OHM Dragon DLL

[OrbitHangar]

Author: brianj

An integrated .dll version of Donamy's SpaceX "Dragon" spacecraft.
Automatic chute deployment, sun-tracking solar panels, docking strobe, etc. Automated De-orbit burn and Re-entry attitude/splashdown targeting. Payload attachment by editing scenario "ATTACHED" vessel parameter, or in-sim by entering payload vessel name.
Also includes RecoveryVessel as splashdown target. Historical scenarios for CRS-6 launch, ISS approach, de-orbit, are included in the "Dragon1" folder on the Orbiter launchpad selection. Installation and operation notes in Doc/Dragon1/dragon1_readme.

 

UPDATE 160623: Fixed CTD when attached to parent vessel.

 

REQUIREMENTS

Included scenarios require:

"Falcon9R" add-on
http: //www.orbithangar.com/searchid.php?ID=6593

"Canada rm2v4" add-on
http: //www.orbithangar.com/searchid.php?ID=6883

BIG THANKS to Don!



DOWNLOAD

 

[romanasul]

Excellent, I can't wait to test it.

 

[Donamy]

...and an even bigger thanks to Brian.

 

[Wolf]

Great addon! automatic reentry was great fun: splashed down just a few hundred meters from recovery vessel. Only one thing is that the reentry plasma and heating effect on the dragon heatshield do not show...

Got an issue with the launch scenario: F9 pitches down too much right after liftoff, levels off at around 4 Km altitude and flies back down to earth... :huh:

 

[BrianJ]

Great addon! automatic reentry was great fun: splashed down just a few hundred meters from recovery vessel. Only one thing is that the reentry plasma and heating effect on the dragon heatshield do not show...

Got an issue with the launch scenario: F9 pitches down too much right after liftoff, levels off at around 4 Km altitude and flies back down to earth... :huh:

Hi,
thanks for the kind words

You should be getting some particle/plasma trails during the CRS-6 reentry scenario - do you have a non-standard Earth atmosphere enabled? Are you using Orbiter build 100830?

Could you run the CRS-6 launch scenario until it goes wrong and then post your orbiter.log here? Thanks.

Do you have any "attachment manager" type modules activated?
Check the mass of the Falcon9R before the launch scenario liftoff (F4->Object Info) - it should be 510552kg.

Cheers,
Brian

 

[barrygolden]

Once again Brian has really brought this to life. From a guy who has hands on dragon with space X, domany and brianj has made this and out standing addon, so enjoy it and thanks to both of you.

 

[Wolf]

Hi,
thanks for the kind words

You should be getting some particle/plasma trails during the CRS-6 reentry scenario - do you have a non-standard Earth atmosphere enabled? Are you using Orbiter build 100830?

Could you run the CRS-6 launch scenario until it goes wrong and then post your orbiter.log here? Thanks.

Do you have any "attachment manager" type modules activated?
Check the mass of the Falcon9R before the launch scenario liftoff (F4->Object Info) - it should be 510552kg.

Cheers,
Brian

Thanks for the quick reply Brian.

I did some checks and this is what I got:

1) Launch: you were right!! it was the damn Attachment Manager module that interferes with F9 and screws up the launch. Deactivated and I had a perfect nominal launch with Stage1 Landing on the spot :thumbup:

2) Reentry: I only get some White trail that starts showing around 60 Km alt. Then, as the dragon reaches approximately 50 Km the textures change into the "reentry burnt" ones BUT there is no sign of orange plasma around the vessel nor any heating effect of any sort on the capsule-heatshield (just the textures change at 50 Km)

I do run Orbiter build 100830 ( D3D9 rev.14) with the following athmospheric effect addons:
- EEEo2006
- Environment_060522
- cloudmicrotex

here are two shots of reentry, one at 60 Km and the other at 50 Km ALT

View attachment 13752


View attachment 13753

 

[Wolf]

Once again Brian has really brought this to life. From a guy who has hands on dragon with space X, domany and brianj has made this and out standing addon, so enjoy it and thanks to both of you.

Couldn't agree more!!!

 

[IronRain]

Thank you both very much! I loved it already, and this adds even more realism.
Thank again!

 

[BrianJ]

1) Launch: you were right!! it was the damn Attachment Manager module that interferes with F9 and screws up the launch. Deactivated and I had a perfect nominal launch with Stage1 Landing on the spot

2) Reentry: I only get some White trail that starts showing around 60 Km alt. Then, as the dragon reaches approximately 50 Km the textures change into the "reentry burnt" ones BUT there is no sign of orange plasma around the vessel nor any heating effect of any sort on the capsule-heatshield (just the textures change at 50 Km)

I do run Orbiter build 100830 ( D3D9 rev.14) with the following athmospheric effect addons:
- EEEo2006
- Environment_060522
- cloudmicrotex

Hi Wolf,
glad the launch works OK. The Falcon9R simply follows the gravity-turn after the initial pitch-over, so if it is carrying more mass than it "thinks" it is, you get a launch "anomaly"! I should really put some kind of sanity-check in the code for that. Also, it brought to light a bug with the Falcon9R add-payload-mass-in-sim function which I have now fixed.

I'd hazard a guess that either D3D9, EEEo2006 or Environment_060522 are the cause of the lack of reentry trails on your set-up. The reentry trails are sparse anyway, on my default Orbiter 100830 installation, unless you get an off-nominal reentry or carry more than 1600kg payload - then you get proper fireworks. This may be partly down to the fact I had to mess with Orbiter's aerodynamics functions quite a bit to get the desired "Apollo" style behaviour for the capsule (about which I might post later).

I can always crank up the reentry trails if people think there should be more Easy enough to do.

@Barry & IronRain
Hey guys, hope you have some fun with it. Gotta say Thanks again to Don for allowing me to mess with his meshes!

Cheers,
Brian

 

[Wolf]

I can always crank up the reentry trails if people think there should be more Easy enough to do.
Brian

Thanks a lot for the answers Brian, It would be nice to know if other users can see more reentry "fireworks" then I do. Should not they be happythen maybe you could think about giving it more plasma.
One thing though remains, and maybe it is once again due to my atmospheric addons: the capsule heatshield does not show any heating effects as it encounters denser atmosphere during reentry (no red - orange or yellow glow). It just suddenly changes from brand new white to a dark grey burnt effect as it passes through 50 Km ALT.
Can anybody else confirm this?

A BIG thank to you and Donamy for this beauty!
Really looking forward to run some SpaceX F9 missions to the ISS AtoZ: what a wonderful couple of realistic addons!

 

[DaveS]

I'd hazard a guess that either D3D9, EEEo2006 or Environment_060522 are the cause of the lack of reentry trails on your set-up. The reentry trails are sparse anyway, on my default Orbiter 100830 installation, unless you get an off-nominal reentry or carry more than 1600kg payload - then you get proper fireworks. This may be partly down to the fact I had to mess with Orbiter's aerodynamics functions quite a bit to get the desired "Apollo" style behaviour for the capsule (about which I might post later).

This is an actual known fault with Orbiter's entry visual generation calculation: http://www.orbiter-forum.com/project.php?issueid=601

 

[Wolf]

This is an actual known fault with Orbiter's entry visual generation calculation: http://www.orbiter-forum.com/project.php?issueid=601

I guess this is the same reason why the Shuttle Fleet does not generate any plasma trails at all during a nominal reentry (which is really a pity)..

 

[Donamy]

The heatshield never had a glow to it. It would have to be added.

 

[Wolf]

The heatshield never had a glow to it. It would have to be added.

You mean the Dragon1 heatshield Don?

 

[BrianJ]

You mean the Dragon1 heatshield Don?

Yeah. No glow at the moment. I'll see if it can be done reasonably easily. Maybe for the next update.

In the meantime, attached to this post is a .zip with replacement .dll's that will generate more reentry trails. Unzip into your Orbiter folder as usual, overwrite the old .dll's. If folks prefer these ones, I'll update the OH file.

 

[boogabooga]

The method that Orbiter uses to determine re-entry plasma is simply not correct for that purpose, and on both ends. It underestimates the appearance of plasma at high velocity and low density, and it over-estimates at high density an relatively low velocity.

What it does is calculate density times velocity cubed and displays the plasma when that value exceeds a threshold that can be set for the vessel in the API.

My impression is that this is being used based on looking at some model for atmospheric heating on the vessel. However, for displaying plasma, the way to think about it is how the vessel is heating the air. This is getting to the concept of blunt body re-entry. Why to the capsules re-enter blunt end first, and not pointy end first- the answer is so that the kinetic energy of the craft can go more to heating the air and not heating the vessel. The plasma that one sees on re-entry is the nitrogen and oxygen, etc. molecules themselves being ionized when the air is heated above a certain temperature, probably with some ionized species from the spacecraft body being mixed in.

A blunt body well above supersonic speed has what is called a bow shockwave. That is, the air is being massively compressed before it even reaches the spacecraft. This compression heats the air itself. Re-entry heating is often attributed to "friction," but really compression is a major factor.

The good news is that it would not take complex math to get a suitable reentry plasma behaviour to please the community. The compression heating is largely determined by the Mach number. I would say, IF there is any detectable atmosphere (say, whatever the static pressure is at 100km on earth) AND the Mach number is above 12 (ish), THEN render plasma TRUE. Else, FALSE.

Working with the current orbiter "rho vee cubed" system, what the developer could do (I think) is check for this pressure/Mach condition and set the rho vee cubed threshold WAY low when it is true and set the threshold WAY high when it is false to sort of over-ride the system. That is, if you change the threshold in flight.

 

[Donamy]

Yes, my original addon, didn't have a glowing heatshield mesh.

 

[boogabooga]

Wolf, I think you are thinking about Glider's Dragon from this:

[ame="http://www.orbithangar.com/searchid.php?ID=5442"]SpaceX launch vehicles and Dragon[/ame]

That one does have a glowing heatshield.

 

[BrianJ]

Working with the current orbiter "rho vee cubed" system, what the developer could do (I think) is check for this pressure/Mach condition and set the rho vee cubed threshold WAY low when it is true and set the threshold WAY high when it is false to sort of over-ride the system. That is, if you change the threshold in flight.

Probably easier just to use AddParticleStream() instead of AddReentryStream(), then you can control the level directly.