Saturday, March 14, 2015

Holtville March 2015 launch report

It was another beautiful day in the desert although a tad windier than we're used to. I've been wanting to get my drone in the sky to shoot some liftoffs and that worked our rather dandily:
For some reason I forgot to set the controller to GPS mode so I was struggling to keep the thing where I wanted on the first few clips.  The 480 fps liftoff of Mark Treseder's Skidmark is quite nice although I think that slow mo is generally wasted from the air. In the future I'll probably switch to 720p 120 fps mode as a nice balance between spatial and temporal resolution.  Also, for the first time, I used Pocket Wizards to remote fire my DSLR while I flew the drone.  Shit's gettin' complicated!  Also Google rocks overall but I've officially switched from PicasaWeb to Flickr for my image posts from now on.
     I had only two flights but was pleased with both.  The first was the trusty 4" fiberglass Madcow Nike Smoke on an AT K1103X Propellant X reload for the 54/1706 casing.  I should note that AT included the wrong seal disk O-ring but Paul Snow saved me with a spare from his archive.  Thanks, Paul!  Thermite seemed in order so I ran with 2g which was a bit higher than the 1g/1000 N•s guideline.  Ignition was instantaneous according to Darrel who pushed the button for me (these two frames are 0.5s apart):
Darrel and I trekked my standard mile to retrieve the thing in a depression.  Even with line-of-sight on descent I think I would have lost the rocket without the CTI tracker:

Upon recovery I noticed that all of the nozzle's divergent section and most of the throat were missing:

Lucky for me no other issues arose as a result of this blow out.  I'm not sure if that was a faulty nozzle or perhaps the 4,500˚F Thermite caused a thermal gradient in the glass-phenolic nozzle and it shattered on pressure up.  Dunno.   The CTI 217H170 Blue Streak was next in the similarly trusty DS Lite and it landed in site of the launch pad:

1 comment:

oddmanrockets said...

Thumbs up Greg nice video