Solar Flare Takes a Strange Turn in Florida Skies

At yesterday's ROCK launch, something rather odd happened which I caught in a series of photographs.

A two-stage Estes Solar Flare made the first flight of the day.

The launch looked good.

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The first part of the flight was nominal with the rocket making a slight arc as it soared skyward.

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Just as the first-stage motor burned out, the rocket took a sharp turn.

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It headed off to the left.

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Then second stage fired.

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And the two stages shot off in opposite directions.

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The upper-stage did a little skywriting before straightening out and heading for the horizon.

Additional photos of the above flight and the ROCK launch are in the RocketReviews.com Photo Album.

-- Roger

Did you recover the upper stage ? If so, was there any damage or weaked areas ? That's really a crazy turn considering the timing. Maybe a hung booster?

CG/CP issue at booster burnout?

Bounced off invisible cloaked spacecraft?

Seriously, that's pretty odd. Awesome pictures, BTW. What camera?

To me it doesn't look like the usual CG/CP stuff; it made a sharp turn that had to be a reaction to some sort of event. My money is on the booster getting a little hung up on one side during staging. The separation push might have been asymetrical causing the rocket to swing around. I saw something similar though less extreme with my Corona (Fliskits) when the booster popped off. Rocket did a sharp 30 degree turn from boost angle. The next flight was more extreme and was documented somewhere here. Booster didn't come off at all and did a Krushnick effect.

I've got a solar flare waiting in my pile. I'll be on alert when I build it to make sure it can separate cleanly.

Meanwhile, here's the scene in Signs where there is a report of a bird striking an invisible spacecraft.:

[YOUTUBE]PeTi9g1NqyY[/YOUTUBE]

Marc

Flight reviews at EMRR indicate off-kilter staging is not unheard-of with the Solar Flare.

https://www.rocketreviews.com/solar-flare---estes.html

Tarasdad said:

CG/CP issue at booster burnout?

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Marc_G said:

To me it doesn't look like the usual CG/CP stuff; it made a sharp turn that had to be a reaction to some sort of event. My money is on the booster getting a little hung up on one side during staging. The separation push might have been asymetrical causing the rocket to swing around. I saw something similar though less extreme with my Corona (Fliskits) when the booster popped off. Rocket did a sharp 30 degree turn from boost angle

Click to expand...

I don't think the problem is at booster burn-out. The third and fourth photos show the booster motor still burning, and the fourth is a nice side-on shot showing that the booster stage is still on straight. It's interesting that the Corona had the same problem because it has a similar fin configuration to the Solar Flare, a ring fin around narrow span diamond-shaped fins. And the Solar Flare has additional small fins in the middle of the body. If the problem were to do with separation, you'd expect it to be more common with multi-stage rockets regardless of fin layout.

I wonder what effect high speed airflow has on that fin configuration? Suppose higher speed causes the ring plus small fins to become less efficient, perhaps due to increased turbulence around the roots of the support fin making the ring less efficient? If the model is optimised to have the CP 1-2 diameters behind the CG at launch, and if the CP then moves further forward than the CG as the booster burns fuel and the rocket gains speed, this could make it become unstable. It might be worth building a single stage model with the same fin dimensions as the full stack Solar Flare, with the CG arranged by suitable nose weight to be in the same place as a fully loaded two-stager. This would simulate the flight of the first stage while eliminating any possible effect from separation.

The booster keeps burning after the staging event, though. The staging pulse of pressure happens when the dome shaped expanding front of burning BP breaks through the top, but there's still residual stuff on the sides of the engine burning when it happens. This would explain the smoke, IMHO.

MEanwhile I think it's a great idea to build a single stager model as Adrian describes.

Was this the Solar Flare's first flight, or has it flown successfully before?

That is too bad,did you get it all back? Excellent camera work by the way.

1) Check booster motor to make sure it was a "-0" and not a "-2" or a "-3".

2) Check vent hole to see if there was excessive flame effect. If the upper stage started to fire but the booster was too tight, it could have stayed attached too long and exhaust coming out the vent hole would have destabilized the rocket. Once the stages come apart, the upper stage can then stabilize and fly in a straight line.

3) Check booster motor for nozzle damage which could cause vectored thrust. If a chunk of nozzle broke away during boost, there would be an obvious unusual looking spot and it would be covered with normal exhaust crud. If the nozzle gets chipped upon landing, the chipped area would not be covered in exhaust crud.

I don't recall any staging problems with mine. What motors did you use?
https://www.rocketryforum.com/showthread.php?2392-Estes-Solar-Flare&p=43743#post43743

Thanks for the comments, all. It wasn't my rocket and I'm not sure who the flyer was. I think the rocket was recovered.

My first thought was that a non-booster motor was used in the first stage, but you can see from the photographs that there's no tracking smoke before the staging event. The upper stage acted as if it was unstable until the motor had burned a little then it took off straight. The day was unusual in that there was little to no wind. So, perhaps, the rocket was only marginally stable but stayed straight until something caused it to deviate just before staging. I don't know.

The photos were taken with my Casio EX-F1 camera. Normally, I have a hard time following a rocket in flight with the camera because it has a small electronic viewfinder and it's hard to quickly adjust the zoom level. I think I just got lucky this time keeping the rocket in the frame.

That wasn't the only weird thing that happened Saturday. I don't have any photos, but we watched one rocket descend normally under parachute until it was about 50 feet above the ground when, suddenly, the parachute just closed up and the rocket fell the rest of the way to the ground.

-- Roger

The sudden parachute fold-up was probably due to a brief wind shear -- a "reverse thermal" where wind suddenly gusts down instead of up.

The same thing COULD have something to do with the Solar Flare going cockeyed at staging.

Very strange indeed! Similar to the Mars Lander that went wonky at the MMMSC launch last Saturday. This ML has flown a few times and I watched it fly two weeks ago.

https://www.youtube.com/watch?v=AtgfbotvSY0

JStarStar said:

The sudden parachute fold-up was probably due to a brief wind shear -- a "reverse thermal" where wind suddenly gusts down instead of up.

The same thing COULD have something to do with the Solar Flare going cockeyed at staging.

Click to expand...

We have seen some changes in the wind around that altitude at our launch site. It seems that the trees block the wind at lower altitudes, so there's a sudden change above a certain height. But, I'd never seen anything as dramatic as that Solar Flare's left turn.

We had a "micro-burst" type of event at the site a couple of years ago. It was a day with little wind and, all of sudden, tents and other things where flying in the air. A similar, but less dramatic event happened more recently. We saw grass and other debris swirling around a corner of the field. Then, the vortex moved across our launch area and I recall watching it carry some flight cards at least 100 feet into the air.

Fortunately, those events are pretty rare.

-- Roger

Funny, in my club's last launch the same thing happened, only it was a dust devil in the middle of black rock . I'd never seen a dust devil before, I didn't think it would be nearly that big.

I've seen vortexes like that in the sports fields at my school, all though they were pretty small.
It sure would be interesting f one of those just happened to pass through the smoke trail from a white lightning or black jack motor. I'll bet it would make an awesome picture if the rocket was still in the frame!