raptop changed the topic of #principia to: READ THE FAQ: http://goo.gl/gMZF9H; The current version is Fréchet. We currently target 1.5.1, 1.6.1, and 1.7.x. <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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<discord->
Myshiko. — @SláinteMhaith MechJeb is overrated with Principia.
<discord->
Myshiko. — @Butcher I launch into the plane of whatever the site inclination, but time the launch so that moon arrives at the intersection of moon orbit and launch site plane exactly when my craft arrives there.
<discord->
Myshiko. — Effectively I launch once a month, but that’s ok with RP-1, since Moon rockets rarely build faster then 1 per month anyway.
<discord->
Myshiko. — I could have launched twice per month, but I simply don’t bother (yet)
<discord->
itsRyan. — If you're above the lunar plane, there are two such launch windows per day.
<discord->
itsRyan. — Below it, it's probably easier to just launch into the plane.
<discord->
Myshiko. — Below, yes.
<discord->
lpg. — above, there's 2 opportunities per month for due-east launches. only took me ~5 careers to nail down timing
<discord->
lpg. — (a blurry 2. probably once a day for a couple of days around each window)
<discord->
itsRyan. — I believe I've got the math worked out for two per day due east (at least is seems to be working so far). The plane you're launching into due east makes a full 360 sweep of the lunar plane each day (again if your lat is above lunar inclination). My launch script is here if you want to have a look. Kinda WIP and sloppy but works: https://github.com/ryanc55/KOS-Scripts/blob/master/moonlaunchwind
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<discord->
itsRyan. — Oh, unless you meant *direct* launch to the moon, then yeah, two per month.
<discord->
itsRyan. — Oh, unless you meant *direct* launch to the moon without a parking orbit, then yeah, two per month. (edited)
<discord->
lpg. — I didn't but I should have 🤪
<discord->
itsRyan. — I was thinking of extending the script to do direct launches, but then I'd have to write the control functions to correct for launch profile and gravitational effects. I gave up and just do a once around.
<discord->
Andrew Chen. — has anyone seen this sort of jerky rotation behavior before? this is on principia fubini but i haven't tried without prinicipia yet
<discord->
Falcon. — that is how it should behave i believe
<discord->
Falcon. — but i didnt think it would do that in atmosphere
<discord->
Falcon. — only in vacuum
<discord->
Acer_Saccharum. — nope, it is a glitch
<discord->
Acer_Saccharum. — and it's been talked about for the past two weeks or so here
<discord->
Acer_Saccharum. — It's a problem with PhysX
<discord->
Acer_Saccharum. — and the assumptions @ egg and pleroy made about what PhysX does or doesn't do
<discord->
Andrew Chen. — ^ this is what i suspected but reading the discord history i couldn't pin it to phsyx
<discord->
Falcon. — Does it have anything to do with how Principia behaves in a vacuum? since it partially behaves like that when rotating in space
<discord->
Falcon. — idk, am tired, just threw my 2 cents in
<discord->
Acer_Saccharum. — the jerkiness is a glitch, atmospheric or vacuum
<discord->
Acer_Saccharum. — the jerkiness is a glitch, atmospheric or vacuum
<discord->
Acer_Saccharum. — well it isn't a glitch but it's not supposed to happen (edited)
<discord->
Acer_Saccharum. — apparently PhysX conserves angular momentum by keeping angular velocity constant, but that runs counter to what Principia Frobenius and Fubini try to do, so issues arise
<discord->
lpg. — see principia issue 2519
<discord->
Andrew Chen. — Yep I've read into that already, I just wasn't sure if 2519 was the source of this and similar issues I've been having. I think it may be impacting my aircraft too; any roll input causes yaw angular velocity within half a second that seems like adverse yaw, but is nearly instant and can be very large in magnitude.
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<discord->
lpg. — yeah that sounds like the fubini version
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<discord->
Proton-M blok DM-SL. — i had the same problem
<discord->
Proton-M blok DM-SL. — but in my case, whenever a craft was in a fairing, the rocket shook itself to pieces and crashed the game
<discord->
Proton-M blok DM-SL. — but i switched to frenet and it was all gud
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<discord->
Profiremu23. — I need to practice to Venus flybys
<discord->
Profiremu23. — I need to learn how to do a Venus/Mars flyby
<_whitenotifier-d13c>
[Principia] pleroy labeled pull request #2566: Three new API functions - https://git.io/JfWFL
<discord->
Myshiko. — @itsRyan direct launches to the moon are handy - rocket staging is simpler. Mostly relevant to the users of long burning RD-108
<discord->
Myshiko. — @Profiremu23 TransferPlanner / MechJeb to give an approximate launch date, then early morning / early evening polar launch to get to the parking orbit, then burn-burn-burn, and you have a flyby.
<discord->
Profiremu23. — Hmmm....
<discord->
Profiremu23. — My experience is you need a intersection burn in mid-flight, to correct the flyby altitude
<discord->
Profiremu23. — My experience is i need a intersection burn in mid-flight, to correct the flyby altitude (edited)
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<discord->
Departed. — Why can't I get a 0 relative inclination to the moon? I'm launching from KSC, default 28 inclination parking orbit at 200km and using the Mechjeb Ascent Guidance with timed launched (into the plane of the target)
<discord->
Departed. — Still I'll end up at 10 degree relative inclination
<discord->
egg. — what is the year
<discord->
Departed. — 1961
<discord->
Departed. — July
<discord->
egg. — I think you can’t launch into the plane of the moon from KSC in that year
<discord->
egg. — so either you have to do a dogleg south, which MechJeb is not capable of, or you have to launch further South
<discord->
Departed. — Or a inclination change at the parking orbit?
<discord->
egg. — that will work, technically, but it is extremely expensive
<discord->
egg. — at that point you are better off doing polar launches
<discord->
Profiremu23. — Not worth it
<discord->
egg. — that is what @Butcher recommends
<discord->
Departed. — Ah okay. Thanks. I'll try to manuell launch further south
<discord->
Profiremu23. — Not worth it @Departed (edited)
<_whitenotifier-d13c>
[Principia] pleroy opened pull request #2573: Pass the iterator traits as a template parameter to Forkable and ForkableIterator - https://git.io/Jf039
<discord->
Damien. — @egg, couple of QoL improvements I wanted to run by you:
<discord->
Damien. — Could the orbit analyser give you the elements for bodies vs other bodies (say moon around earth) so you can have accurate numbers for planning trips to bodies with precessing orbits?
<discord->
Damien. — Could the positions of L-points be marked on the map (a simple dot at the centre) when in frames like ECSA and MCEA?
<discord->
Damien. — for the latter, using the flight plan to probe where they are and waiting for the loop using the MK1 eyeball feels backwards. It'd be good to know where your trajectory is in relation to it so you can adjust accordingly
<discord->
egg. — we go back to the eternal issue that the Lagrange points move in ECSA (which I should definitely rename to ECSO but I digress) so a dot would be useless, you would not know when it is wrt the trajectories shown
<discord->
egg. — maybe the trajectory of the Lagrange point could be shown, but that seems messy
<discord->
Damien. — maybe I'm misunderstanding but why would they move?
<discord->
Damien. — I know it's not that simple but you get what I mean
<discord->
egg. — yes, so then that means it is the trajectory of the Lagrange point that you want
<discord->
egg. — it is not a question of *in that case*
<discord->
egg. — if it works for ECSA it has to work for pluto-centred, sun orbit as well, there is no difference from our point of view
<discord->
Damien. — fair enough. just thinking of the most practical way to have a ballpark target to use instead of eyeballing it using the flight plan as a fuzzy probe
<discord->
egg. — there *cannot* be a fixed point representing a Lagrange point, unless we bring in the rotating-pulsating frame
<discord->
egg. — and having the trajectory of what is already a kind of weird « construction line » kind of thing (it’s not like there is an actual body at that location, it really is a property of the two bodies in isolation) is very weird
<discord->
Damien. — ok so I get there can't be a fixed point, can there not be a set of bounds it can be between?
<discord->
egg. — no
<discord->
Damien. — ok leave it at that then
<discord->
egg. — a trajectory is well-defined at least
<discord->
egg. — bounds are not
<discord->
Damien. — in a frame like ECSA I know roughly where the points are, and can make it work but it just feels backwards letting the flight plan find the points, instead of planning to trajectory knowing the point it is at
<discord->
Damien. — but if it's not doable how I'm imaginging it then ok
<discord->
Damien. — but if it's not doable how I'm imagining it then ok (edited)
<discord->
Damien. — in a frame like ECSA I know roughly where the points are, and can make it work but it just feels backwards letting the flight plan find the points, instead of planning the trajectory knowing the point it is at (edited)
<discord->
egg. — here’s the thing though ; the point is just a geometric construct
<discord->
egg. — what you are finding is not the point per se, but the ability to have a reasonably stable trajectory
<discord->
egg. — only the flight plan can tell you that
<discord->
egg. — adding the point would not add a physically real thing ; it would add a visual aid to reaching a particular category of trajectories
<discord->
Damien. — it's a minor shortcut is all, instead of playing the flight plan slider dance and over shooting and correcting etc until you get it right
<discord->
Damien. — yeah it'd be a visual aid, that's all
<discord->
Damien. — not expecting precision
<discord->
Damien. — thoughts on the other thing? the orbit analyser?
<discord->
egg. — yeah we need to support that in some way eventually
<discord->
Damien. — ok cool
<discord->
egg. — in particular because I have plans to show properties related to sun-synchronicity in the analyzer
<discord->
egg. — in particular because I have plans to show properties related to sun-synchronicity in the analyser (edited)
<discord->
Damien. — actually yeah that did come to mind
<discord->
egg. — and that requires knowing the length of the year
<discord->
egg. — which requires analysing the orbit of the Earth around the Sun
<discord->
Damien. — I've been doing sunsync by copying the orbit specs from the wiki article. but I can't do that on a non-RSS solar system easily
<discord->
egg. — (well, perhaps the reverse, the orbit of the Sun around the Earth, i.e., with respect to the equator of the Earth)
<discord->
egg. — yeah and the wikipedia article thing only gives you some discrete orbits
<discord->
egg. — you can probably get more out of the Capderou book
<discord->
Damien. — yeah it's a bit of a closed book re: learning about *how* to do a sunsync orbit
<discord->
Damien. — the wiki I mean
<_whitenotifier-d13c>
[Principia] eggrobin closed issue #2542: API Request: query the history - https://git.io/JfI69
<_whitenotifier-d13c>
[Principia] eggrobin closed pull request #2566: Three new API functions - https://git.io/JfWFL
<_whitenotifier-d13c>
[Principia] eggrobin pushed 6 commits to master [+0/-0/±27] https://git.io/Jf0ZU
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<discord->
Kobymaru. — So what do people do these days to find interplanetary transfers
<discord->
Kobymaru. — I used to use transferwindowplanner which worked surprisingly well even with principia, but I heard it crashes in 1.8.1
<discord->
Damien. — seems fine to me
<discord->
Kobymaru. — are you saying transferwindowplanner works for you?
<discord->
Damien. — I'm running it on 1.8.1 on my JNSQ install but if you give me a sec I can test it on my RSS install but I doubt it'd be any different
<discord->
Damien. — working fine
<discord->
Kobymaru. — dope
<discord->
Kobymaru. — thanks
<discord->
Damien. — np
<discord->
Damien. — I have no comment on the accuracy of it btw because I've not used it in a long time
<discord->
Damien. — something could have changed
<discord->
Damien. — but it runs
<discord->
Butcher. — With principia you're only after a general window anyway I'd think.
<discord->
Damien. — ^
<_whitenotifier-d13c>
[Principia] eggrobin opened pull request #2574: A new approach to conserving angular momentum - https://git.io/Jf08M
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<_whitenotifier-d13c>
[Principia] eggrobin closed pull request #2572: New member functions for EulerSolver - https://git.io/JfRXJ
<_whitenotifier-d13c>
[Principia] eggrobin pushed 3 commits to master [+0/-0/±6] https://git.io/Jf0EE
<_whitenotifier-d13c>
[Principia] eggrobin f6b4412 - New member functions for EulerSolver
<_whitenotifier-d13c>
[Principia] eggrobin a94cd1c - after pleroy’s review
<_whitenotifier-d13c>
[Principia] eggrobin 1d9f60a - Merge pull request #2572 from eggrobin/euler-solver-functions New member functions for EulerSolver
<discord->
Damien. — ok this is very weird. likely not a principia bug, and I've not installed the new version yet, but I've got a satellite in orbit around the mun, and a lander on it sat in darkness. if I timewarp while watching the satellite in orbit, the lander comes off the surface in a circle, enough to recharge its batteries
<discord->
egg. — hmmm
<discord->
egg. — krash?
<discord->
Damien. — no
<discord->
egg. — odd.
<discord->
Damien. — it's on my JNSQ install
<discord->
Damien. — let me see if I can record it
<discord->
egg. — nah, focus on 2519
<discord->
egg. — whatever that is, if it is a Principia thing it would have to be very ancient
<discord->
egg. — that landed sat is not Principia-managed, so it would be something to do with rotating planets
<discord->
egg. — that landed lander is not Principia-managed, so it would be something to do with rotating planets (edited)
<discord->
egg. — let’s deal with one can of worms at a time
<discord->
egg. — 2519 is a large enough one, and an one that actually gets in the way of people
<discord->
Damien. — yeah no probs, I was just finishing off this mission before I restart my game and install the new version
<discord->
egg. — yeah restarting with RSS is always a rather tedious exercise
<discord->
Damien. — my problem is I've set up a new RSS/RP-1 install but not started it yet. I've got an RSS/SMURFF install that I use for testing stuff but haven't noticed any bug effects when I have
<discord->
Damien. — my main install at the moment is stockish
<discord->
egg. — you’re using Fubini ?
<discord->
Damien. — 2561
<discord->
Damien. — one of your test ones I grabbed
<discord->
egg. — huh, odd that you would not notice anything
<discord->
egg. — I guess it has sufficiently many layers of randomly trying to smooth things that unless you know what you are looking for it is a little hidden
<discord->
Damien. — ascents seem normal, and I've done fer descents but what I've done seemed normal
<discord->
Damien. — I think I did notice some heavy spin on a descent once which probably was the bug
<discord->
Damien. — but I've not been trying to reproduce it
<discord->
Damien. — ascents seem normal, and I've done a few descents but what I've done seemed normal (edited)
<discord->
lpg. — I never noticed anything on ascents until I added a roll program
<discord->
egg. — and then only in Fubini and later, right ?
<discord->
egg. — Frobenius was only a matter of reentries