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    Bottle Rocketeer

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  1. My suggestions for building space stations. 1) Use Senior Docking ports to join station modules, much less bendy 2) Make your modules of a standard mass ( I prefer 8000 kg), this way you can flat pack a station onto a interplanetary booster without too much work of load balancing (or overpopulation of reaction wheels), send a station anywhere, and build it there. 3) Have a probe core near the center of mass of a station, give it the stations reaction wheels, and control station from there. Cuts down on the kraken attacks. 4) if you use mods, Nertea's Near future construction has nice square cross section struts and docking ports that eliminate alignment issues (once you get them docked together). It's surprising how noticeable a 1 degree misalignment is when the component has solar cells sticking off of them. The square cross section trusses also have tanks that can be inserted inside that help with part count if you are building big.
  2. Where your "control from here" is makes a huge difference on the long term stability of a station. My Rapid unplanned disassemblies occur when the "control from here" is located from a component far from the center of mass of the station, SAS is on, and there are reaction wheels on the station. Same applies for large vessels assembled in orbit My fix from a design standpoint. Have a probe core near to the center of mass of the final station or ship, and set it to "control from here" Auto-strut Reaction wheels to "heaviest part", or "root part", depending on which gets them closer to the "control from here" probe core. this will help ensure the reaction wheels work together on the station, and limit how much the cause docking port joints to flex. Limit the number of reaction wheels, and where possible, keep them close to the center of mass probe core. The greatest potential danger for a disassembly occurs when a component with a reaction wheel docks with the station. Have the reaction wheel on that vessel auto-strutted to heaviest or root part has been generally successful for me in preventing the station from detonating on a docking event. Also, use F5 a lot.
  3. In my practical experience (I go to Moho a lot, its a fun place to go), there is a minimum TWR needed at each stage of the voyage to do it for the minimum possible delta-v for Phase 1 ejection, which is around 2200 m/s of delta -v, if the launch is timed right, a TWR of around .4 to.5 is around the minimum needed to get an accurate ejection to Moho. going much less makes the voyage there much more expensive in delta-v, by hundred of m/s in correction burns. for phase 2, this can be done at .1 TWR, though .2 TWR is more efficient. Ion engines shine here, as you only need a quarter of the solar cell mass per Ion engine, therefore it is easy to build the 2000-2500 m/s delta v stage to capture. However, you will more than likely need to capture in a retrograde orbit (not a big deal given Moho's relatively slow rotation Phase 3, landing, you need at least a TWR of .55 to do it easily, lending itself to a stage with around 1200 m/s delta v for just a landing, 2500 for return to orbit as well, with a small vacuum optimized LF O engine. Ions work for return and Kerbin Capture, but you'll need about 4x the mass of solar sells, or a sizable mass budget of batteries for the kerbin capture. Breaking this out: A 1.25 or 2.5m vacuum LF O engine for kerbin ejection. A Ion stage for moho capture, and small LF O stage for Moho landing. Round trip requires a sizeable Ion stage, and docking in Moho orbit. My unmanned surface probes to Moho are launch able with 1.25m parts and asparagus staging, or more simple 2.5 meter rockets.
  4. I name my manned interplanetary ships after British or American Warships, Using names such as Endeavour, Enterprise, Essex, Invincible, ect. Everything else is named after what they do, (Jool heavy probe, Moho ion probe, ect)
  5. The answer is: It depends on what you are trying to accomplish. If you are looking to build a station, higher orbits (within reason) have added value for greater ease of plotting maneuvers to get ships/components. its hard to catch up with a station ahead of you in orbit if the station is at 75km. For relatively high TWR interplanetary missions (talking around 0.5 TWR) with thin Delta V margins, the lowest possible parking orbit is desired, to make the most of Oberth effect. For relatively low TWR interplanetary missions with ample delta-v, higher orbits allow longer burns to be made accurately (or without causing pe to dip into atmosphere during burn). If the final stage of your launch vehicle is very low TWR, higher orbits are easier to obtain, as there is more time before the vessel re-enters the atmosphere to add the required delta-v to obtain orbit. I had a Whiplash/ Dawn powered SSTO that I couldn't get into orbit with a apoapsis below 100km, but it had all the delta V in the world to get anywhere. Bottom line, there isn't one answer to the question, it depends on the entering argument. Personally, I like 90km as my standard parking orbit. easy to get to, Oberth is pretty good there, easy to set up Rendezvous there even if you botch the timing of the launch, it is tolerant to relatively low TWR interplanetary burns
  6. Not easily without mods. 2 mods that may help. 1) Navyfish's Docking Port Alignment indicator (DPAI). in the alignment indicator, there is a readout of the relative rotation between the 2 docking ports. using this you can get relative rotation within a few tenths of a degree of desired orientation. 2) Nertea's Near future construction: Has a docking port that will only dock if they are precisely lined up in relative rotation (at 0, 90 180 and 270 degree relative rotation). This one is important if you want to radially dock something to a spacecraft that will provide thrust axially. The few tenths of a degree accuracy of the DPAI not enough to keep the craft controllable with radially docked engines. Without Mods, there is the old dual docking port method, where you dock to something else using 2 docking ports. This one has always been finicky because to successfully dock both ports you have to be exactly lined up in pitch roll and yaw axis, else only one docking port would successfully dock.
  7. I have a question on how we define payload? Is this weight of craft to orbit, or weight of just the things to complete the mission? do we factor recovery cost into this? I have a SSTO space plane that costs 32k funds, but if recovered on the runway only expends around 800 funds in fuel (plus a few hundred funds on the occasion I derp the landing and remove a wing). The functional payload is only 3 kerbals, but I get the whole aircraft to orbit, which weighs around 5 tonnes when in orbit. So this could be considered tremendously efficient working the numbers right (800 funds for a 5 ton spacecraft to orbit, equating to 160 funds per ton), or not so efficient (32k fund spacecraft to get 3 80kg kerbals to orbit, for 200k funds per ton)
  8. My recommendation for you is to open up the Atmo readouts for KER. This gives you a lot of useful information about optimizing your rockets. The most efficient rockets I have come up with are Solid Rocket stage, Atmospheric rated Liquid fuel stage, then Vacuum rated liquid fuel stage, with the SRM and 1st liquid fuel stage firing at launch. The different stages should be sized as such. The 1st liquid fuel stage should have enough fuel, when combined with SRM stage for about 3000 m/s delta V in vacuum, with a rocket sized to provide 1.3-1.4 TWR at 5km altitude after the SRM have burned out. this frequently involves turning down the thrust on the rocket tweakables. the SRM stage should be sized to get launch TWR at 1.4-1.5 at the surface. This involves tweaking both the main liquid fuel engine and the SRM engine thrust, and where possible having the liquid fuel stage set as low as possible to get the 1.5 TWR at surface, and the 1.3 TWR at 5km once the SRM have burned out. The final stage should be sized for an approximate 0.3-0.5 TWR, with sufficient delta-V to get to your ultimate destination plus the around 400 m/s needed to pay the 3400 m/s delta V bill needed to get to orbit. The more of the 3400 m/s to orbit you put on the launch stage, the more towards 0.5 your vacuum TWR needs to be at stage initiation. With this design, I can get 7 kerbals (payload around 8t with cabins and needed re-entry gear) to orbit for 30k (without recovery), using a gravity turn, and throttling my engine to keep time to apoapsis around 50 seconds until desired Ap altitude is reached. my cargo launches are similarly efficient.
  9. Drop the intercoolers and put a shock cones instead. The flat surface of the intercooler is really draggy. this may also be impacting your controllability.
  10. I think it is important to note, Lift in KSP is a function of lifting surface area and angle of attack. A lifting surface with 0 AOA to direction of travel generates no lift. What the deploy flaps does allows for more lift generation at a shallower angle of attack for the main wing. What I have found is that well placed flaps actually help get aircraft off the runway by generating lift when the main wings themselves may have only a very small AoA, especially for aircraft intolerant of significant rotation on the runway or approaches at significant angles of attack.
  11. I tend to put high power relays in extremely elliptic polar orbits of Eve and Duna. These 2 relays, along with Kerbin, will result in a very high percentage of time in contact for nearly every body, with slightly less effectiveness for Jool and Eeloo, but a lower power relay attached to a normal Science probe can assist in closing these gaps.
  12. To make career more challenging: Turn Technology unlock costs on: Require both science and funds to gain access to new parts. Frequently drives strategies to turn science into funds, and delays full tech tree unlock until you visit bodies outside Kerbin and its moons. Turn off the extra ground stations. Drives an absolute requirement to build out a comsat network, especially if you are trying to get unmanned missions into space. it also limits the approach vectors you can enter other planets at, so you have comms contact when you make your insertion burn. Drive need to place high powered relays at strategic locations in the Kerbol system, or use pilots using relays to control things in system Require comms network contact to control probe cores: the above reason, and it makes your first comms satellite more challenging to launch. Turn re-entry blackout on: added difficulty returning unmanned probes and reusable launchers Increase re-entry heat: works to prevent Mk-1 spaceplanes, which can be ridiculously efficient in completing Kerbal rescue missions in LKO. a well designed Mk1 space plane can recover a kerbal from LKO for under 2000 funds if you land back on the runway, making these stupidly profitable (70k made for 2k in expense, and don't have to hire the Kerbal). Drives the need to use Mk2 or Mk3 space plane parts if you are looking to go to orbit off the runway, or drives design compromises with Mk1 space planes to use them for re-entry.
  13. I'll one up you. I'm and American living with Greece (temporarily), with children going to a local Greek school, but who will, in a few years, be in a school in the U.S.A. We use imperial units at home, when everything else is in metric. every day from my wife "what's 425 in Celsius", "how many grams in an ounce" and "how many milliliters in 2 cups" because all our recipes are in cups, oz. and degrees Fahrenheit, and our oven, scales and ingredients are in metric. Being an engineer, I am fluent in all the measurement systems, but it is hard explaining metric in relative terms. Imperial is definitely easier in that regard. And even more, I'm a mariner by profession, so I think of distances in nautical miles (6076 ft, or 1 minute of latitude (1/21600 of the earths circumference, measured through the poles). That unit is by far the most logical measurement of distance for me, and I can directly relate it to the coordinate system we use for charting. The most efficient way of capturing the energy from splitting the atom is by using water as the medium of heat exchange, and water in its gaseous form is extremely effective at turning turbines, converting the tremendous thermal energy of the fission of uranium into usable mechanical and electrical energy. I'm both an electrical engineer, and a nuclear engineer. the NERVA is my favorite engine in KSP, because I trained at one of the locations the engine was designed and tested (though long before I trained there)
  14. KAC only works when you remember to set alarms (or have the mod set them for you). +1 Vote for KAC being stock.
  15. All you really need for docking, if you are a fan of mods, is NavyFish's Docking Port alignment indicator. Once you learn the interface, it makes docking so much more efficient, and easily accomplishable with just SAS heading hold. Most of my docking maneuvers are accomplished with about 5m/s of RCS delta v once you finalize the intercept and match velocities with your main engines. For RDVU, the most important thing to remember that adding thrust with your heading offset from your retrograde velocity marker pushes your retrograde velocity vector away from your heading on the nav ball, and if your retrograde velocity is sitting ontop of your anti target marker, and you are relatively close to the target, you should have a close RDVU. How I work this is to set up an initial RDVU with a maneuver node either a half or a full orbit ahead ot the expected intercept. warp to a position about 3 minutes before RDVU, then gradually (and occasionally) retrograde burn, off setting slightly to line up retrograde vector with anti target marker. Keeps your engines pointed in the general direction of target (allowing for emergency stops) and gets you there relatively quickly.
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