02:20 <queqiao-> ⟨Milly⟩ Trying to get the hang of rendezvous with Principia - for some reason I'm finding it really bloody hard. Any advice on how to do it reliably?

03:28 <queqiao-> ⟨pEdro⟩ ⟪Milly⟫ Trying to get the hang of rendezvous […] ⮪ yeah, first, to do it right the first time, you have to be on a orbit that intersects the lunar one in around 3 days of tranfer, those can be gotten with some kos scripts floating about.

03:28 <queqiao-> Then its mostyl just fiddling with tangent and t initial, changing t initial will move you "up" and "down" compared to the moon, vertical to its orbital plane.

03:28 <queqiao-> tangent makes sure you actually get there, 3145m/s is a good starting point

05:00 <queqiao-> ⟨Sumguy⟩ ⟪pEdro⟫ yeah, first, to do it right the first […] ⮪ wrong ping

05:01 <queqiao-> ⟨Sumguy⟩ ⟪Milly⟫ Trying to get the hang of rendezvous […] ⮪ https://github.com/mockingbirdnest/Principia/wiki/A-guide-to-performing-low-orbit-rendezvous

08:03 <queqiao-> ⟨Milly⟩ ⟪Sumguy⟫ https://github.com/mockingbirdnest/Princ[…] ⮪ Oh, I've read through that one, I just can't figure out how to drop relative velocity, which results in me being close, and then the station zooming up and away from me at 260m/s

08:15 <queqiao-> ⟨test_account⟩ 260m/s means the orbits are not very well matched at all

08:15 <queqiao-> ⟨Butcher⟩ ⟪Sewer Clown⟫ Didn't get pinged, my bad, I was trying […] ⮪ MJ can execute principia manoeuvres, alternatively kos can as well, if you have a suitable script.

08:17 <queqiao-> ⟨Butcher⟩ If you're in plane, then usually a tangent burn in the inertial reference frame will slow you down nicely.

08:17 <queqiao-> ⟨Butcher⟩ Which direction depends on if you're coming from a higher or lower orbit. You're basically doing a hohmann transfer into the orbit of the target.

08:36 <queqiao-> ⟨Sewer Clown⟩ Very good knowledge

08:44 <queqiao-> ⟨Butcher⟩ Suppose I should try Hilbert since I'm trying to do a Jupiter MCC.

10:56 <queqiao-> ⟨Butcher⟩ egg Declutter is 😻

11:03 <queqiao-> ⟨Milly⟩ ⟪test_account⟫ 260m/s means the orbits are not very […] ⮪ I'm not sure what the hell I'm doing then - I seem to either be able to get about 10km away with like 10m/s relative velocity, but then I never manage to get closer, or I get within 200m, but the relative velocity is 200m/s

11:04 <queqiao-> ⟨Milly⟩ I'm trying to use the map, but it's just loops and swirls and I have no idea what I'm looking at to actually get closer but not increase the relative velocity :/

11:07 <queqiao-> ⟨test_account⟩ I assume the target's orbit is at least roughly circular and you are in the same plane already?

11:09 <queqiao-> ⟨Butcher⟩ At 10 m/s it;s going to take a while to travel 10km to close...

11:10 <queqiao-> ⟨test_account⟩ but at 260m/s it will take most of say Gemini capsule's dV, you may even run out of fuel

11:15 <queqiao-> ⟨test_account⟩ so, assuming this: for now, try to just make your orbit the same circular orbit with exactly the same orbital period as the target (down to seconds)

11:16 <queqiao-> ⟨test_account⟩ when you've done that, the swirls and loops will turn into one, hopefully small circle

11:16 <queqiao-> ⟨test_account⟩ and then you can play with it to get closer

11:16 <queqiao-> ⟨test_account⟩ (and it helps to understand how the loops and swirls work, it's not the most optimal way to do rendezvous)

11:23 <queqiao-> ⟨Nazfib⟩ ⟪Butcher⟫ At 10 m/s it;s going to take a while to […] ⮪ Not really, actually. Let's take for example a target in a 300 km circular orbit.

11:23 <queqiao-> If you're 10 m/s slower at your apoapsis - that means that you are in a 265x300 km orbit. This orbit has a shorter period by approximately 21 seconds; the result is that you catch up to the target by approximately 165 km horizontal distance per orbit.

11:23 <queqiao-> If you are only 10 km behind, you actually want to _reduce_ your relative velocity to intercept after one orbit.

11:23 <queqiao-> ⟨Nazfib⟩ -If you are only 10 km behind, you actually want to _reduce_ your relative velocity to intercept after one orbit.

11:33 <queqiao-> ⟨Milly⟩ ⟪test_account⟫ I assume the target's orbit is at least […] ⮪ Yep, got that far - I was trying to do it like with stock - the station was behind me, so I went into a higher orbit with the Soyuz to allow the station to catch me

11:34 <queqiao-> ⟨Nazfib⟩ That is basically the trick to low-dV orbital rendez-vous while in the same orbital plane - starting from the same orbit,

11:34 <queqiao-> - if you're _behind_ the target, _slow down_ to _reduce_ your orbital period (making you catch up to the target)

11:34 <queqiao-> - if you're _ahead_ of the target, _speed up_ to _increase_ your orbital period (making the target catch up to you)

11:36 <queqiao-> ⟨Nazfib⟩ Then eventually, in one of the orbits, you overtake the target (the target overtakes you) - at the apoapsis (periapsis) before this happens, burn prograde (retrograde) to reduce the difference between the two orbits and you should be able to get close with a very low relative velocity.

11:39 <queqiao-> ⟨test_account⟩ And the loops and swirls show this process. It is the relative distance between you and the target. When you are in the same orbit with same period, but in different "places" - they turn into a closed loop or ideally a point, meaning that relative distance does not change. Try burning prograde or retrograde at that point and you will see the loops going toward the target or away from it, and this is how you get closer.

11:39 <queqiao-> ⟨Nazfib⟩ Exactly.

12:23 <queqiao-> ⟨Milly⟩ 👍

22:39 <_whitenotifier-81d9> [Principia] pleroy opened pull request #3418: Add potential computation to DynamicFrame - https://github.com/mockingbirdnest/Principia/pull/3418