raptop changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> egg|nomz|egg: generally if your eyes are dewing over, that's not the weather. | <ferram4> I shall beat my problems to death with an engineer. | We can haz pdf
<mofh>
23:41:18 <@egg|z|egg> how do i describe satellite orbits in the presence of weird perturbations that i potentially can't model without being eaten by a singularity when e is smol
<mofh>
i feel like you're now getting into "reimplementing NASA HORIZONS" levels of compleggsity
<egg|z|egg>
what? no, HORIZONS doesn't do anything interesting
<egg|z|egg>
its elements are all osculating and boring
<B787_300>
Mofh more like getting close to GMAT
<egg|z|egg>
mofh: and its ephemeris hodgepodge not really nicely documented/choosable like the ИПА РАН orIMCCE ones
<egg|z|egg>
honestly at this point if you need anything from HORIZONS that relates to the planets and their natural satellites I would recommend running away from JPL and towards either of the other two
<egg|z|egg>
IMCCE recently redesigned their ephemeris formular
<mofh>
I mean I mostly use HORIZONS for spacecraft ephemerides
<mofh>
But yeah, agreed, I've switched to IMCCE for most everything else.
<galois>
title: AIAC18: 18th Australian International Aerospace Congress (2019): HUMS - 11th Defence Science and Technology (DST) International Conference on Health and Usage Monitoring (HUMS 2019): ISSFD - 27th International Symposium on Space Flight Dynamics (ISSFD) - Accurate osculating/mean orbital elements conversions for spaceborne formation flying (Engineering Collection) - Informit
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<_whitenotifier-5dfc>
[Principia] pleroy opened pull request #2186: Next release is Fermat - https://git.io/fj0wi
<galois>
[WIKIPEDIA] Dongfeng (missile) | "The Dongfeng (simplified Chinese: 东风; traditional Chinese: 東風; literally: 'East Wind') series, typically abbreviated as "DF missiles", are a family of short, medium, intermediate-range and intercontinental ballistic missiles operated by the Chinese People's Liberation Army Rocket Force (formerly the..."
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<UmbralRaptor>
Is this how the missile knows where it is?
<egg|z|egg>
!u -f
<galois>
-: U+002d HYPHEN-MINUS
<galois>
f: U+0066 LATIN SMALL LETTER F
<egg|z|egg>
UmbralRaptor: where it isn't, too
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<galois>
title: Eric Mamajek on Twitter: "Astro PhD student opportunity: IPAC Visiting Graduate Fellowshiphttps://t.co/6DnfXElM1C"six-month positions to graduate students who want to conduct PhD-level astronomical research in close association with @caltechipac scientists." #exoplanets #NASA #astronomy #AAS #STEM"
<SnoopJeDi>
IPAC?
<SnoopJeDi>
!acr -add:IPAC International Particle Accelerator Conference
<galois>
Definition added!
<SnoopJeDi>
!acr -add:NAPAC North American Particle Accelerator Conference
<galois>
Definition added!
<SnoopJeDi>
IUPAC?
<SnoopJeDi>
!acr -add:IUPAC International Union of Pure and Applied Chemistry
<galois>
Definition added!
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<egg>
SnoopJeDi: are you able to haz pdf on that australian paper?
<galois>
title: AIAC18: 18th Australian International Aerospace Congress (2019): HUMS - 11th Defence Science and Technology (DST) International Conference on Health and Usage Monitoring (HUMS 2019): ISSFD - 27th International Symposium on Space Flight Dynamics (ISSFD) - Accurate osculating/mean orbital elements conversions for spaceborne formation flying (Engineering Collection) - Informit
<SnoopJeDi>
hmm it doesn't automagically retrieve it but let me check
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<SnoopJeDi>
egg, nope, I'd recommend emailing G. Gaias directly and asking her for a copy. I do have access to some papers that look related, but I assume you know that what you need is only in that paper
<egg>
I have no idea what I need
<SnoopJeDi>
egg, hmm, what drew you to that paper?
<SnoopJeDi>
(I didn't check scrollback)
<egg>
things wot cite the GSOC/DLR paper mentioned further up
<egg>
that develops a mean element theory for GSOC while complaining that the existing modern ones are hidden in JPL internal documents
<egg>
Precise mean orbital elements determination for LEO monitoring and maintenance
<egg>
tbh that one probably has anything I actually need
<SnoopJeDi>
sounds like the AIAC18 paper is a solid bet, then
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<SnoopJeDi>
gabriella.gaias@polimi.it looks like a good email at which to reach her
<egg|cell|egg>
Snoopjedi: unlikely to be worth the hassle, Precise mean orbital elements determination for LEO monitoring and maintenance probably is more relevant to what I want to poke at
<egg|cell|egg>
And that one is easy to get
<SnoopJeDi>
Fair enough
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<egg|cell|egg>
(worst case 8 AUD is cheap if I'm reading that price rise right)
<SnoopJeDi>
yea that's decently fair, although at that point an email is worth hassle unless it's a fire that needs immediate putting out :P
<SnoopJeDi>
and also presumably DLR people can point the way to whatever you do need if the paper is not quite it
<egg|cell|egg>
You seem to think I know what I need
<SnoopJeDi>
I usually make that assumption, but I think it's not unreasonable to ask to pick someone's brain, either.
<SnoopJeDi>
but also it's not unreasonable to continue surveying the literature until you can form a question you're comfortable with
<SnoopJeDi>
And I have full faith you know how to navigate that space to your own satisfaction, just wanted to toss out the reminder that human beings write papers and they're _usually_ nice, it's too easy to forget :)
<egg|cell|egg>
My questions are generally weird, ill defined, and open at this point
<SnoopJeDi>
Breakfast of champions in academia :D
<SnoopJeDi>
but yea, I know that feel. I sometimes wonder if I'll ever have a well-formed idea.
<egg>
KSP is good at inducing weird questions, usually when doing mission design you know what the planet is
<egg>
or ferram4's problems, usually aerodynamicists don't have to deal with recomputing models in real time as bits of the plane fall off
<egg>
also they deal with planes that look like planes
<SnoopJeDi>
I remember ending up in some ascent profile white papers when trying to get my head around the Trajectories mod including aerodynamic effects
<SnoopJeDi>
Not particularly deep though. You're right though, it's a good generator of lines of inquiry. Such is exploration?
<egg>
eggsploration
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<SnoopJeDi>
right you are
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<egg>
UmbralRaptop: mofh: B787_300: I'm wondering what useful properties I can compute and give about a perturbed Keplerian orbit without modeling the perturbations
<galois>
title: Gemini IX Crew Found 'Angry Alligator' in Earth Orbit | NASA
<B787_300>
No idea
<SnoopJeDi>
what a title
<egg>
B787_300: if the orbit is the tiniest bit inclined (and if it isn't perturbations will probably make sure it is), mean node-to-node times (nodal period) should be well behaved, and then you can talk about phasing and stationkeeping of the longitude of equatorial crossing
<egg>
computing ω, ω', and the anomalistic period as mean periapsis-to-periapsis time otoh fails completely for low-eccentricity orbits (the 4-apsis orbits)
<egg>
the sidereal period (mean time between crossings of a plane perpendicular to the equator) should be well behaved inconditionally, but isn't very useful
<egg>
all the cycle wrt the sun / sun-synchronicity stuff is tied to the nodal precession so that might work too
<B787_300>
UmbralRaptop: is nasa really killing Spitzer
<UmbralRaptop>
Yes
<egg>
aaaaaaaaa
<UmbralRaptop>
I think there was some swapping around funding with NSF?
<B787_300>
At least jwst made it out of tvac okay
<egg>
tvac?
<UmbralRaptop>
Thermal vacuum chamber/testing
<B787_300>
Thermal vacuum
<egg>
mofh: B787_300: UmbralRaptop: another way to approach the question: which quantities are you *directly* interested in when describing an orbit
<B787_300>
Egg the 6 classical. Plus their movement terms.
<egg>
by *directly* I mean e.g. probably not the eccentricity, because here it's likely the apsis altitudes that are of interest rather than the description of their ratio
<UmbralRaptop>
hrm
<egg>
and Ω is almost certainly of no direct interest
<egg>
(because Ω' is nonzero, so interesting alignment of the ascending node would more likely be on the ground track, with a terrestrial longitude, or with a mean solar time for sun-synch orbits)