#4060246 - 01/06/15 01:55 AM
SpaceX going for a first ever tomorrow
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piper
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#4060255 - 01/06/15 02:13 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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WileECoyote
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Holy crap! That's way cool.
When you're feeling sad, just remember that somewhere in the world, there's someone pushing a door that says "pull".
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#4060261 - 01/06/15 02:25 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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Peally
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They're our main space exploration right now, more power to them I hope it goes well.
Scully: Victim died of multiple stab wounds. Mulder: *throws her a file* Ever heard of the knife alien?
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#4060297 - 01/06/15 06:25 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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adlabs6
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Fantastic stuff. I hope it works!
WARNING: This post contains opinions produced in a facility which also occasionally processes fact products.
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#4060300 - 01/06/15 06:52 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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Weaponz248
Hail To The King Baby!!
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Hail To The King Baby!!
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Awesome! I hope it works. Quick question, According to this picture, the reentry is basically 90 degrees to earth, I thought you had to enter the atmosphere at a different angle.
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#4060360 - 01/06/15 01:27 PM
Re: SpaceX going for a first ever tomorrow
[Re: DaBBQ]
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Weaponz248
Hail To The King Baby!!
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Hail To The King Baby!!
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Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path. Ah Gotcha! Thanks makes sense now.
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#4060370 - 01/06/15 01:55 PM
Re: SpaceX going for a first ever tomorrow
[Re: DaBBQ]
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Peally
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Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path. Air compression, not friction
Scully: Victim died of multiple stab wounds. Mulder: *throws her a file* Ever heard of the knife alien?
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#4060609 - 01/07/15 05:27 AM
Re: SpaceX going for a first ever tomorrow
[Re: Peally]
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PV1
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sometime mudslinger
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Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path. Air compression, not friction Wouldn't it be both? I think around mach 1.3 or so friction heating wins over air cooling for air passing over a surface.
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#4060614 - 01/07/15 06:18 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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Paul Rix
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Weaponz248, if you want to learn a little bit about how space flight works (orbital mechanics, spacecraft design considerations, etc etc) in a fun and generally easy to understand format, I high recommend that you should check out Kerbal Space Program. It's surprising how much you can learn from playing it.
Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. Carl Sagan
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#4060993 - 01/08/15 04:50 AM
Re: SpaceX going for a first ever tomorrow
[Re: Ssnake]
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I think around mach 1.3 or so friction heating wins over air cooling for air passing over a surface. That's nice and well but if you're entering the atmosphere from orbital velocity or even higher you're at about Mach 30. By the time you have decelerated to something comparatively benign as Mach 3 the air compression is no longer dominant, but then you have already shed 99% of your kinetic energy. So, for both the longest path of the atmospheric braking trajectory and for the overwhelming amount of kinetic energy decay air friction is a negligible factor in comparison to the heat transfer by air compression. OK. But at the top end, you'll also get a larger fraction of contribution from friction as well, until the air gets thick enough that compression comes in to play - you don't get compression with scattered individual atoms. I wonder how it breaks down; friction might be 10%, maybe 20%? There's a lot of distance in near vacuum before you get to the thicker stuff. I guess the distinction is a function of the mean free path.
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#4061047 - 01/08/15 11:13 AM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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Ssnake
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Feel free to earn yourself a degree in aerospace engineering to answer that question. Seriously - my expertise ends with the fundamental physical factors in play and estimating which one is dominant. From what I understand, the shockwave of the hypervelocity atmospheric entry lets most of the air bypass the spacecraft in some "onion shaped" near vacuum bubble surrounded by oxygen and nitrogen plasma. Only after you reach the denser layers of the atmosphere and by the time that the capsule/spacecraft has slowed down to maybe Mach 6 or 8 you get something resembling a laminary flow that would interact with the capsule body by means of actual air friction. That's still considerable, but at least one order of magnitude less than the heat transfer from air compression for most of the reentry phase. you don't get compression with scattered individual atoms. You do, if you move fast enough (just think of interstellar gas jets that show turbulent behavior; even the densest jets still are what qualifies as a high grade vacuum down here). Or, by the same token, you don't get much friction from scattered, individual atoms. But by definition the atmosphere starts where you have a measurable air pressure. And by that definition you no longer have "scattered individual atoms".
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#4061054 - 01/08/15 11:36 AM
Re: SpaceX going for a first ever tomorrow
[Re: Paul Rix]
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Weaponz248
Hail To The King Baby!!
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Hail To The King Baby!!
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Statesboro GA USA
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Weaponz248, if you want to learn a little bit about how space flight works (orbital mechanics, spacecraft design considerations, etc etc) in a fun and generally easy to understand format, I high recommend that you should check out Kerbal Space Program. It's surprising how much you can learn from playing it. Thanks Paul! I dont think I have played around with that for awhile. Need to check it out again. What DaBBQ said made sense to me, When I think reentry I always think space shuttle which is a glider running on empty. When he said enough fuel it clicked.
XBOX Live Tag/Steam/PSN: Weaponz248
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#4062130 - 01/10/15 03:54 PM
Re: SpaceX going for a first ever tomorrow
[Re: piper]
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Rask
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Well the Dragon Capsule was launched succesfully into orbit and is now on it's way for a rendezvous with the ISS on Monday. The first stage retrival was only a minor success as the stage indeed made it back to the drone ship, but it hit it too hard and was probably destroyed: It was a good try and i bet many things can be learned from the attempt. Well done SpaceX
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