Thursday, April 21, 2011

My first rocketry video - frame by frame analysis



No not the whole thing, which is mostly 5 minutes of a rocket sitting on the ground as I scramble to recover it... but here are a select few frames from my first attempt at onboard rocketry footage. As previously stated, this is a modest offering and much work is needed to ensure future videos have less spin. If wind conditions are better next time, they were dangerously close to 20 mph this time, it would be nice to throw an H motor in there to get some extra altitude for the video. But a few cool things were captured here nevertheless.

This first grab is a fraction of a second after the ejection charge lit (as indicated by the suddenly dark smoke trail.) For the longest time, I just ignored the orange color of the airframe here as perhaps some early debris blocking the camera. But doing a frame-by-frame analysis has indicated something rather different; this is the flash of burning black powder as seen through the translucent airframe! In the next frame, some residual glow can be seen. This is not sunlight streaming through the rocket. It is interesting just how bright this flash must have been.


This next shot is the "dog barf" just after ejection of the recovery system. This is fire retardant newspaper bits used to protect the parachute from ejection gasses and hot particles. Since recovery was late, and the rocket was doing an easy 50 mph at this point, these light bits of paper were sucked away rapidly by the airstream.


Next, the nosecone can be seen flying away in pieces after impacting the rocket and shattering (brittle phenolic.) The waves in the video are the result of the impact.


This frame shows the flightline, including this blogger and other people waiting at the upper left. Also pictured, an essential part of any METRA launch, the food vendor.


And last, just for fun, the moment of impact with flying soil clumps.

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