egg changed the topic of #principia to: READ THE FAQ: http://goo.gl/gMZF9H; The current version is Гельфонд. We currently target 1.8.1, 1.9.1, and 1.10.1. <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
<discord->
CaptainKeeble. — whats the average amount of dV that would be used to transfer to Venus?
<discord->
CaptainKeeble. — this is what i have and idk if i could somehow get it lower
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CaptainKeeble. — would this work better then KAC since it has compatibility with RSS?
<discord->
Kirk (He/Him). — No
<discord->
Kirk (He/Him). — Even without principia its pretty inaccurate
<discord->
CaptainKeeble. — hmm
<discord->
CaptainKeeble. — alright
<discord->
CaptainKeeble. — and somehow Venus went completely dark
<discord->
CaptainKeeble. — why is my maneuver having a seizure when i make the smallest change
* raptop
feeds mechjeb some levetiracetam
<discord->
Butcher. — Hmm twp is better than kac. But it's not great since it plans for equatorial parking orbits.
<discord->
CaptainKeeble. — i really dont know what im doing wrong with this transfer
<discord->
CaptainKeeble. — i used KAC for my transfer window time, i launched and I still need around 5000 dV to go to Venus
<discord->
Butcher. — I use twp for timing. But I use kos for calculating the actual launch, because getting the lan right makes a big difference to transfer cost.
<discord->
CaptainKeeble. — ok wait i actually got a good transfer
<discord->
Paculino (ŝi/ri/she/they). — What coordinate system do you use to point the rocket?
<discord->
CaptainKeeble. — well its decent
<discord->
CaptainKeeble. — but its better then 5000 dV
<discord->
Paculino (ŝi/ri/she/they). — What (KOS internal) coordinate system do you use to point the rocket? (edited)
<discord->
Butcher. — I'm not sure what you mean by this?
<discord->
Paculino (ŝi/ri/she/they). — Do you use the basic heading, or what?
<discord->
Butcher. — It depends what I'm doing.
<discord->
Paculino (ŝi/ri/she/they). — For the LAN
<discord->
Paculino (ŝi/ri/she/they). — Do you use the basic HEADING, or what? (edited)
<discord->
Butcher. — LAN depends on timing not heading.
<discord->
Paculino (ŝi/ri/she/they). — But for corrections to get it exact
<discord->
Paculino (ŝi/ri/she/they). — Because the launch can't be timed perfectly
<discord->
Butcher. — You time your launch such that when you have inserted into an orbit of the required inclination it will have the desired lan.
<discord->
Paculino (ŝi/ri/she/they). — But it won't be exact
<discord->
Paculino (ŝi/ri/she/they). — You need minor corrections for that
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Butcher. — Oh it doesn't need to be fractions of a degree accurate
<discord->
Paculino (ŝi/ri/she/they). — What's the point of KOS if you don't get it that accurate?
<discord->
Butcher. — To calculate the lan in the first place...
<discord->
CaptainKeeble. — is there a way to make it so when the maneuver is in the past it doesnt remove it from the navball? It ruined my transfer
<discord->
Ashnoom. — You kOS script kiddies are like magicians to me
<discord->
Butcher. — You could use a different mod or even hand calculate the required lan and inclination if you wanted.
<discord->
Butcher. — But I find that tedious so I use kos. It's accurate enough that my transfers are usually pure tangent burns.
<discord->
Butcher. — I steer to correct inclination rather than lan anyway.
<discord->
Butcher. — @CaptainKeeble ideally when it's in the past you have completed it...
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CaptainKeeble. — well 99.99% of the time that never happens
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Butcher. — If you're overrunning the manoeuvre by more than say a second then it's going to be quite inaccurate.
<discord->
Butcher. — Even a second isn't great.
<discord->
CaptainKeeble. — no matter what i do it will always be inaccurate
<discord->
Butcher. — Pack some rcs for corrections.
<discord->
CaptainKeeble. — i already have RCS, but the maneuver goes away when im not even like 90% done with the burn
<discord->
CaptainKeeble. — so its stupidly off
<discord->
Butcher. — How is your planned duration so far off?
<discord->
CaptainKeeble. — ¯\_(ツ)_/¯
<discord->
CaptainKeeble. — i start burning right at T-0 and it still ends when im not even done burning
<discord->
Butcher. — You're planning work the active engines right?
<discord->
CaptainKeeble. — yep
<discord->
Butcher. — You're planning with the active engines right? (edited)
<discord->
Butcher. — You need to light most engines before t=0
<discord->
Butcher. — As you need to account for spool up.
<discord->
CaptainKeeble. — well i do around t-1 or something
<discord->
Butcher. — 0.9 for pressure fed and 2.4s for pumped work for me.
<discord->
Butcher. — It should be pretty much exact then. Do you have inertially fixed set correctly?
<discord->
CaptainKeeble. — no
<discord->
CaptainKeeble. — wait
<discord->
CaptainKeeble. — what?
<discord->
Butcher. — It should be checked if you can't steer (i.e. You're slim stabilised).
<discord->
Butcher. — It should be checked if you can't steer (i.e. You're spin stabilised). (edited)
<discord->
CaptainKeeble. — i have RCS and an engine gimble
<discord->
Butcher. — Then it should be unchecked.
<discord->
CaptainKeeble. — it is
<discord->
Butcher. — I'm not sure why your timing is so far off then.
<discord->
CaptainKeeble. — idk
<discord->
CaptainKeeble. — well i finally got a good Venus transfer
<discord->
CaptainKeeble. — apparently I was leaving Earths SOI a bit too early
<discord->
CaptainKeeble. — like 17 hours too early i guess
<discord->
Ashnoom. — Do you have to rebase the flight plan after doing the first attitude control to point towards the manoeuvre mode?
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Ashnoom. — (if the RCS isn't balanced)
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CaptainKeeble. — I would only do it if it made a massive difference
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<discord->
scimas. — Whether the RCS is balanced or not is irrelevant. Since you made a correction using RCS, the rocket's mass has changed, which means that the duration of the manoeuvre will have a different effect on the rocket. So you should rebase the flight plan.
<discord->
CaptainKeeble. — ugh
<discord->
CaptainKeeble. — make sure to test your orbiters before you fly them
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CaptainKeeble. — cause i went to Venus and I was just spinning out of control
<discord->
CaptainKeeble. — i want to die
<discord->
CaptainKeeble. — welp time to wait until next time
<_whitenotifier-8975>
[Principia] eggrobin labeled pull request #2845: Support for repeated strings in the generator - https://git.io/JL5Q2
<discord->
lpg. — rebasing can never be a _bad_ idea
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<discord->
Ashnoom. — OK. Figured :-).
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Ashnoom. — I assume btw that Principia accounts for TWR changes during the actual burn?
<discord->
Butcher. — It does
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Ashnoom. — I think it was in this channel. Related to 'transfer windows' and that KAC's or TWP's werent all too accurate because they assume an equatorial orbit? Any clue on the mod 'Astrogator'? https://forum.kerbalspaceprogram.com/index.php?/topic/155998-18%E2%80%93111-astrogator-v0102/
<discord->
Butcher. — Not seen it before, but it uses current orbit which is not much user of you're on the ground.
<discord->
Butcher. — TWP can be made more useful in a way by setting the earth orbit altitude to 0, that way it gives you the ejection velocity directly rather than cost to get to it from equatorial orbit.
<_whitenotifier-8975>
[Principia] pleroy closed issue #2838: Add support for repeated strings in the interface - https://git.io/JLQhY
<_whitenotifier-8975>
[Principia] pleroy closed pull request #2845: Support for repeated strings in the generator - https://git.io/JL5Q2
<_whitenotifier-8975>
[Principia] pleroy pushed 6 commits to master [+6/-6/±14] https://git.io/JLdl7
<discord->
Sumguy. — But wait. Does it take into account staging?
<discord->
Butcher. — Does what?
<discord->
Sumguy. — The manœuvre planner
<discord->
Damien (it/that). — No
<discord->
lpg. — > I assume btw that Principia accounts for TWR changes during the actual burn?
<discord->
lpg. — to be precise, it accounts for what it _expects_ to be the TWR changes during the burn, based on the current state of the vessel. if the _actual_ burn occurs after a change in that state (like dropping a stage), that won't be considered
<discord->
egg. — Principia’s model is Циолковский’s, where your rocket is entirely made of propellant and the engine characteristics do not change
<discord->
lpg. — I keep wondering but not trying to find out: what happens if a flight plan asks for _more_ than the entire rocket's worth of propellant? (making the vessel's final mass negative)
<discord->
egg. — I think that’s impossible, the burn is specified by Δv, not time, and when your mass reaches 0 your total Δv is infinite
<discord->
lpg. — ah right
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<_whitenotifier-8975>
[Principia] pleroy opened pull request #2846: Adjust tolerances for macOS - https://git.io/JLd6h
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<discord->
egg. — The granularity is no larger than 2.22⏨-308 kg though 🙃
<discord->
egg. — The granularity is no larger than 4.9⏨-324 kg though 🙃 (edited)
<discord->
DRVeyl. — Possibly. And yay for double.epsilon.
<discord->
egg. — the word epsilon is somewhat annoying because everyone uses a different meaning for it (defining it as the least positive magnitude is quite rare)
<discord->
RurouniDonut. — On the topic of launch windows, doesnt mechjeb need something in orbit in order to get the transfer window?
<discord->
lamont. — no
<discord->
lamont. — use tha LAN of the moon and launch due east and it'll be close enough to the ecliptic
<discord->
RurouniDonut. — And then use the transfer planner?
<discord->
RurouniDonut. — I typically just cheat an old dead satellite to what inclination I will launch into and use the transfer planner from there.
<discord->
Sumguy. — I blow up my dead satellites so my save doesn't bloat too much
<discord->
lamont. — right you're cheating the satellite into orbit, but since MJ has the option for manual LAN now you don't need to do that, just set the LAN and inc. but that means you need to know the LAN of the ecliptic/moon.
<discord->
lamont. — find that value and you don't need the old dead satellite (and we're in #principia so hyperedit is very bad)