egg changed the topic of #principia to: Logs: https://esper.irclog.whitequark.org/principia | <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|laptop|egg has quit [Remote host closed the connection]
_whitelogger has joined #principia
Raidernick has quit [Read error: Connection reset by peer]
Raidernick has joined #principia
<queqiao-_> ⟨S​abena Sema⟩ where's the windows build actually ... built. I see the azure pipeline but it hasn't had a successful build since september
<queqiao-_> ⟨S​abena Sema⟩ umm actually since october
<queqiao-_> ⟨S​abena Sema⟩ are the actual releases cross built?
<queqiao-_> ⟨P​aculino (ŝi/ri/she/they)⟩ If you are asking for the build that you can install, the google drive link in the readme on the github works
<queqiao-_> ⟨P​aculino (ŝi/ri/she/they)⟩ It is easy to miss
<queqiao-_> ⟨S​abena Sema⟩ no I'm looking for an up-to-date set of pipeline scripts
<queqiao-_> ⟨S​abena Sema⟩ so I can build it myself
<queqiao-_> ⟨S​abena Sema⟩ the released build immediately crashes 1.12.3, so I want to see if I can figure out why
<queqiao-_> ⟨S​abena Sema⟩ oh, it's probably just the version check
<queqiao-_> ⟨S​abena Sema⟩ still, I'm curious
egg|laptop|egg has joined #principia
<queqiao-_> ⟨Z​eusbeer⟩ She grew!
<queqiao-_> ⟨Z​eusbeer⟩ 3x in length but more than 3^3 in volume 🤔
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
<queqiao-_> ⟨s​ichelgaita⟩ The actual Windows release are built on my local machine (which is not ideal from the perspective of reproducible builds). The pipelines stopped working with a compiler upgrade that it to run out of memory because the default agent pool is tiny. To circumvent this we would need to have our own agent pool with moar resources, and that sounded like an unappealing rabbit hole.:rabbit_hole:
<queqiao-_> ⟨s​ichelgaita⟩ The actual Windows release are built on my local machine (which is not ideal from the perspective of reproducible builds). The pipelines stopped working with a compiler upgrade that caused it to run out of memory because the default agent pool is tiny. To circumvent this we would need to have our own agent pool with moar resources, and that sounded like an unappealing rabbit hole.:rabbit_hol
<queqiao-_> ⟨q​p⟩ hello folks, I just posted the issue I am facing at reddit https://www.reddit.com/r/RealSolarSystem/comments/rj5hlk/executing_maneuver_nodes_with_principia/ so cross-posting here as well in case you guys can help give me some tips on what I am doing wrong - let me know if you'd like any more information
<queqiao-_> ⟨q​p⟩ mandatory cat pic cause she's really frustrated I can't do a simple TLI and wonders if we'll ever do more interesting maneuvers if I can't figure this part first 😛
egg|laptop|egg has quit [Remote host closed the connection]
<queqiao-_> ⟨v​on Kerman⟩ "When I manually do the burn and start and stop when principia tells me to"- I'm quite sure that Principia doesn't take into account engine spool up time. That could lead to some error.
<queqiao-_> ⟨v​on Kerman⟩ "When I manually do the burn and start and stop when principia tells me to"- I'm quite sure that Principia doesn't take into account engine spool up time. This can lead to some error. (edited)
<queqiao-_> ⟨e​gg⟩ Open-loop manœuvre execution (following the plan, not looking at what is really happening), which is what both manual execution by timing and MJ Principia manœuvre execution do, is highly dependent on things actually going according to plan. In particular that plan does not account for spool-up, which throws things off.
<queqiao-_> ⟨e​gg⟩ For manual execution, I recommend doing it closed-loop, looking at map view and stopping when things look right in the reference frame relevant to your mission.
<queqiao-_> ⟨e​gg⟩ For manual execution, I recommend doing cutoff timing closed-loop, looking at map view and stopping when things look right in the reference frame relevant to your mission. (edited)
<queqiao-_> ⟨e​gg⟩ for automated execution, I recommend giving @XKdiver a team of astrodynamicists to implement better guidance.
<queqiao-_> ⟨v​on Kerman⟩ The practical problem with this approach is high TWR at the end of the maneuver. I have trouble stopping engines in time manually then the acceleration is 10G 😦
<queqiao-_> ⟨e​gg⟩ yeah; though note that in real life you have some uncertainties like that too, so you always end up having to do a correction after such a high-acceleration burn.
<queqiao-_> ⟨S​tonesmile⟩ Regarding Spool-up time and MJ; RealFuels might be implementing a field that has the "effective spool-up time", that MJ could probalby read and use for this
<queqiao-_> ⟨S​tonesmile⟩ Regarding Spool-up time and MJ; RealFuels might be implementing a field that has the "effective spool-up time", that MJ could probably read and use for this (edited)
<queqiao-_> ⟨e​gg⟩ alternatively, perhaps Principia could somehow fetch and then use the thrust-over-time curve.
<queqiao-_> ⟨e​gg⟩ that would be necessary if we ever want to do something useful about solids.
<queqiao-_> ⟨S​tonesmile⟩ The thrust curve is based on fuel left, not time though. This is because the fuel flow has variation so the time can't be trusted
<queqiao-_> ⟨S​tonesmile⟩ This throws quite a large wrench into that plan I think
<queqiao-_> ⟨e​gg⟩ not necessarily, one can probably be transformed into the other
<queqiao-_> ⟨e​gg⟩ or we could work with one more variable in our integration
<queqiao-_> ⟨e​gg⟩ (re. SRBs, there is an issue to track that :-p https://github.com/mockingbirdnest/Principia/issues/870)
<queqiao-_> ⟨e​gg⟩ (and we still haven’t done anything about it in five years…)
<queqiao-_> ⟨v​on Kerman⟩ Meanwhile I'm trying to solve this issue for myself using a kOS script to execute burns. The script waits until spool-up and then waits for the burn duration shown by Principia. E denotes the active engine.
<queqiao-_> ⟨v​on Kerman⟩ `E:ACTIVATE.
<queqiao-_> ⟨v​on Kerman⟩ WAIT UNTIL E:THRUST>E:POSSIBLETHRUST/5.
<queqiao-_> ⟨v​on Kerman⟩ WAIT BURN_DURATION.`
<queqiao-_> ⟨e​gg⟩ stupid bot
<queqiao-_> ⟨S​tonesmile⟩ Yeah, a kOS script that calculates the spool up gets quite close
<queqiao-_> ⟨e​gg⟩ DM me the script and I can post it if you want :-p
<queqiao-_> ⟨v​on Kerman⟩ E:activate
<queqiao-_> ⟨v​on Kerman⟩ wait until E:THRUST>E:POSSIBLETHRUST/5.
<queqiao-_> ⟨v​on Kerman⟩ wait burn_duration.
<queqiao-_> ⟨v​on Kerman⟩ E:activate.
<queqiao-_> ⟨v​on Kerman⟩ wait until E:THRUST>E:POSSIBLETHRUST/5.
<queqiao-_> ⟨v​on Kerman⟩ wait burn_duration. (edited)
<queqiao-_> ⟨e​gg⟩ you might want to wrap that in \`\`\`
<queqiao-_> ⟨s​teel⟩ What is principia?
<queqiao-_> ⟨v​on Kerman⟩ `E:activate.
<queqiao-_> ⟨v​on Kerman⟩ wait until E:THRUST>E:POSSIBLETHRUST/5.
<queqiao-_> ⟨v​on Kerman⟩ wait burn_duration.` (edited)
<queqiao-_> ⟨S​tonesmile⟩ n-body physics, as described by Newton, instead of the normal gravity in KSP
<queqiao-_> ⟨e​gg⟩ also a book by Isaac Newton
<queqiao-_> ⟨e​gg⟩ For the book see [New87] in the bibliography <https://github.com/mockingbirdnest/Principia/blob/master/documentation/bibliography.pdf>
<queqiao-_> ⟨(​ᴇxᴘᴇʀɪᴍᴇɴᴛᴀʟshells)⟩ which, contrary to what the abbreviation may imply, should not be considered "new" in most senses of the word
<queqiao-_> ⟨e​gg⟩ There is also a [New89] in the bibliography, but that’s not the same New— and not the same eighties either.
<queqiao-_> ⟨q​p⟩ thanks for getting back to me - in regards to spool up - I feel that it's probably under 1sec, could that small difference affect the execution by a really big margin? I typically manually align to the node using rcs then rebase the flight plan about a minute before the maneuver is set to execute, and the fuels are set, the egine ignites right away without any rcs firing for ullage first.
<queqiao-_> ⟨e​gg⟩ > could that small difference affect the execution by a really big margin?
<queqiao-_> ⟨e​gg⟩ depends on the specifics of your burn and the definition of *really big*; but note that the highest acceleration of a constant-thrust burn is at the end of that burn, if you shave off the last second it can change quite a lot.
<queqiao-_> ⟨q​p⟩ thank you, I'll keep trying to fiddle with the manual execution of the burns as MJ seems to be not working and report back if I can't seem to get it to execute properly.. regarding the 'really big margin' in the last couple of tries when I cut off the engines with manual execution, the apoapsis was about 4/5ths of what it should have been, not even reaching close to the moon. I'll try to come back with
<queqiao-_> ⟨e​gg⟩ yeah, the last second matters
<queqiao-_> ⟨e​gg⟩ especially for apoapsis-raising like that, the apoapsis is rising faster and faster for the same increase in speed to start with, and your speed increases faster towards the end of the burn.
<queqiao-_> ⟨e​gg⟩ The answer really is *watch map view*; if you don’t have an intuition of the fact that that last fifth of the way was a second away, you are not doing enough map-view watching.
<queqiao-_> ⟨e​gg⟩ (remember that you can control your rocket while in map view, if you bring up the navball; you should really be commanding cutoff while looking at the map.)
<queqiao-_> ⟨e​gg⟩ The answer really is *watch map view*; if you don’t have an intuition of the fact that that the last fifth of the way was a second away, you are not doing enough map-view watching. (edited)
<queqiao-_> ⟨e​gg⟩ a save file definitely won’t be any use, no two RO installs are the same and we’re not going to start spending time toying with your save or logs unless there is a Principia bug involved. It sounds like there might be an MJ bug in the manœuvre execution? If so, someone should report it.
<queqiao-_> ⟨q​p⟩ yup I was mostly relying on MJ or manually cutting off by looking at the remaining time reported in the flight planner, I'll be doing some practice with the map mode open to see how that goes
<queqiao-_> ⟨e​gg⟩ yeah, open-loop guidance is brittle.
<queqiao-_> ⟨e​gg⟩ OK, back to learning Russian
<queqiao-_> ⟨q​p⟩ ваше здоровье
<queqiao-_> ⟨q​p⟩ so after a few tries while looking at the map screen with manual execution of the burn, and doing a burn that was actually about 8sec longer than what the maneuver planner suggested, seemed to have given me the proper orbit. had to tell MJ to switch from Node to Kill Rotation a sec before the maneuver planner said I should cut off the engine, as the maneuver node gets deleted and the craft just yeets t
<queqiao-_> ⟨v​on Kerman⟩ It's very strange that the burn is taking 8 seconds more than planned. Engine spool up doesn't take that long, there is something else 🤔
<queqiao-_> ⟨q​p⟩ I recall I didn't have such difficulty last time I played with principia about a couple years ago, the major change since then was the residual fuels implemented for RP1, so maybe there's something there? note I'm using the latest builds from ckan, including real fuels that was released earlier today, so maybe there's something there?
<queqiao-_> ⟨v​on Kerman⟩ residuals don't affect the duration of the burn, they only affect how much dV you have left after the burn
<queqiao-_> ⟨v​on Kerman⟩ variance might affect it, but not by 8 seconds I hope
egg|cell|egg has quit [Read error: Connection reset by peer]
<queqiao-_> ⟨v​on Kerman⟩ Not sure about the latest real fuels, don't have it installed yet
egg|cell|egg has joined #principia
<queqiao-_> ⟨D​RVeyl⟩ Are you staging somewhere in there? Principia won't be aware of engines that aren't active while planning the burn.
<queqiao-_> ⟨Q​uadrupole⟩ Pressure-fed engines do have large variances that could lead to an 8 second discrepancy
<queqiao-_> ⟨Q​uadrupole⟩ You probably just had a really bad engine. Blame the contractors.
<queqiao-_> ⟨q​p⟩ yup I'm aware of that, no staging event just a normal burn with aj-10mid
<queqiao-_> ⟨Q​uadrupole⟩ How long was the burn supposed to be?
<queqiao-_> ⟨v​on Kerman⟩ Actually when I think about... 300s rated burn time and 5% variance... 8 seconds doesn't even look like a very large error. Manual burns looking at the map look like the only option (or some really advanced script that doesn't simply wait, but actually counts dV expended and stops when planned DV is reached).
<queqiao-_> ⟨q​p⟩ so the burn was supposed to be about 2m 30sec
egg|cell|egg has quit [Read error: -0x1: UNKNOWN ERROR CODE (0001)]
<queqiao-_> ⟨q​p⟩ I just noticed another weird thing, but not related to principia. this same craft, after the burn, according to MJ has 537 m/s dV remaining. I quicksave and then reload that quicksave and now the craft reports it has a little over 300 m/s remaining. wtf ?
egg|cell|egg has joined #principia
<queqiao-_> ⟨l​pg⟩ that's residuals
<queqiao-_> ⟨l​pg⟩ MJ just gets generally confused by that feature
<queqiao-_> ⟨q​p⟩ shouldn't the number stay the same after reloading though? I haven't activated any engines or rcs, just save and re-load
<queqiao-_> ⟨l​pg⟩ as for needing longer burns, that's not residuals but a feature added at the same time: engine thrusts gets randomized a bit from the nominal value
<queqiao-_> ⟨l​pg⟩ no, that's what confuses it
<queqiao-_> ⟨q​p⟩ so what's the real dV here? if I were to not save /load and just waited for the next maneuver would I get 500ish or 300ish dV ?
<queqiao-_> ⟨l​pg⟩ 500ish is closer to the truth, but there _is_ no real number
<queqiao-_> ⟨q​p⟩ man it was hard to do this a couple years back but now it seems twice as difficult with all these changes, turns out 500ish dV isn't actually enough to get the required Ap/Pe orbit the contract wants so back to the drawing board.. don't get me wrong, I love this new approach, have to build lots of spare room for things like that now, but man I've wasted like 3 days fiddling with this
egg|cell|egg has quit [Ping timeout: 189 seconds]
egg|cell|egg has joined #principia
egg|cell|egg has quit [Read error: Connection reset by peer]
egg|cell|egg has joined #principia
egg|cell|egg has quit [Ping timeout: 189 seconds]
egg|cell|egg has joined #principia
<queqiao-_> ⟨e​gg⟩ Yeah with random variation open loop guidance isn't worth much
egg|laptop|egg has joined #principia
<queqiao-_> ⟨e​gg⟩ I recommend giving your cat a copy of https://twitter.com/eggleroy/status/1123556005042970624
<queqiao-_> ⟨e​gg⟩ @von Kerman declension question: are
<queqiao-_> ⟨e​gg⟩ > Выбрать систем*у* координат
<queqiao-_> ⟨e​gg⟩ and
<queqiao-_> ⟨e​gg⟩ > Выбор систем*и* координат
<queqiao-_> ⟨e​gg⟩ correct?
<queqiao-_> ⟨v​on Kerman⟩ "Выбрать систем*у* координат" or "Выбор систем*ы* координат" are correct.
<queqiao-_> ⟨v​on Kerman⟩ "Выбрать систем*у* координат" and "Выбор систем*ы* координат" are correct. (edited)
<queqiao-_> ⟨e​gg⟩ oh right I was reading the wrong table, системи is Ukrainian
<queqiao-_> ⟨e​gg⟩ @von Kerman FYI I think nodal period is Период драконический, see https://mash-xxl.info/page/216018150022200205220216000154152116019112201159/
<queqiao-_> ⟨v​on Kerman⟩ "draconic period" 🙂
<queqiao-_> ⟨e​gg⟩ yup, both exist in english too, but nodal is more common in english
<queqiao-_> ⟨e​gg⟩ same with draconitique vs. nodale in french
<queqiao-_> ⟨e​gg⟩ hm, Узловой период seems to be a thing too actually
<queqiao-_> ⟨e​gg⟩ but while Драконический оборот is attested, Узловой оборот is not...
<queqiao-_> ⟨e​gg⟩ "драконический период" 3200 results, "узловой период" 654 results
<queqiao-_> ⟨e​gg⟩ "draconic period" 2760 results, "nodal period" 11900 results
<queqiao-_> ⟨e​gg⟩ "période draconitique" 544 results, "période nodale" 3320 results
<queqiao-_> ⟨e​gg⟩ @von Kerman so my conclusion is that while *узловой период* is attested (in particular in some UN documents), it is not the idiomatic technical term in Russian, and instead is a calque of the term in other languages (that would explain prominent appearance in UN documents where it probably is a translation).
<queqiao-_> ⟨e​gg⟩ We should therefore use драконический период.
<queqiao-_> ⟨v​on Kerman⟩ I see, I didn't know this term, but if it exists we should use it.
<queqiao-_> ⟨e​gg⟩ the russians like their dragons
<queqiao-_> ⟨e​gg⟩ I think for recurrence we might want повторение, see период повторения in https://www.itu.int/myitu/-/media/Publications/ITU-News-Magazine/2019/Ru---Monitoring-our-changing-planet.pdf
egg|cell|egg has quit [Ping timeout: 189 seconds]
<queqiao-_> ⟨v​on Kerman⟩ Период повторения sounds good
<queqiao-_> ⟨v​on Kerman⟩ Or just повторение so that it's shorter.
<queqiao-_> ⟨e​gg⟩ there is a small nuance here, and I am going to take that opportunity to eggsplain what this is actually about, the analyser is a strange thing: the Период повторения (lit. *period of the recurrence*) is what Principia calls the cycle, i.e. the duration it takes for the ground track to repeat. We might call that Цикл for brevity and so we can have a Суб-цикл, but I will need
<queqiao-_> ⟨e​gg⟩ The Повторения/Recurrence/Phasage is more abstractly the fact that the ground track repeats.
<queqiao-_> ⟨e​gg⟩ In practice the UI will say that the orbit has a Повторения/Recurrence/Phasage of [νₒ; Dᴛₒ; Cᴛₒ], whereas you could say that it has a Период повторения (cycle) of Cᴛₒ days (or equivalently Nᴛₒ = νₒ + Dᴛₒ / Cᴛₒ revolutions).
<queqiao-_> ⟨e​gg⟩ Magic trick for figuring out the translation of *equatorial shift*: Google орбита ресурс "2819 км"
<queqiao-_> ⟨v​on Kerman⟩ Google search leads to this text, which probably contains the terms that you need: орбита с 14-суточным периодом изотрассового прохождения, витковыми и суточным смещениями, соответственно равными 2819 км и 605 км на экваторе.
<queqiao-_> ⟨e​gg⟩ eggsactly
<queqiao-_> ⟨e​gg⟩ and
<queqiao-_> ⟨e​gg⟩ > Эта орбита была реализована для КА «Ресурс-О1» № 4. Она соответствует высотному диапазону метеорологического КА NOAA (США) и природоресурсного КА Spot (Франция).
<queqiao-_> ⟨e​gg⟩ its use for Ресурс is mentioned in Capderou, which is how I came up with the magical search query :D
<queqiao-_> ⟨e​gg⟩ So витковыми смещениями на экваторе seems to be equatorial shift?
<queqiao-_> ⟨v​on Kerman⟩ "Витковое смещение на экваторе"
<queqiao-_> ⟨e​gg⟩ (ah yes I forgot about case)
<queqiao-_> ⟨e​gg⟩ I don’t think we report the value corresponding to those 605 км though.
egg|laptop|egg has quit [Remote host closed the connection]
egg|cell|egg has joined #principia
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia
UmbralRaptor has quit [Remote host closed the connection]
UmbralRaptop has joined #principia
UmbralRaptop has quit [Client Quit]
egg|laptop|egg has quit [Remote host closed the connection]
egg|laptop|egg has joined #principia