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Smoke around the launch pad...

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LaunchPad

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I didn't know where else to post this...

Last night when I launched at sunset, I noticed a bunch of thick white smoke that had formed around the launch pad each time.

This is in the grassy soccer field that I use.

So my questions are:
Does this happen every time a rocket is launched and I never saw it before due to the bright sunlight when I did previous launches in the afternoon?

Is this ever a concern? Any risk of fire?
I suppose there is with every launch, but this is not dry brown grass.
 

dhbarr

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Which motor? They all smoke, some more than others.

Low wind, angle of light, yeah; works on clouds, too :)
 

tightwad

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I have noticed smoke hanging in the grass after a launch. Since it is a soccer field there should be no threat from fire as long as the field is green. Always check the grass just in case and pick up all the plastic plugs and spent igniters. Happy flying.
 

Rex R

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probably the moisture in the air reacting with the sulfer in the exhaust to form fog, I've noticed it happen when the air is near the dew point.
Rex
 

LaunchPad

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probably the moisture in the air reacting with the sulfer in the exhaust to form fog, I've noticed it happen when the air is near the dew point.
Rex
Yeah, that could be it since the grass was getting moist with dew.

Thank you Rex.
 

LaunchPad

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I have noticed smoke hanging in the grass after a launch. Since it is a soccer field there should be no threat from fire as long as the field is green. Always check the grass just in case and pick up all the plastic plugs and spent igniters. Happy flying.
I gotta get in the habit of taking a small trash bag with me next time....
Another thing to put in the box.

Do you, or anyone else know, if the plugs are safe to be re-used?
 

Rex R

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the spent igniters are the biggest problem, they don't rust and they have sharp points that can puncture flesh. the plugs present a smaller problem since they don't present as great a hazard if ingested. as long as they hold the igniter in place they can be reused...if you can find them :).
Rex
 

Zeus-cat

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I have reused plugs plenty of times. Please pick up used igniters and starters. I often get on my hands and knees to crawl around and pick up igniters after a club launch. They are just to nasty to leave lying around.
 

rstaff3

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Yeah, that could be it since the grass was getting moist with dew.

Thank you Rex.
That's my theory too. I had seen that several times when the grass was dewy in the first hours of a launch. Kind eerie.
 

MikeyDSlagle

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I've seen it many times launching fireworks. A low smoke mixing in with the grass, never really thought about the "why" of it, was just one of those things. But fog makes sense to me.
 

Buckeye

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You just described one of the coolest things about model rocketry. Now, get yourself some Aerotech White Lightening AP motors and really fill up that soccer field with smoke!
 

bobkrech

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The condition often exists at sunset when there is no wind. The exhaust plume contains very small particles is not dispersed due to the lack of wind so the cloud simply sits around like a fog and is slowly dissipated by diffusion. The low light levels and forward scattering make the effect more apparent near sunset when the plume is between you and the setting sun.
 

Viking

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I love the effect of smoke in the grass.
I don't think there's any trickery, just simply that the smoke is blasted deep into thick grass.
There is usually very little wind at ground level, so after launch the smoke just slowly works it's way back out again.

Some of my video's show the effect very well:
[video=youtube;K4s6gQETLzI]https://www.youtube.com/watch?v=K4s6gQETLzI[/video]
[video=youtube;mMOjY1RHNhI]https://www.youtube.com/watch?v=mMOjY1RHNhI[/video]
 

Micromeister

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probably the moisture in the air reacting with the sulfer in the exhaust to form fog, I've noticed it happen when the air is near the dew point.
Rex
Rex has it exactly!
We see this all the time at our night launches and often with the humidity is High or just after a heavy dew or rain.

I also agree the spent igniter/Starter wires and plastic plugs are of more concern on any athletic field. If uses these fields please be a good steward and police up our area leaving NOTHING but foot prints when your done.
 

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