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…
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<queqiao->
⟨charon_s.⟩ Currently no. But I might try to turn some asteroidal moons into stock potatoroids. In that case their orbit will be changeable
<queqiao->
⟨sichelgaita⟩ Note that this would make it a lot more costly in CPU: potatoroids, being vessels, are integrated every 10 s; celestials are integrated every 10 min.
<queqiao->
⟨kaborl⟩ Hey everyone, when using the Lunar Transfer window, do we need to launch at 0s of the window, or at a different time? Thanks.
<queqiao->
⟨kaborl⟩ There's something I don't get about the Launch Now Incl. If I want until 0s, it says 28.55 degree. However, if I wait another second then it says -28.55 degree. Which one is the correct one?
<queqiao->
⟨GoForPDI (less drag=more faster)⟩ Effectively as you pass the desired time it now wants to launch southeast instead of northeast. That’s all that means
<queqiao->
⟨kaborl⟩ I might be missing something about the inclination, but shouldn't 28.55 degree + too late launch result in a slighly different inclination? Or, are -28.55 and 28.55 "almost the same" somehow?
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<queqiao->
⟨kaborl⟩ * "28.55 degree + too late launch result" in a slightly
<queqiao->
⟨vlood⟩ -28.55 and 28.55 are the same inclination, different launch azimuths
<queqiao->
⟨test_account9540⟩ Launch azimuth should be the same... due east
<queqiao->
⟨test_account9540⟩ though there might be a little difference? just a little but one goes very slightly north and another goes very slightly south 🤔
<queqiao->
⟨Damien⟩ Does the launch time change? Because a North launch would be a south launch 12hrs later into the same orbit
<queqiao->
⟨lpg4999⟩ when the target inclination calls for a due-east launch, "north launch" and "south launch" are exactly the same thing
<queqiao->
⟨lpg4999⟩ (when the target inclination calls for only slightly-north and slightly-south launch, the two will be only a short time apart, not 12h)
<queqiao->
⟨lpg4999⟩ * or
<queqiao->
⟨test_account9540⟩ But it almost never calls exactly for a due-east launch? " Launch Now Incl. " changes constantly and you (or PVG) almost always need to follow a northeastern or maybe southeastern trajectory 🤔
<queqiao->
⟨lpg4999⟩ it calls for "exactly" due-east when you actually wait for the time to reach zero
<queqiao->
⟨test_account9540⟩ Yes, so technically never, it's impossible to catch the exact moment
<queqiao->
⟨lpg4999⟩ yes, and for pointless pedantry like this, you use by "a short time apart" statement
<queqiao->
⟨lpg4999⟩ * my
<queqiao->
⟨test_account9540⟩ I'm just trying to understand 28.55 and -28.55 when in fact not much has changed
<queqiao->
⟨lpg4999⟩ positive: launch north of due-east. negative: launch south of due-east
<queqiao->
⟨lpg4999⟩ when it crosses through due-east, it's neither north nor south. 28.55 and -28.55 are the same thing
<queqiao->
⟨lpg4999⟩ remember that "-28.55 inclination" doesn't _mean_ anything IRL, it's entirely a MJ invention to express that north-vs-south distinction
<queqiao->
⟨lpg4999⟩ (now lamont shows up to point out MJ didn't invent that convention itself)
<queqiao->
⟨test_account9540⟩ But these numbers are given by TWP. Either TWP follows a MJ "convention", or the "-" arises naturally from some formula
<queqiao->
⟨lpg4999⟩ _LTP_, written by butcher, was written to be useful in ksp, when using MJ
<queqiao->
⟨lpg4999⟩ so yes of course it follows its convention
<queqiao->
⟨test_account9540⟩ * ~TWP~Lunar Transfer Planner, my bad.
<queqiao->
⟨nazfib⟩ TWP does not show negative inclinations. LTP deliberately uses the MJ "convention".
<queqiao->
⟨test_account9540⟩ * ~TWP~LTP
<queqiao->
⟨lpg4999⟩ TWP uses the sensible "LAN+inclination" way of describing an orbit.
<queqiao->
⟨lpg4999⟩ (TWP doesn't care how you get into that orbit; if the target inclination is higher than your lattitude, you're the one choosing a northerly vs southerly launch when inputting numbers in PVG)
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<queqiao->
⟨kaborl⟩ Is it me or there's a random bug where sometimes markers get randomly stuck somewhere and can't be removed?
<queqiao->
⟨kaborl⟩ A simple Moon return to Earth. One can clearly see here how unintuitive it is and how simplified the Conic Patches model is in KSP. I'm praising the excellent work that the KSP1 devs did with the stock orbital mechanics, because they managed to simplified in a way that it can be consumed by idiots like me. Principia might be emulating Real-RSS and have closer approximations to reality. But oh boy isn't it weird! Thanks Principia to...
<queqiao->
⟨egg⟩ And as you are being told, ECI (let alone GSE!) is not a useful way to look at your trajectory close to the moon; so things look confusing because you have chosen a confusing way to look at them. Please read the tooltips on the reference frame selector and the concepts page.
<queqiao->
If you care about the Moon, you should use a reference frame where the Moon isn’t running away (so MCI, or, since you also care about the earth, EML or MEO).
<queqiao->
⟨egg⟩ I think it is indeed a completely straightforward high-energy trajectory, except the bit around the moon is unreadable in the chosen reference frame.
<queqiao->
⟨clayel⟩ why doesnt it simulate it?
<queqiao->
⟨clayel⟩ oh wait sorry its due to galaxy peturbations not planet peturbations, mb