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DerekL1963

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Everything posted by DerekL1963

  1. It's different for different setups, but always the same for the same setup. (And it can be measured with the right equipment... I've done it myself.)
  2. Update 10/16/16 Didn't play much over the weekend because of storms... Launched the third and fourth drive units, refueled them at ORF-2 and docked them to the mothership. Except for the T/TV carrying the crew, the vehicle is now complete. Since OPD-2 is now empty, It was de-orbited. Just for amusement, I rode it down into the atmosphere... At this point I was getting an awful headache and packed it in for evening. Next up, the tedious process of fueling the beast.
  3. Set occlusion to 1.0 or higher when you start the save.
  4. The Senate Launch System does have a mission - funneling pork to campaign contributors and keeping jobs in a key Congressional district in a battleground state. Or, in other words, don't forget that even though they enthusiastically cheerlead it for political reasons - SLS is emphatically not a NASA program.
  5. You shouldn't need relay sats unless a few days interruptions when Kerbol is in the way bothers you.
  6. Somehow I turned off the summary... how to turn back on?
  7. Nobody is saying that they are hiding a secret dealbreaker - only that folks shouldn't treat the process as a 'done deal'. The details so often airily handwaved away (in the rare instance they're mentioned at all) hide considerable potential practical complications.
  8. More cargo cult nonsense and handwaving. Boeing, etc... (the guys who have to put up the really big bucks) perform intensive market analysis before even starting on the design, and with rare exceptions have at least a few entries in the order books before they start producing hardware. The first is possibly true for SpaceX (though I don't find it likely), the second we don't know yet but again seems very unlikely.
  9. Theoretically, it's very easy. Practical though... The devil lies in all the details hidden behind the smoke and mirrors of such a high level handwavy view. Where does the power come from? Where does the water come from? Etc... etc...
  10. True, but missing the point - the design and construction costs still have to be paid. And it doesn't matter how many flights those costs can be amortized across, because those costs have to be paid in cash, up front, before it flies even once. Seriously, if you're going to talk bean counter, learn what the terms mean and how things actually work rather than just indulging in cargo cultist mumbo jumbo.
  11. Slow news day mostly I suspect.
  12. Took the evening off from working on my Jool 5 run. Built a 1.2 install (J5 is in 1.1.3) and farted around in career mode, which I haven't tried in over a year. Yep, still loathe career mode.
  13. When I was in the Navy, we called the escape systems on submarines "mommy systems" as in "sure mommy, we can get out if something happens". Among ourselves, we didn't put much stock in them.
  14. LARPing on a truly grand scale... and about as meaningful.
  15. The word from reliable sources is that though the poster had access to the transcript and reason to believe it could be released, it was not actually formally cleared for release. That being said, that's the second unconfirmed "official" explanation I've heard in the last few days. The other was Gwynne Shotwell explaining that the problem was "was harmonic vibration during helium loading". Very odd.
  16. If you have additional ground stations on, you don't to be kerbostationary... Two birds about 1000k up and 180 degrees apart will give you virtually 100% coverage. Even without additional ground stations, you don't need kerbostationary - the birds just need to be in an equilateral triangle and in sight of each other.
  17. Once again, reporting on last nights work because it was so late when I got done... The assembly of my Jool-5 vessel continues with the delivery of my Laythe lander and the first two of four massive drive units. Details in this post to my mission log. As always, questions or comments are welcome.
  18. Update 10/13/2016 The first task last night was getting the Laythe lander in place... after my experience with the Quad lander, I went into the VAB, drained the fuel, and strutted it. Though it still wobbled, it was tolerable. Docking was nerve wracking though - not only did the lander have to clear the docking compartment, the nose cones had to clear the fuel tank. Almost half the fuel in the OFD has been expended just ferrying various components from LKO up to the assembly orbit... But all the ferrying is over, the remaining components all self-deliver. Next up are the four drive modules... And I had an idea that was almost too clever. The drive modules are launched only partially fueled to save weight - what if I could refuel them on the way up? That would save a lot of trips with the tanker later. So the next launch is of a 'stretched' version of the OFD orbiting at 1500k rather than 300k. This means I'll spend less fuel hauling fuel from the OFD up the mothership at 3000k. Figuring out how to get the drives into orbit was "fun" because there's no place on the base to attach anything, and I couldn't do a 'normal' asparagus because of the cooling system. In this design all six boosters are firing at launch, with the four 'corner' boosters feeding into the two 'side' boosters. At launch, only the nose tank (holding 2500 units) is fueled to keep weight down and to control CG so it won't flip head over heels. It reaches orbit with only a hundred or so m/s of DV left in the 'side' boosters. Originally the LV-N's fired during ascent, but once I figured out that they weren't actually needed I decided it was better to save their fuel for use on orbit. A beauty shot of the second drive unit ascending with the Mun and Minmus visible. After launch, the nose fuel is transferred to the aft tank, the drive unit docks to the OFD and fills the two aft tanks. (Only the two aft tanks to keep the t/w ratio in a range I am comfortable with. This is mostly to keep the length of the velocity matching burn during rendezvous down.) Parking the first drive unit was fun because of it's size and weight... And attaching the second added 'clearance' to the 'size and weight' mixture, just upping the fun level. I hate docking, and heaven alone knows why I designed a mission architecture that requires so many. In the end, the drive modules arrive with 9400 unit of fuel instead of 2000 - saving me four tanker trips later on. And the four modules will completely drain the OFD... efficient! As always, questions or comments are welcome!
  19. Last night's work, because it was too late to write it all up... It's too much to post here, so all the details of starting to assemble my Jool 5 ship can be found in this post to my mission log. Meanwhile, let's play "spot the design mistake". The answer is in the post.
  20. 10/12/2016 And so, assembly of the Jool 5 begins... The first launch is of the massive tank farm that will refuel the OTV (Orbital Transfer Vehicle) and later the Jool 5 itself. Then the OTV is launched and docks with the Orbiting Fuel Depot 300 kilometers above Kerbin. This will be the OTV's perch in between missions. Next, the mothership core (the fuel tanks and docking hub) bids farewell to Kerbin as it takes it's first steps on it's journey to Jool. Even though it's only loaded with oxidizer (to save weight), it's still a very heavy load. Though it takes over 80% of the OTV's fuel, the core is safely delivered to the 3000 kilometer assembly orbit. (It's assembled so high so that the lengthy departure burn is only a small fraction of the orbital period.) But when I separate the OTV from the core by jettisoning the core's docking assembly... I find a mistake. Can you spot it? Yep - somehow I managed to put the decouple on upside down. Not enough weight to a cause a performance problem, but still very annoying. My first attempt at docking the Quad Lander was an abysmal failure, because it wobbled all over the place... I haven't seen a ship wobble like that since back before I started using KJR back in .22! Eventually I had to undock the OTV and return it the fuel depot and de-orbit the lander. Unlike the mothership, the lander was launched fully fueled since the weight was well within the capability of the booster and tug. Going back to the VAB and looking at my design I theorized three possible causes: a) the weight of the fuel in the lander (specifically in the radial tanks), b) that I had failed to strut the connection between the docking assembly and the lander, and c) carrying the radial tanks so far forward (by docking to the base of the lander). Fixing "C" meant completely redesigning the lander and/or the docking sequence... "A" and "B" could be fixed far easier, and tested in a single flight, so I went with that option - defueling the lander (leaving only the oxidizer), and strutting the lander to the decoupler and the decoupler to the docking port. The second flight was much more successful, it still wobbled but it was manageable. Of the struts shown below, all but the ones connecting the lander to it's cruise/crasher stage are new. I was just a bit nervous during this portion of the docking... But in the end, it was successful *and* I got the decoupler the right way 'round this time. Six more assembly flights to go, but it was getting late so I called it a night.
  21. o.0 You seriously can't google "spot price of Iridium"? Let me google that for you o.0 Did you read the part where my thought experiment was for ore with 50,000 times the concentration known to exist in space? Which means you need a heat shield. And protection for the drogues. And RCS for establishing initial orientation. And some form of de-orbit system. And... all the other stuff you simply handwave away. Respectfully, it's strongly supported and well deserved criticism - basic mistakes like the one with ore concentration cited just above amply demonstrate why.
  22. Yes, the costs of fetching unrefined resources down from LEO are very high compared to the value of the material. At current prices, iridium fetches $650 a troy ounce, $20k per kilogram. If the asteroid is 5% iridium/metric ton (50,000 times higher than the the actual average of .5ppm in meteorites) - that's $100k per 1 ton chunk you bring back. You probably can't even fuel the booster for that, let alone the balance of your operational costs (even at your handwaved re-use rate). Seriously, the numbers absolutely do not add up when you start running them. So to make it work, you need either something that's freakishly expensive and in demand (and which will remain so even when you start selling*), or a freakish drop in the cost of the energy required to fetch the raw ore. * And it absolutely has to retain those prices when you start selling - because your whole scheme relies on flights by the gross lot to cover your initial capital outlay.
  23. I'd rather gouge my eyes out with a rusty cubic octagonal.
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