00:02 <discord-> e​gg. — @rsparkyc if you're in space centre view, the prediction is neither shown nor computed, so those settings do nothing

00:02 <discord-> e​gg. — that's specifically about map view/tracking station with a vessel selected

08:57 <discord-> S​tandecco. — @egg I'm trying to make a HST experiment, should it have a minimum altitude?

08:58 <discord-> S​tandecco. — these are the current parameters, based on the current Hubble orbit```OrbitMinInclination:28,

08:58 <discord-> S​tandecco. — OrbitMaxInclination:29,

08:58 <discord-> S​tandecco. — OrbitMaxEccentricity:0.001,

08:58 <discord-> S​tandecco. — AltitudeMax:545000```

08:58 <discord-> S​tandecco. — I'm not that sure about inclination since it was probably chosen just because of vehicle performance

09:22 <discord-> e​gg. — that seems way too constrained

09:23 <discord-> e​gg. — how are those numbers related to mission constraint

09:23 <discord-> e​gg. — how are those numbers related to mission constraints (edited)

09:28 <discord-> S​tandecco. — Hubble eccentricity is something like 0.00028

09:28 <discord-> S​tandecco. — so it must be very important to them

09:29 <discord-> S​tandecco. — Max altitude also is because of the radiation belts

10:34 <discord-> e​gg. — @Standecco > so it must be very important to them

10:34 <discord-> e​gg. — don't draw hasty conclusions

10:34 <discord-> e​gg. — it may be that what is important is, e.g., a frozen orbit, or something

10:35 <discord-> e​gg. — @Standecco Ask UmbralRaptor maybe, but "constrain close to the chosen parameters" is almost invariably completely out of line with actual mission constraints

10:35 <discord-> e​gg. — (see also the many things that were made usable even though they were launched in non-nominal orbits)

10:37 <discord-> e​gg. — @Standecco I think for HST in particular, one of the constraints is serviceability; that's something you could model by having the thing repairable and able to fail, but isn't specific to a particular orbit (since the way serviceability constrains the orbit will depend on the launch site and vehicles of the servicing missions)

10:40 <discord-> S​tandecco. — I could put a maximum amount of radiation

10:40 <discord-> S​tandecco. — so you would be inclined to put it an orbit that doesn't pass through the belts

10:41 <discord-> S​tandecco. — is the only reason they put it in a 540km orbit decay?

12:13 <discord-> S​ir Mortimer. — I suspect they went as high as possible while remaining as low as needed for the shuttle. Higher = less decay & moar exposure time

12:18 <discord-> S​tandecco. — and slower telescope

12:18 <discord-> S​tandecco. — so easier pointing

13:44 <discord-> e​gg. — @Standecco > easier pointing

13:44 <discord-> e​gg. — no, the speed of the telescope with respect to the earth doesn't matter for pointing, it effectively doesn't move with respect to the things it looks at anyway; what does matter is exposure time, but it will very often look out of the plane of the orbit to address that.

13:44 <discord-> e​gg. — The van Allen belts do matter (telescopes essentially can't do their job while in there)

13:44 <discord-> e​gg. — @Standecco but ask UmbralRaptor who actually knows about space telescope

13:46 <discord-> e​gg. — @Standecco but ask UmbralRaptor who actually knows about space telescopes (edited)

13:47 <discord-> S​tandecco. — I'm 100% sure that Hubble has to compensate for its rotation around the earth

13:48 <discord-> S​tandecco. — it has to remain pointed with extreme accuracy over an incredibly small angle, so even a 13k km lateral motion is enough to change that angle

13:48 <discord-> S​tandecco. — especially if it's pointing at closer things

13:56 <discord-> e​gg. — @Standecco for solar system objects it is visible (but anyway you have to correct for the motion of the earth with respect to whatever you are observing so you are not making matters fundamentally different by changing the orbit here). For anything outside the solar system, this baseline is not measureable by Hubble, by a wide margin.

13:58 <discord-> e​gg. — @Standecco but again, ask UmbralRaptor who actually knows about space telescopes; avoid making assumptions on what the design constraints are, because this stuff is generally not obvious

14:01 <discord-> S​tandecco. — maybe I've overestimated Hubble's fov

14:02 <discord-> S​tandecco. — anyway umbralraptor isn't here, how can I ask him?

14:02 <UmbralRaptop> Define here

14:02 <discord-> e​gg. — haha

14:04 <discord-> S​tandecco. — right, the bot

14:04 <discord-> e​gg. — @Standecco Parli del dromaeosauride, ...

14:05 <discord-> S​tandecco. — e spuntano le corna

14:05 <discord-> S​tandecco. — anyway, I have a limited amount of constrains available

14:05 <discord-> S​tandecco. — https://github.com/Kerbalism/Kerbalism/blob/master/docs/modders/modules.rst

14:06 <discord-> e​gg. — @Standecco artigli in questo caso

14:07 <discord-> S​tandecco. — they're all listed here, but the relevant ones are probably radiation, orbital inclination and altitude; I know these aren't the real constrains, but I don't feel like giving the ability to put Hubble in a 150x150 orbit to people

14:07 <UmbralRaptop> HST's orbit choice was driven by STS performance. I guess one could try to compare with that smol Canadian one, or the OAO series

14:08 <discord-> e​gg. — UmbralRaptop: basically, assuming serviceability isn't a concern, what constrains such a thing

14:10 <discord-> e​gg. — @Standecco 150-by-150 will have the obvious problem of decay; a minimal altitude is probably a reasonable way to express that since we currently don't have decay

14:10 <discord-> e​gg. — @Standecco as for inclination, I guess this matters for which parts of the sky are observable (higher inclinations being better if I understand correctly), but I need UmbralRaptop to confirm that I'm not confused

14:12 <discord-> e​gg. — @Standecco also, while 150-by-150 is bad, e.g. an Earth-Sun L2 or earth-trailing orbit don't seem obviously bad for HST, just not at all adapted to the launcher that it used and to servicing

14:13 <discord-> S​tandecco. — I'd love adding a JSWT

14:13 <discord-> e​gg. — so artificial inclination constraints risk preventing perfectly viable orbits in that way

14:13 <discord-> B​utcher. — @egg decay when? 🤔

14:13 <discord-> S​tandecco. — I think that Hubble specifically would've needed additional thermal protection if it were to be positioned in L2

14:14 <discord-> e​gg. — wat

14:16 <UmbralRaptop> Different probably, but HST barely does IR.

14:16 <discord-> e​gg. — yeah IR is a different world

14:16 <discord-> S​tandecco. — so thermal is only a problem for IR?

14:17 <discord-> e​gg. — primarily yes

14:17 <discord-> S​tandecco. — but hubble has some radiators too

14:17 <UmbralRaptop> Technically it's a problem for everything, but only above and beyond normal spacecraft design for IR

14:18 <discord-> e​gg. — @Standecco so does the space station; as UmbralRaptop says, it's not massively different outside IR

14:18 <discord-> e​gg. — in IR it's a nightmare

14:19 <discord-> S​tandecco. — aren't the ISS radiators mainly for getting rid of heat created by internal processes?

14:21 <UmbralRaptop> To contrast with HST, Kepler and TESS are in their orbits so Earth is out of the way more of the time. (This gets into why HST time is measured in orbits)

14:22 <UmbralRaptop> Also note that HST is rather heavy, and TESS in its fancy orbit is the smallest payload a falcon 9 has launched

14:22 <discord-> S​tandecco. — just wanted to brag here

14:22 <discord-> S​tandecco. — https://cdn.discordapp.com/attachments/480397772248580098/599968912376987648/unknown.png

14:22 <UmbralRaptop> er, yes. As were shuttle radiators

14:23 <discord-> S​tandecco. — Io and a vague approximation of the flux tube

14:23 <discord-> S​tandecco. — https://cdn.discordapp.com/attachments/480397772248580098/599969146024886282/unknown.png

14:23 <discord-> e​gg. — yeah, and were it not for launcher/serviceability, HST could be in a TESS-like orbit and would do its job

14:23 <discord-> S​tandecco. — Ganymede and my understanding of its magnetic field

14:23 <discord-> S​tandecco. — https://cdn.discordapp.com/attachments/480397772248580098/599969253453725705/unknown.png

14:23 <discord-> e​gg. — nice belts

14:24 <discord-> e​gg. — cc @bofh453: Jovian magnetic fields

14:24 <discord-> e​gg. — Jovial magnetic fields

14:24 <discord-> S​tandecco. — the fun part is that Io has an environmental radiation of 380 rad/h and Europa of 50 rad/h

14:24 <discord-> S​tandecco. — I've found some sources that go up to 15k rad/day for Europa and some even 30M rad/day

14:27 <UmbralRaptop> Which is more dangerous: standing on the elephant's foot, or Io?

14:28 <UmbralRaptop> (Yay, radiation belts. Well, boo, but still yay)

14:28 <discord-> e​gg. — next up, radiation suspenders

14:29 <UmbralRaptop> Presumably that's the flux tube

14:31 <discord-> S​tandecco. — @egg suspenders?

14:31 <discord-> B​utcher. — Instead of belts. 😆

14:32 <discord-> S​tandecco. — oh lol

14:44 <UmbralRaptop> hrm. what happened to that mission design / orbit choice page?

14:51 <discord-> S​tandecco. — https://github.com/Kerbalism/Kerbalism/wiki/Satellite-Contracts

14:53 <UmbralRaptop> thanks

15:21 <discord-> e​gg. — UmbralRaptop: I haven't made much progress on it but it's still on my radar somewhere

15:55 <UmbralRaptop> I mean, it still has enough research to be useful for this discussion

15:56 <discord-> b​ofh453. — ooh, Jovian magnetic fields

16:02 <discord-> S​ir Mortimer. — So much for my base on io 😦

16:15 <UmbralRaptop> As if the volcanoes weren't enough?

16:46 <_whitenotifier-5dfc> [Principia] pleroy reviewed pull request #2246 commit - https://git.io/fjXE5

16:47 <_whitenotifier-5dfc> [Principia] pleroy reviewed pull request #2246 commit - https://git.io/fjXEd

17:01 <_whitenotifier-5dfc> [Principia] pleroy reviewed pull request #2246 commit - https://git.io/fjXuT

17:26 <_whitenotifier-5dfc> [Principia] pleroy reviewed pull request #2246 commit - https://git.io/fjXuV

17:29 <_whitenotifier-5dfc> [Principia] pleroy reviewed pull request #2246 commit - https://git.io/fjXu1

17:29 <_whitenotifier-5dfc> [Principia] pleroy synchronize pull request #2246: Document an algorithm by Fukushima - https://git.io/fjXnn