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poliastro

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Chat about poliastro, a Python library for Astrodynamics http://docs.poliastro.space4 Servers

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Timestamp Message
29 Nov 2018
09:37:10@astrojuanlu:matrix.orgastrojuanluWell, if you know Java already then Orekit is the way to go
09:37:41@astrojuanlu:matrix.orgastrojuanlu But changing the library before assessing where the bottleneck or slowness is, it's unwise I would say
09:41:42@eaf:matrix.orgeafi have literally zero idea how to use java
09:42:47@eaf:matrix.orgeafthe slowness is coming from that i have to draw and propagate the orbit hundreds of times, so i can sort of get a hacky version of the plot.trajectory working
09:44:37@eaf:matrix.orgeafi would be able to make it run so much faster if i could
09:45:09@eaf:matrix.orgeaf- plot the trajectory from t1 to t2 on an orbit
09:45:15@eaf:matrix.orgeafand
09:45:35@eaf:matrix.orgeaf- return orbit propagated up to t2
09:45:45@eaf:matrix.orgeafbut that frame bug thing just wont let me do it
09:49:39@astrojuanlu:matrix.orgastrojuanlu Then, please report it at https://github.com/poliastro/poliastro/issues/new and we'll look into it :)
30 Nov 2018
08:28:56@eaf:matrix.orgeafhow do I pull the apopasis/periapsis data from an orbit object(?) ?
08:29:04@eaf:matrix.orgeafi.e 2530 x 20957 km x 0.0 deg (MercuryICRS) orbit around Mercury (☿) at epoch J2000.000 (TT)
08:33:45@eaf:matrix.orgeafnevermind, got it
08:46:41@eaf:matrix.orgeaf(orbit.r_a.value for anyone wondering)
10:29:30@eaf:matrix.orgeafquestion, does poliastro have a nice function for time to (peri/apo)apse?
14:19:27@astrojuanlu:matrix.orgastrojuanlu eaf: not really, but it would be nice to have...
14:20:13@astrojuanlu:matrix.orgastrojuanlu you can do nu_to_M(orbit.nu) / orbit.n?
14:20:28@astrojuanlu:matrix.orgastrojuanlu(off the top of my head, didn't really think of it)
16:11:17@eaf:matrix.orgeafi should really have done the maths on this problem before i set out at it
16:11:34@eaf:matrix.orgeafi think my code is working now, however, it's not right for a 15+ hour insertion burn to mercury
16:12:12@eaf:matrix.orgeafi need to be able to somehow vary the angle of burn in order to keep the periapsis up above the surface of mercury the whole way into the approach
16:36:54@astrojuanlu:matrix.orgastrojuanluNon tangential burns will be tricky :)
16:42:43@eaf:matrix.orgeafvery tricky, i think i may be in over my head here
17:17:45@eaf:matrix.orgeafmaybe if I split it out into two maneuvers?
17:18:16@eaf:matrix.orgeafone radial burn at the very start to shift the periapsis out high enough that i dont hit mercury on the retroburn
17:18:47@eaf:matrix.orgeafthen have my minimiser optimise the time and duration of the two burns
17:18:57@eaf:matrix.orgeafso like (end orbit accuracy)*fuel burn
17:24:00@eaf:matrix.orgeafthis went from a 2d problem to a 4d one
18:11:27@eaf:matrix.orgeafI might be able to do it with a PID controller?
5 Dec 2018
13:40:07@astrojuanlu:matrix.orgastrojuanluHi everyone! My work peak has ended (finally) so I hope I can take care of some poliastro pending things during the following days and weeks

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