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Re-entry plasma visualization Issue Tools
issueid=601 10-12-2010 08:31 AM
Addon Developer
Re-entry plasma visualization

I think the formula that Orbiter uses for calculating when the re-entry plasma is wrong as if you fly a standard shuttle entry profile you never get to see it at all.

According to Urwumpe here: http://www.orbiter-forum.com/showpos...postcount=1099
this seems to be due to that Orbiter uses free stream air flow for the calculations when it should be really local air flow.

Any chance this could be changed? Seems a bit odd not seeing any plasma at all during entry.
Issue Details
Issue Type Feedback
Project ORBITER: 2010-P1 and newer
Status Open
Priority 1 - Highest
Regarding Version 100830 (2010-P1)
Regarding Version (none)
Users who agree 9
Users who disagree 0
Assigned Users (none)
Tags Graphics, Physics, Vessel Related

10-13-2010 03:20 PM
Crazy dude with a rocket
 
its not that the formula itself is wrong (Martin is usually thorough about his math) - but it is that the formula, although correct, is being fed inaccurate values...

based on what Urwumpe said, seems Orbiter is using the "raw" air flow parameters to infer for plasma, which doesn't account for how said flow reacts around the shape of the shuttle...

i guessa quick fix would be to start the plasma effect a little earlier... no need to overcompicate things... the overall dynamic is correct, just needs a little tuning, i guess


BTW, if the plasma "ball" turns white, that means you're dead
Reply
10-15-2010 09:00 AM
Donator
 
Quote:
Originally Posted by Moach
  i guessa quick fix would be to start the plasma effect a little earlier... no need to overcompicate things... the overall dynamic is correct, just needs a little tuning, i guess
Is it possible for the "normal user" to modify those parameters to get the plasma effect with the Shuttle? if yes, how?
Thanks
Reply
10-17-2010 06:13 AM
Addon Developer
 
Quote:
Originally Posted by Wolf
 Is it possible for the "normal user" to modify those parameters to get the plasma effect with the Shuttle? if yes, how?
Thanks
Another related question is how Orbiter defines the color of the entry pstream and flame?

I want to edit it match the real entry colors as seen in this photo of Endeavour doing a roll reversal during entry of STS-130: http://twitpic.com/14of2q
Reply
01-17-2012 11:00 PM
Orbinaut
 
Is it also possible to be able to see your own re-entry flames? I know AMSO did it, but I think they just made the flames larger.
Reply
01-26-2012 10:09 PM
Spring of Life!
 
It is possible for this to be addressed with a graphics client? It has been brought up in the D3D11 thread, and made a new thread on it here: http://www.orbiter-forum.com/showthread.php?t=26178,

or is this something that can only really be solved in a future update to Orbiter?
Reply
01-22-2013 03:46 PM
Addon Developer
 
Here's some information I have found on the subject:

Checking with the STS-107 Entry Flightdeck video, the first report of plasma visible from the forward windows was at EI+00:30, with it becoming visible to the camera at EI+02:10.

According to Revision 15 of the STS-107 Accident Investigation Summary Timeline posted by NASA on March 17 2003, start of peak heating was at EI+05:54 at an altitude of 72,914.4 m and at a ground relative speed of Mach 24.12.

According to Bill Anders (Apollo 8 LMP) in the Discovery Channel documentary "When We Left Earth, part 2 'Landing the Eagle/The Explorers'", the color of the entry plasma starts out pink then transitions to red, orange and finally yellow.
Reply
01-23-2013 03:03 AM
Dread Lord of the Idiots
 
thats "peak heating".
Reply
10-31-2015 11:17 AM
Addon Developer
 
I have been testing the recent modifications relating to this issue (beta revisions 38 and 39) and while it is going in the right direction, it's still not there. It still appears a bit late. I have attached a pre-entry scenario with the default Atlantis. In this scenario the plasma starts at EI (122.2 km)+03:50 minutes which is about 90 seconds to late. Also the custom plasma column particle stream added with AddReentryStream should be moved behind the the pink non-custom particle stream and be made yellow.

In the beta thread, I linked this video of the STS-135 entry to show-case how a real object undergoing re-entry looks like.

http://www.youtube.com/watch?v=2XZgu7FStbw

Code:
BEGIN_DESC
Orbiter saved state at T = 81296
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 51983.8932113816
END_ENVIRONMENT

BEGIN_FOCUS
  Ship STS-101
END_FOCUS

BEGIN_CAMERA
  TARGET STS-101
  MODE Extern
  POS 4.000000 25.741918 59.192695
  TRACKMODE GlobalFrame
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Map
  REF Earth
  TARGET Cape Canaveral
  POS 0.00 0.00
  DISP 62639
END_MFD

BEGIN_MFD Right
  TYPE Surface
  SPDMODE 1
END_MFD

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS 5670547.463 -3626624.966 -75199.827
  RVEL -3895.5815 -6153.2077 2491.4860
  AROT 110.000 -10.000 80.000
  AFCMODE 7
  PRPLEVEL 0:1.000000
  IDS 0:588 10 1:586 10 2:584 10 3:582 10 4:580 10
  NAVFREQ 0 0
  XPDR 466
END
STS-101:Atlantis
  STATUS Orbiting Earth
  RPOS 4576753.945 1063803.965 -4563306.134
  RVEL 5127.6469 1450.0435 5711.1152
  AROT 63.266 -73.744 27.123
  VROT -0.0414 0.0000 -0.0000
  PRPLEVEL 0:0.896310
  NAVFREQ 0 0
  CONFIGURATION 3
  GEAR 0 0.0000
  ARM_STATUS 0.5000 0.0000 0.0000 0.5000 0.5000 0.5000
  SAT_OFS_X 0.000000
  SAT_OFS_Y 0.000000
  SAT_OFS_Z 0.000000
  CARGO_STATIC_MESH Carina_cradle
  CARGO_STATIC_OFS 0.000000 -1.650000 0.050000
  MET 0.000 0.000 0.000 0.000
  ASCENTAP 0 0 350000 1.5708 0.00000 0.00000
END
Carina:Carina
  STATUS Orbiting Earth
  RPOS 4576753.945 1063803.965 -4563306.134
  RVEL 5127.6469 1450.0435 5711.1152
  AROT 63.266 -73.744 27.123
  VROT -0.0414 0.0000 -0.0000
  ATTACHED 0:0,STS-101
  AFCMODE 7
  NAVFREQ 0 0
END
END_SHIPS
Reply
11-01-2015 08:52 PM
Cold fusion devices since 1948
 
Quote:
Originally Posted by DaveS
 I have been testing the recent modifications relating to this issue (beta revisions 38 and 39) and while it is going in the right direction, it's still not there. It still appears a bit late. I have attached a pre-entry scenario with the default Atlantis. In this scenario the plasma starts at EI (122.2 km)+03:50 minutes which is about 90 seconds to late. Also the custom plasma column particle stream added with AddReentryStream should be moved behind the the pink non-custom particle stream and be made yellow.

In the beta thread, I linked this video of the STS-135 entry to show-case how a real object undergoing re-entry looks like.

http://www.youtube.com/watch?v=2XZgu7FStbw

Code:
BEGIN_DESC
Orbiter saved state at T = 81296
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 51983.8932113816
END_ENVIRONMENT

BEGIN_FOCUS
  Ship STS-101
END_FOCUS

BEGIN_CAMERA
  TARGET STS-101
  MODE Extern
  POS 4.000000 25.741918 59.192695
  TRACKMODE GlobalFrame
  FOV 50.00
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_MFD Left
  TYPE Map
  REF Earth
  TARGET Cape Canaveral
  POS 0.00 0.00
  DISP 62639
END_MFD

BEGIN_MFD Right
  TYPE Surface
  SPDMODE 1
END_MFD

BEGIN_SHIPS
ISS:ProjectAlpha_ISS
  STATUS Orbiting Earth
  RPOS 5670547.463 -3626624.966 -75199.827
  RVEL -3895.5815 -6153.2077 2491.4860
  AROT 110.000 -10.000 80.000
  AFCMODE 7
  PRPLEVEL 0:1.000000
  IDS 0:588 10 1:586 10 2:584 10 3:582 10 4:580 10
  NAVFREQ 0 0
  XPDR 466
END
STS-101:Atlantis
  STATUS Orbiting Earth
  RPOS 4576753.945 1063803.965 -4563306.134
  RVEL 5127.6469 1450.0435 5711.1152
  AROT 63.266 -73.744 27.123
  VROT -0.0414 0.0000 -0.0000
  PRPLEVEL 0:0.896310
  NAVFREQ 0 0
  CONFIGURATION 3
  GEAR 0 0.0000
  ARM_STATUS 0.5000 0.0000 0.0000 0.5000 0.5000 0.5000
  SAT_OFS_X 0.000000
  SAT_OFS_Y 0.000000
  SAT_OFS_Z 0.000000
  CARGO_STATIC_MESH Carina_cradle
  CARGO_STATIC_OFS 0.000000 -1.650000 0.050000
  MET 0.000 0.000 0.000 0.000
  ASCENTAP 0 0 350000 1.5708 0.00000 0.00000
END
Carina:Carina
  STATUS Orbiting Earth
  RPOS 4576753.945 1063803.965 -4563306.134
  RVEL 5127.6469 1450.0435 5711.1152
  AROT 63.266 -73.744 27.123
  VROT -0.0414 0.0000 -0.0000
  ATTACHED 0:0,STS-101
  AFCMODE 7
  NAVFREQ 0 0
END
END_SHIPS
I tried your scenario, but I don't see a pink stream, I see only a gray stream.

I've also tried your scenario in Orbiter with D3D9 but shuttle produces a CTD, I will report it.
Reply
11-01-2015 10:19 PM
Addon Developer
 
Quote:
Originally Posted by Matias Saibene
 I tried your scenario, but I don't see a pink stream, I see only a gray stream
You can actually see a hint of it. The gray plasma column actually obscures the pink plasma surrounding the vehicle. That's why it needs to be moved back.
Reply
08-31-2016 04:05 PM
Addon Developer
 
Is there any way to manually set the trigger points for the plasma stream?
Reply
09-26-2016 05:53 PM
Addon Developer
 
Here's a nice video of the STS-93 entry plasma trail as seen from the ground as Columbia was heading for her landing at KSC: http://www.youtube.com/watch?v=OUH-v5QPxko
Reply
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