficiency. But that's fine, metals don't care. For things carrying people -- be it passenger liners doing an Earth/Mars run, or non-bulk cargo carriers with a minimal crew -- you'll be wanting to strike a balance between travel time and delta-v. NTRs hit this balance pretty well, and depending on your propellant and core design, you can get exhaust velocities of as much as 8000 m/s. A lot of people like hydrogen, because of its low mass and ready availability, although I personally favor ammonia, at least on an Earth/Mars cycler. Your exhaust velocity isn't as good (only in the range of 5000 m/s), but your fuel is a lot denser and easier to handle (providing some impressive savings on tankage and structural mass), and the increased thrust lets you be more aggressive with your maneuvering. And ammonia, while less abundant than water (and thus, hydrogen), is still pretty easy to get. The basic design of one of these spaceships would then look like a very long dumbbell, with the drive unit (with the reactor and a cluster of propellant tanks) at one end of a long structural truss, and the hab module at the other. Cargo and additional propellant tanks can be attached along the length of the truss. While not exactly modular, the drive section could be detached for servicing, or jettisoned in an emergency (although the hab module would then be left with limited or no independent maneuvering).
  10. GreenWolf

    Circling Minmus in a Cricket -- "We found Santa."

    Indeed. I did my best to design the Cricket with long-range over varied terrain in mind, keeping in mind the problems that some previous Elcanoists have had, and I would say that I've largely succeeded in that regard. The design itself is robust and capable enough, but there are a couple things I hadn't accounted for. The first, of course, is the rate at which Dang It failures would occur (normally I don't have a vessel in-focus and actively doing things for this long), so I underpacked on spare parts. Then, of course, there's the issue of terrain tears (which, fortunately, I haven't seen any more of since the first disaster). I hadn't accounted for the fact that at 50 m/s, slowing down in time for a tear would require me to spot it 3+ kilometers out. But probably the biggest thing is just time and distance. I picked Minmus because it's small, but in 6.4x scale, the circumference of Minmus is just over 2400 km (making it larger than stock Duna). And the route I'm taking is not the most direct path, so that probably adds another 100 to 200 km to the whole thing. As with any Elcano, what it ultimately comes down to is an endurance test. So in a way, I'm glad that I have to send over a resupply mission, because it helps break up some of the monotony of driving. It's also why I'm going to start adding some additional objectives to the mission, just so that I have things to do beyond tabbing in to make sure it hasn't gone airborne.
  11. Version 0.2.0 (Leonov) has been released. Changes in this version: Increased science cost of hiring instructors to 330 Added a cap to the funds cost of hiring instructors Added group basic training contracts Reorganized the contract groups for basic training contracts Fixed issue where the MoonStation parameters were checking for a Base vessel type Fixed issue where the MoonStation and MoonBase durations were reversed from what they should be Culled trailing full stops from the ends of contract requirement descriptions Link to latest release on Github. The next release that I'm targeting will be 0.2.1, which should include compatibility for RSS, GPP, and other planet packs. Current known issues in 0.2.0: Science cost is still only applied on contract completion instead of acceptance. (Can't fix on my end, would require @nightingale to add an advanceScience hook into CC.) Kerbal names in group contracts are enclosed in square brackets and aren't space separated. Should be fixed in 0.2.1 Group training contracts award 4 XP for training from level 0 to level 1, instead of the 2 that they're supposed to. Unsure what's causing this, might be a weird stock interaction (possibly adding 2 XP on top of the 2 XP for orbiting Kerbin? but it also happens when I use a planet-side base to train them). The correct amount of XP is awarded for all other level advances If you find any other bugs or general weirdness, let me know and I'll see what I can do about it.
  12. GreenWolf

    Circling Minmus in a Cricket -- "We found Santa."

    THE JOURNEY (CONTINUED) Part 5 -- E4 to E5 (Full album link.) After spending the night camped out next to the monolith (which mission control insisted was completely harmless), our would-be circumnavigators awoke just in time to watch Kerbin, the Mun, and Kerbol rise in short succession. Before setting off again, Virburry took a moment to place a flag marking the location of the monolith and documenting their discovery of it. Then, with the morning shadows once again at a suitably photogenic angle, they headed north, towards the next waypoint, and the north pole beyond it. The goal was to reach the pole before the sun set again. However, before they were even out of sight of the monolith, one of the tires on the Cricket burnt out. Virburry: "Ugh, seriously? A motor burnout already? We'll never reach the pole at this rate." Patzor: "We're not even up to speed yet, it shouldn't take too long to stop and fix." Virburry: "Nah, I've got a better idea." {Virburry sets the rover controls to auto and starts to get out of her seat.} Patzor: "Whoa, hey, what are you doing? We're still moving!" Virburry: "Don't worry, I'm just gonna do a quick hot-fix." Patzor: "That's not what people mean by hot-fixing!" Virburry: "No, it's what I mean. Be right back." After that bit of excitement, the rest of the trip to waypoint E5 passes quickly and relatively quietly, although Virburry does perform another Burry Brake to slow down when they reach the waypoint, much to Patzor's consternation. Part 6 -- E5 to E6 (The North Pole) (Full album link.) For this part of the trip, I deviated slightly from the direct route (which would have taken me through a rather steep valley that I didn't much like the look of), instead aiming for an intermediary waypoint designated E5.5 (which would take us along the top of a relatively level plateau). Once we reached E5.5, we turned due north and took off on a straight path to the pole. This leg of the trip would be the longest one so far (almost 100 kilometers longer than the trip from E3 to E4), so I didn't want to have to repeat it. Quicksaves were made every 50 to 75 kilometers, and I tabbed back into the game regularly to check the progress. About 50 kilometers into the trip, we had a reaction wheel failure that necessitated a stop (it was too far back for Virburry to reach from the lander can ladder, and trying to walk along the frame at 50 m/s would just ragdoll her). Being very careful not to leave the cover of the shadow shield, Virburry repaired the reaction wheel, using kerbal space magic to fix it despite the solid structural plate between her and the wheel. Then 20 kilometers after that, we had another motor burnout, which Virburry repaired with another hot-fix. At this point, I started to get concerned about the number of spare parts I had left (8), and the rate at which we were going through them (way too high). So Virburry radioed back to Minmus Base to see if a supply drop could be arranged when they reached the north pole. Virburry: "Elcano Expedition to Minmus Base. Anybody home over there?" Valentina: "We're reading you Elcano Expedition. What do you need?" Virburry: "Well this is a bit embarrassing, but we seem to be running a bit low on spare parts, which, as you're aware, we require to perform repairs in the unlikely event that we experience a mechanical failure. Wait, did I say unlikely? I meant extremely likely." Valentina: "Is there something wrong with the Cricket?" Virburry: "Not per se. Just normal wear and tear, writ large. Nothing I can't handle. As long as we don't run out of spares." Valentina: "Understood. You want me to send the Mango over with a resupply?" Virburry: "Has Obgas fixed that engine yet?" Valentina: "Supposedly." Virburry: "Then I would love for you to send it up to the north pole in a couple hours, which we should be reaching shortly." Valentina: "Copy that. Let us know when you get there." Virburry: "Will do. Elcano out." We continued driving north, the sun moving further south as our latitude increased. Pretty soon it was almost directly south of us, and starting to set again. But we were really close to the pole now, and it wasn't much longer before we arrived, sun on the horizon but still in the sky. There was still enough light left to take a few publicity photos, so our cosmonauts hastily planted a flag and posed heroically. Up next: Resupplying and heading south.
  13. GreenWolf

    What are the options for science sinks?

    And I went ahead and made the mod. Well, the first release, anyways. It's not yet feature complete, but the development thread is here.
  14. Inspired by this thread, I spent the afternoon hammering away at Contract Configurator to create an initial release of a basic contract pack that allows you to use science to train kerbals. Features of this release: Kerbals are trained at a rate of 1 XP for every 5 science and 1000 funds Training requires a higher level kerbal of the same profession to act as an instructor Training must take place on a station or base in the Kerbin system The training station must be equipped with a Science Lab Training occurs faster in orbit of Kerbin, even faster in orbit of the Mun or Minmus, and faster while landed on the Mun or Minmus Training requires a level 3 astronaut complex and a level 2 research and development facility There are two training options at the moment: Individual Basic Training, and Intensive Training Individual Basic Training allows you to train a single kerbal of any profession to advance one level Intensive Training allows you to train a single kerbal of any profession from their current level to level 5. This costs additional science and funds, but takes somewhat less time. If you don't have any high level kerbals for a specific profession, and if you meet a certain prestige requirement, you'll be offered the option of immediately hiring a level 5 instructor for that profession, at a high science and funds cost. Future releases will include: Group Basic Training, to allow you to train multiple kerbals at once (although no group intensive training, for balance reasons) Training time bonuses for having profession specific parts on your training station A much better looking agency flag (hopefully) Configurable rates for science and funds costs Do note that because of the way Contract Configurator works, the science cost is only applied after you complete the training, not before. I'm sure some unscrupulous individual could find a way to exploit this, but that's not really my concern. Edit: Oh, and while it's hopefully obvious, yes, this does require Contract Configurator. I'm running the latest version (1.23.2), so it will definitely work on that. Your delta-v may vary on older versions. Edit 2: Oh, also, please don't submit this to CKAN at the moment. I adore CKAN, I use it extensively myself, but this is still in a very early stage where updating between releases will probably break things a bit, and I don't feel comfortable putting it onto CKAN until it's feature complete. Once it is, I'll do the netKAN PR myself. And here's the download link. And the Github repo. License This mod is released under the Mozilla Public License 2.0. The full text of the license can be found in the Github repo.
  15. GreenWolf

    What are the options for science sinks?

    @DrLicor In my experience in my most recent career game, the timers on Contract Configurator contracts do continue to run in the background if you switch focus, so hopefully that shouldn't be an issue. The benefit of making it a standalone contract pack is that it's a lite-weight, standalone download with just CC as a dependency.