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Author Topic: The ISS, Mir, and Skylab LEOs  (Read 3994 times)

ShoeUnited

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The ISS, Mir, and Skylab LEOs
« on: April 12, 2012, 04:31:29 AM »
As mudkipz made mention, plotting the International Space Station would be awesome. :D
But it was a project that was not without strife.  -_-;  If you want to skip to the data needed to run just ignore the parts between the dashes.

Skip the bold section if you're not interested in the back story.

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First I decided I'd pick the ring out of the Objects bin.  Because what is more awesome than a ring (I know the ISS is about as ring shaped as a sheet of paper :P). 

Then it was time to the internet.  And hard data was almost nil.  I was shocked!  Finally I came upon a NASA facts page about the ISS.  Which gave me a rough estimate of age, distance traveled in that time period, and orbits completed.  Not what I wanted, but I figured it'd do me well enough to get some rough math working.  Already the project had ballooned from 15 minutes to 2 hours.  And no sooner do I get done and go online to check my figures, when what do I find?  A NASA facts page... with different numbers.  :|  A difference in roughly 200 million miles and 11,000 orbits...  So much for "Facts and Figures"
http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html
http://www.nasa.gov/mission_pages/station/main/onthestation/index.html

So! Let's redo math.  Ok, not bad, not bad.  I know I'm missing some numbers, but I should have enough for a boat show.  I punch in the numbers I got and run the simulation.  And the 'Station' isn't looking right.  I know it.  So I decide to adjust its trails so I can see if the trajectory accumulates over time.  Oops, too much trajectory mapping.  And then it crashed.  But it didn't crash hard.  It tells me that it will crash with an unrecoverable error.  Would I like to reload?  Yes, please!

And suddenly, my ring is an asteroid.  :l   At the time I didn't know how to change its model.  Researched that.  Didn't find much into which is what models (I did find it out later on accident).  So I figured "Well, let's just make a custom texture for it.  Everyone does it. :D"  So, I opened up Gimp, made a copy of the texture that is generated so that I had a reference for scale and went to editing.  Time passes.  Get what I think is good, then change it a couple times.  Good. :D

As I'm looking around, I went to wiki for the ISS logo.  DATA! :O  And... it doesn't agree with my calculations.  :l  And it's incomplete.  (srsly?)  Go to wolframalpha (<3 <3 <3) and find out they have data on the ISS ( ;D).  Compare it to my calculations and mine are only different by a few hundreths.  :D  Things are looking up!

So I go and decide that since I've got half the data I want but enough to make something look O.K. that I may as well throw on other space stations.  I pick Mir and Skylab and Salyut.  Gonna be some happy day.  There is like, almost 0 data on Salyut.  :c  Sorry you gotta go.  Mir and Skylab are almost equally bare.  IDC at this point the difference in data between Mir and ISS is almost negligible.  I just eyeball Mir and Skylab so that they don't collide in their orbits.  Make some more textures and things are looking good.  :D

But ISS is still bothering me.  That kind of data should be available.  NASA should have enough data online that I could do everything short of building it in the backyard (it's kinda big).  Looking, looking, finding nothing.  Kinda disappointed.  Decide that if I can at least get the perigee I'd be happy.  Suddenly, 5 pages deep on google:  http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html  EXACTLY WHAT I WANTED IN THE FIRST PLACE! D:

Punch in the first set of numbers and run.  Something doesn't look right.  It doesn't seem to be moving as it orbits.  Sure it orbits, but I mean it should drift as it orbits so that it doesn't keep tracing the same path over and over.  As I watch it, I decide to punch in the last set of numbers on the 3 station system and it's the same thing.  I don't know if this is a limitation of the software, or if its movement is so negligible that it'd take a while.  I am running at 1sec = 100x (which is plenty fast believe me).   So, I guess that remains to be seen. 

Enough ranting without further ado.

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Hey! If you skipped down here I still wanna talk to you.  Do NOT set the timestep too high.  15 minutes will result in everything going flying.  You need to keep it at or under 2 minutes.  Or if you do 1sec = try to keep it below a couple thousand.

Also, turn off auto trails.  If you want trails, I suggest 10, 50, 100, 200.  But not more than 500, it will break your stuff up.

I'm also including my textures here as well as adding them to the texture thread.  I know the ISS symbol is screwy when put on a globe, but I was getting tired and didn't feel like resizing it to make it look less wonky. The names are weird because if you try to reload a texture without quitting US2, it will load what is in cache.  So I made duplicates of the files I was editing.

The ISS is in a different area on the 3 station .ubox file because of its drift.  The mean numbers I took from NASA themselves and the positions reflect where it moved to in different time frames.  So don't be alarmed.
The data is available for reading here:  http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html  Take note of the first and last sets of data. 

Things are properly named as usual for ease of using the wiki tool to educate. :D  I hope you enjoy checking out our largest man made satellites and educate yourself and others. 

Not having these textures will leave you with some good old apopsis texture.  So grab the textures.  They put it in the spirit of things.  Also note, these are the official logos for their programs.  Yes, really, that's Skylab's logo.

Finally, thanks mudkipz for the idea.  ^-^ If you wanna discuss it further, I'd be happy to.  I'm just too tired to go into detail right now.

Finally, finally, the eye candy :D  Enjoy!