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Found 4 results

  1. Ascent StartTime (MechJebModuleAscentTime.cs) provides interface between mechjeb and plad's flyby finder, or allows you to plan your interplanetary transfer before you leave the ground. To do so you need to: 1. select destination body (other planet) 2. fill Orbit altitude (will be forwarded to Ascent autopilot) in Ascent StarTime window (it's in list of other mechjeb windowses, if addon was installed correctly) 3. generate with initial guess and tune buttons or fill (from PLAD's flyby finder, or other sources such as alexmoon's Launch Window Planner) following values: DepartureDay ArrivalDay which path to use short one or long one, usually preferable one with lower Boost deltaV, but in some cases to get to next gravity assist you would need to be more specific, so there is no auto here by default, but any previously mentioned tune button will auto that. 3. after that you could just Press Choose button to fill most optimal parameter that defines inclination (previously mentioned auto tune will do it for you), it will find parameter that correspond to lowest possible inclination of initial orbit, which HOWEVER do allow both: launch from your launch site (your current position on planet surface) and chosen interplanetary transfer. or if you need more specific orbit you could fill Orb[ital] Par[ameter] of incl[ination] by yourself. 4. after that you could use DrawIntermedOrbit button ( Choose or tune buttons will do that also ) to show orbit in orbits screen (M), more important that Boost from Circular [orbit] field will now show calculated tranfer deltaV, which should up to 0.1m/s correspond those from PLAD's flyby finder, or just (in case other sources of tranfer time) be good enough for you. other fields which can be useful: BoostPrepareDays - how much time (in days) you want spend on orbit of current planet. (you could build boost with several passes, but you would need time) BoostPrepareOrbits - same(additional to days) but in orbital periods of shown orbit (it's not circular!) LaunchOffset - will start early by that number of seconds, allowing vessel get to upper layers of atmosphere, or you will miss selected orbital plane because of planetary atmosphere rotation (with planet itself), best values 90 sec for kerbin and 150 for earth, write here if you find better, spaceplanes could require more. HoursPerDay - just to choose between kerbal/earth day OffsetHours(firstday) - i probably should replace this field with something like offset day, currently should be same as HoursPerDay, and for PLAD's fly by finder both fields should be 24. (at least old for version) Launch countdown - same as in mechjeb's ascent guidance (i.e. how many last seconds will pass with warp 1x) PartialBoostGuidance - parameter for displayed orbit, which allow you to see how orbit will looks like after acceleration by this speed in proper time (beginning of interplanetary transfer), for technical reason can't be 0(i.e. displayed orbit is never circular), but value can be 0.0001 * (Boost from Circular) again Boost from Circular is accounted from exactly circular orbit with selected Orbit altitude 5. press button Launch to circlular orbit (it will update and calc orbit again anyway, so may be needed to check it, if some bugs got there) 6. (optionally) tune values in Ascent Guidance window. 7. press engage autopilot (do the same in both windows, but better do it in "Ascent StartTime", as caller is tracked in MJ) 8. after reaching orbit CreateTranferNode button will be available to create transfer maneuver node (this done mostly with slightly modified mechjeb code, when i did tests precision was 1m/s or better) but you could just do prograde burn manually - you have marked point on orbits map, where you need to do burn (in case marker orbit and your orbit matched closely) (p.s. there was bug that orbit marker is drifting over time, so DrawIntermedOrbit may have to fix that, better to press it before burn, CreateTranferNode also call same code to prevent any error appears, if you could reproduce or know why it's happens i will fix it) 9. and CreateCorrectionNode button would place correction node as soon as possible (after all nodes) this button use 100% mechjeb code (only with fixed arrival time filled from ArrivalDay field) and it's buggy(2 authors of mechjeb why?) while you fly in source planet soi, if you want correction early (than leaving source planet soi) you need to do it manually. I did find cases when launch to inclination choose completely wrong times (on minmus orbit), so i did add same feature to that addon, with completely different code (which is used for primary purpose of addon anyway) i.e. "Launch into plane of target" just doing the same job as button in ascent guidance but without bugs :). take into consideration that current MJ version did not account for initial (start) orbital velocity (due to rotation of planet) when it goes for inclined orbits (so it will end with incorrect inclination), so you need to make correction by yourself in upper layers of atmosphere, you need keep 10 degrees on correct side for 10-20 sec, you don't need even turn of autopilot for that (MJ devs said that bug is fixed in dev build), mine last 5 attempts(while i did test that) result into orbit with relative inclination less than 0.05 degrees from calculated. with life realistic plugins for ksp i would recommend to use fake vessel and warp time (using this addon to step 7) until 1 min before launch(Launch countdown = 60), then abort and recover fake vessel and select proper one, and do proper launch (you would need to select target/planet again, other values should be saved so you could press launch in circlular and engage autopilot). "Launch to circular orbit" button uses latest allowed(by limitation) time for launch (to keep vessel in parking orbit minimum time, because life realistic plugins will spend your resources while you in orbit). "Launch into plane of target" button uses earliest allowed time. Auto tuning DepartureDay and ArrivalDay supported, i.e. you don't need external window planner anymore, unless you want several flyby. InitialGuess: makes them for almost circular orbits (all celestial bodies in original ksp looks good enough) and not much inclined. Tune makes it almost perfect (there are separate buttons for DepartureDay and ArrivalDay and also combined one near InitialGuess: toggle able Tune2 near Dst.Inb.Spd: allows previously mentioned tuning not only for minimum boost speed (transfer dv), but also for minimum entering orbit burn (stopping) at destination. most of feature still working when you in orbit of moon of starting celestial body, i.e. you could tune intermediate orbit for transfer and left moon in proper time with minimal delta-v (including transfer burn) My landing guidance - highly experimental fork of mechjeb version with a lot more tunable parameters done to allow landing with RO engines, now could only be used after deorbit burn done and in way (i think that you have limited ignitions): source: binary installation: just put this dll near MechJeb2.dll (inside GameData/MechJeb2/Plugins folder, and 2 new window ("My Landing Guidance", "Ascent StartTime") will be in mechjeb list) updated for MJ take into account that interface do change in new MJ version so if you want to use faster you need to download sources and rebuild by yourself (you could just compile with any .NET c# compiler (even without VS installing, just add reference for assemblies dlls { mechjeb2 UnityEngine Assembly-CSharp } from ksp forder) ). outdated: temporary merged with GravityTurn source binary (As accessible as submenu from GravityTurn main menu, but actually it controls Gravity Turn ) small fixes in GravityTurn for inclination and max thrust while too low. P.S. it's old GravityTurn recompiled for 1.2, new GravityTurn without AscentStartTime is there
  2. Hello All. I have accepted a sun flyby contract and I'm having a small issue. The game does not allow you to set the sun as a target, therefore, I am not sure how to aim for it. This is my first attempt at leaving Kerbin space before accepting the explore Duna contract. Any tips?
  3. Hi, I have the Duna 3 Flyby contract and I have no idea when to start my trip to Eve. I plan to fly by Eve and Ike before orbiting Duna. This is my 1st interplanetary trip, and I plan on using the Kassandra Spacecraft by @H2O. What angles should I have Kerbin, Eve and Duna? How long should I stay at Duna? Is there an easy way to work this out? Current date is year 3, day 70. Thanks, Update Firstly let me say, many thanks to you guys. The tips you gave me helped me work out that I needed more information! I found the KSP Trajectory Optimization Tool by @Arrowstar to be quite helpful as it has a multi-flyby plotter (had to switch to Earth time though). It has given me lots of information to digest, however I'm not sure how to turn the information that I have into an actual maneuver! The Delta V and Departure/Arrival dates information is particularly helpful, it looks like I can get from Kerbin to Eve for 1377m/s and then do a 515m/s correction burn at Eve, giving me around 1200m/s left in the transfer stage to capture at Duna. Kerbin Departure Date = Year 2, Day 283 06:54:04.673 (55925644.673 sec UT) Eve Arrival Date = Year 2, Day 334 20:28:13.330 (60380893.330 sec UT) Duna Arrival Date = Year 3, Day 23 17:42:52.033 (65036572.033 sec UT) Burn Information to Depart Kerbin --------------------------------------------- Total Delta-V = 1.377 km/s Prograde Delta-V = 538.875 m/s Orbit Normal Delta-V = -1266.975 m/s Radial Delta-V = 0.000 m/s --------------------- Burn True Anomaly = 358.770 deg --------------------------------------------- Burn Information to Depart Eve --------------------------------------------- Total Delta-V = 0.515 km/s Prograde Delta-V = 515.340 m/s Orbit Normal Delta-V = -0.000 m/s Radial Delta-V = 0.000 m/s --------------------- Burn True Anomaly = 0.000 deg --------------------------------------------- The problem I have now is working out when in my 750km parking orbit I need to do the Initial burn. This is the rest of the information it has given me. Hyperbolic Departure & Flyby Orbits Hyperbolic Departure Orbit from Kerbin --------------------------------------------- Semi-major Axis = -3452.976 km Eccentricity = 1.391 Inclination = 30.437 deg Right Ascension of AN = 178.770 deg Argument of Periapse = 180.000 deg --------------------------------------------- Inbound Hyperbolic Flyby Orbit to Eve --------------------------------------------- Semi-major Axis = -4725.402 km Eccentricity = 2.3764 Inclination = 28.615 deg Right Ascension of AN = 97.408 deg Argument of Periapse = 310.331 deg Periapse Radius = 6503.888 km --------------------------------------------- Outbound Hyperbolic Flyby Orbit from Eve --------------------------------------------- Semi-major Axis = -1984.515 km Eccentricity = 4.2773 Inclination = 28.615 deg Right Ascension of AN = 97.408 deg Argument of Periapse = 310.331 deg Periapse Radius = 6503.888 km --------------------------------------------- Inbound Hyperbolic Orbit to Duna --------------------------------------------- Hyperbolic Excess Vel. = 1.607 km/s Sun-Centric Transfer Orbits Phase 1 Transfer Orbit (Kerbin -> Eve) --------------------------------------------- Semi-major Axis = 11546276.670 km Eccentricity = 0.18242 Inclination = 2.426 deg Right Ascension of AN = 27.461 deg Argument of Periapse = 10.692 deg Period = 7199748.9136 sec Departure True Anomaly = 169.308 deg Arrival True Anomaly = 39.623 deg --------------------------------------------- Phase 2 Transfer Orbit (Eve -> Duna) --------------------------------------------- Semi-major Axis = 15394858.102 km Eccentricity = 0.36852 Inclination = 4.649 deg Right Ascension of AN = 54.115 deg Argument of Periapse = 10.917 deg Period = 11084546.9362 sec Departure True Anomaly = 12.788 deg Arrival True Anomaly = 168.350 deg ---------------------------------------------
  4. I want to do the Mariner-10 mission (flyby of Eve and then Moho) from Historical Missions contract pack, but I don't know how to find the best time or orbit for a transfer. I did see the flyby finder for RSS, but I'm not using RSS. I could just orbit Eve and then transfer from there, but I want to do an actual gravity assist trajectory.