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…
<_whitenotifier-81d9> [Principia] pleroy opened pull request #3344: Eliminate the reference part and use Davenport's Q Method instead - https://github.com/mockingbirdnest/Principia/pull/3344
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ How do I figure out at what days I can launch efficiently to the moon?
<queqiao-> ⟨Stonesmile⟩ By using kOS, butcher has a script for every second, itsRyan has one that gives one per day launching east
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ kOS, at least in the past, has made my install unstable
<queqiao-> ⟨Stonesmile⟩ Kourou then?
<queqiao-> ⟨Quadrupole⟩ ⟪QeDelphyn (Xšayāršā/-ām/-āyā)⟫ How do I figure out at what days I can […] ⮪ Enter the launch scene four or five days before any date on this list. Then use PVG to launch into the LAN of the moon.
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ ⟪Quadrupole⟫ Enter the launch scene four or five […] ⮪ thanks
<queqiao-> The CSV file linked by Quadrupole above calculates when this case occurs:
<queqiao-> >Your own orbit's LAN is only equal to the Moon's LAN relative to the Earth's equator, [...] if the Moon is currently ~3-5 days before it's AN/DN relative to the Earth's equator (this means that you intercept the Moon when it is at that equatorial AN/DN).
<queqiao-> which gives you a launch window twice a month. There are launch windows twice a day, but these are more difficult to find the LAN for.
<queqiao-> The CSV file linked by Quadrupole above calculates when this case occurs:
<queqiao-> > Your own orbit's LAN is only equal to the Moon's LAN relative to the Earth's equator, [...] if the Moon is currently ~3-5 days before it's AN/DN relative to the Earth's equator (this means that you intercept the Moon when it is at that equatorial AN/DN).which gives you a launch window twice a month. There are launch windows twice a day, but these are more difficult to find the LAN for.
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ launch opportunities twice a month are fine for me for now.
<queqiao-> ⟨Nazfib⟩ Fair enough, it is one of the easiest methods I've seen floating around here.
<queqiao-> ⟨Quadrupole⟩ The bimonthly windows also have lower relative inclination, so you get (20 m/s for Cape, 50 m/s for Baikonur or higher) cheaper insertions.
<queqiao-> ⟨Nazfib⟩ ⟪Quadrupole⟫ The bimonthly windows also have lower […] ⮪ That's also a consideration, if your margins are small. Though I believe that only one of the bimonthly windows has the minimum relative inclination; the other will actually have the _maximum_ rel.inc.
<queqiao-> ⟨Quadrupole⟩ I mean, when you match LAN with the moon, you minimize relative inclination, _and_ intercept the moon at either of its nodes.
<queqiao-> You get the max relative inclination when you intercept the moon exactly between the nodes.
<queqiao-> ⟨Quadrupole⟩ +So the two windows are equally good.
<queqiao-> ⟨Quadrupole⟩ * ~You get the max relative inclination when you intercept the moon exactly between the nodes.~
<queqiao-> ⟨Nazfib⟩ Oh wait, yes, I was thinking of the case where your LAN is the Moon's LDN, but then your LAN's are 180° away from eachother.
<queqiao-> ⟨Quadrupole⟩ Btw, there is an Excel prototype I made to calculate the bidaily windows. I plan to make it a website calculator, but that will come soon™
<queqiao-> ⟨Nazfib⟩ (That's actually the other daily launch window on those days, 12h earlier/later)
<queqiao-> ⟨Quadrupole⟩ Btw, there is an Excel prototype I made […] ⮪ Oops, forgot to specify which nodes are ascending in my previous list. Here is an updated version.
<_whitenotifier-81d9> [Principia] pleroy commented on pull request #3344: Eliminate the reference part and use Davenport's Q Method instead - https://github.com/mockingbirdnest/Principia/pull/3344#issuecomment-1086886986
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ ⟪Quadrupole⟫ Oops, forgot to specify which nodes are […] ⮪ does it matter whether the node is ascending or descending?
<queqiao-> ⟨Nazfib⟩ Not really, the only difference is whether you coast for 1/4 orbit (DN) or 3/4 orbit (AN) before TLI (assuming a launch from the northern hemisphere)
<queqiao-> ⟨Nazfib⟩ * (AN) or 3/4 orbit (DN)
<queqiao-> ⟨Quadrupole⟩ It only matters for bidaily windows, hence I quoted my calculator.
<_whitenotifier-81d9> [Principia] eggrobin commented on issue #2519: Spin-up on reentry under physics warp with FAR - https://github.com/mockingbirdnest/Principia/issues/2519#issuecomment-1086908148
<queqiao-> ⟨QeDelphyn (Xšayāršā/-ām/-āyā)⟩ when principia calculates the trajectories resulting from a burn, does it assume the burn starts at the selected time, end at the selected time or halfway?
<queqiao-> ⟨pEdro⟩ It starts at the selected time
<queqiao-> ⟨pEdro⟩ the name gives it away
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