egg changed the topic of #principia to: READ THE FAQ: http://goo.gl/gMZF9H; The current version is Germain. We currently target 1.8.1, 1.9.1, 1.10.1, and 1.11.0. <scott_manley> anyone that doubts the wisdom of retrograde bop needs to get the hell out | https://xkcd.com/323/ | <egg> calculating the influence of lamont on Pluto is a bit silly… | <egg> also 4e16 m * 2^-52 is uncomfortably large
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Smoked 939. — you would think someone would make a RO patch for mechjeb
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Sumguy. — ???
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lamont. — you should do that
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[Principia] rnlahaye synchronize pull request #2900: Use system allocator for containers on macOS (bypassing Unity's allocator) - https://git.io/JtpLC
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[Principia] eggrobin labeled pull request #2900: Use system allocator for containers on macOS (bypassing Unity's allocator) - https://git.io/JtpLC
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[Principia] pleroy closed pull request #2900: Use system allocator for containers on macOS (bypassing Unity's allocator) - https://git.io/JtpLC
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[Principia] pleroy pushed 6 commits to master [+10/-2/±8] https://git.io/JqkOj
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[Principia] rnlahaye 4301c8e - Ignore c99 extensions warning in make-based build. There are many intentional uses of the c99 designator initialization syntax in the codebase.
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[Principia] rnlahaye ba326b7 - Fully qualify some std type invocations. This is necessary for the macOS alloc code to compile. The change in error_analysis_test.cpp is necessary because a non-Principia function is called which returns a ::std::vector. I'm not sure why the friend std::pair in discrete_trajectory.cpp needs full qualification.
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[Principia] rnlahaye 10d86c3 - Add MallocAllocator and test.
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[Principia] ... and 3 more commits.
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JoeV. — I am pretty sure that the apex of the left purple track is the L4 point. It definitely equi distant from the barycenter and the moon center : I think the gif is distorted in the X axis.
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Stonesmile. — Is EM barycentric the best reference frame for the burns?
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JoeV. — I am having problems _staying_ in the the region of the L4. I am, I think correctly, applying both tangernt and normal dv. but I enevitably drop out towards the earth
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JoeV. — @Stonesmile I tried previously to do the transfer burn to L4, and then the "circuralization" burn to stay at L4 both in inertial earth centered, but I was having no luck
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Stonesmile. — I haven't actually gone to L4 my self, but I know @Butcher has
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JoeV. — Maybe he can give some pointers. I have seen the vids from Abrin, but I think that since he did those in stock, and the Mun is much smaller than Kerbin, that things are easier there. Go figure
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Butcher. — Iirc I used emb for planning.
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JoeV. — Certainly the L1 and L2 of Kerbin/Mun are _much_ closer to Mun than the L1 and L2 of Earth/Moon are to the moon
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JoeV. — EMB?
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Butcher. — Once you get there you should be able to get into a fairly stable orbit.
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Butcher. — I was able to get around 1200 days at L4 without station keeping
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Butcher. — Earth - Moon barycentric
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JoeV. — Looking at the plot, and assuming that the apex of the purple lobe is the L4, should I try to make my stabilization burn before I get to L4, right on L4, radially outside of L4?
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JoeV. — by plot, I mean the pic I provided
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Butcher. — A little before I think.
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JoeV. — Ok, and yes, I am doing all this in EMB
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Butcher. — I just sort of messed around until our captured.
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JoeV. — I tried earth inertial for the transfer and the burn to get some theta direction velocity to match the moon, but it was not working
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JoeV. — In general, when you get up there from your transfer from LEO, you are going way slow, so you want to get about 800m/s to even stay up there, right?
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lpg. — I'm speaking with little knowledge here, but if the apex is at L4, I'd have expected to need very little in the way of Normal burn to "stop" there
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JoeV. — Yeah, that was what I was expecting as well, and the fact that this is not the case could be very well that I am incorrect about the accuracy of my transfer.
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JoeV. — I had a ruler out and was measuring distances in EMB to make sure I had the triangle right... maybe not
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lpg. — the two purple lobes don't _look_ distorted to me, with respect to each other... but if they're not, they don't seem to be getting close to the moon's "altitude"
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JoeV. — Ah, if I am hitting the L4 like I think, I should see a distortion due to the effect of the moon beginning to make a difference?
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JoeV. — before I even try to burn to stay up?
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lpg. — oh I'm dumb, MJ is showing the Ap. 284Mm seems awfully low, no?
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JoeV. — hmmm, good point, and MJ is always doing the apo relative to Earth's surface, right?
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lpg. — yes
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JoeV. — F-me, good catch, @lpg , sounds like I need to switch back to inertial Earth centered to do a sanity check on my apo when I am doing the first transfer.
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JoeV. — and make sure it is at least close to 380,000km
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Butcher. — You should need around 1km/s to insert iirc, mostly tangent.
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JoeV. — ok, thanks guys. I will give it one more try before packing in the fun for the weekend. Thanks all.
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Butcher. — You are essentially flying out to the apogee and circularising at the altitude of the moon, hence the fairly high fuel cost.
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[Principia] joemos11 commented on issue #2903: Crash doing flightplanning w Principia - https://git.io/JqkdN
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egg. — equidistant from the barycentre and whatever is not what you want (and the barycentre is not shown anyway)
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egg. — what you want is equidistant from the moon and the earth, and specifically, as far from either as they are from each other
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egg. — i.e., the Moon-Earth-L4 triangle is equilateral
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egg. — you are far too close to the earth in that picture