Canon EOS 5D Mark II
ƒ/5.6
400 mm
1/3,200
640

Just as she crossed Mach 1, the middle of our airframe burst apart into tiny bits overhead. From the photo analysis below, the reduction coupler began wobbling (despite a solid metal bar running up the middle) before ripping the fiber-glassed midsection apart.

The on-board avionic computer logged data through the supersonic burst, ending in a 100g singularity of shock to the system (chart below).

The upper and lower parts of the rocket fell separately and are largely unharmed, as is the avionics bay and motor. So she should take only a half hour or so to repair. But I did lose both on-board video cameras, the Flip HD did not save its file before losing power, and the cylindrical camera on the parachute line detached as the parachute shredded from supersonic inflation. If anyone finds a black cylinder out there, it might have a killer video. =)

Here is a compilation of the ground video from the pad cams and the flight line where the bottom section came back ballistic.

8 responses to “Supersonic Shatter”

  1. Ready to Launch, with RF tracker in hand… and Pad Cam Two pointing up on the white box:
    IMG_2690

    Pad Cam One (ignition and 0.03 seconds later):
    Screen Shot 2012-10-27 at 4.28.16 PM Screen Shot 2012-10-27 at 4.28.34 PM

    Pad Cam Two
    Screen Shot 2012-10-27 at 2.31.08 PM Screen Shot 2012-10-27 at 2.31.19 PM

    Blastoff with shock diamonds in plume:

    IMG_6982

    Wobble is not good…
    IMG_6987 IMG_6988 IMG_6989

    Boom!
    IMG_6997

    Flight computer Log, with data logging interrupted by the "anomaly" at 3.5 seconds…
    Screen Shot 2012-10-28 at 1.57.42 PM
    Screen Shot 2012-10-28 at 1.59.31 PM

    The red acceleration curve matches the known thrust curve for this motor, with distinctive "dual thrust" zones:
    L640 Thrust Curve

    Upper body with shredded chute and avionics bay:
    IMG_2696

    Lower body as it landed…. Fins and motor are fine, so the repair is easier than it may look. But it was a close call with the vehicles on the flight line….

    IMG_2701

  2. Gee, I just hope that one of these days you guys don’t get your asses blown off!

  3. Possible resonance of that solid metal bar? Maybe you need some damping rather than more structural strength. But my experience with such things is all with subsonic airframes, not supersonic rockets.

  4. so our trip to the moon is off? sorry. ;0}

  5. Great pics Steve! You can see the airframe buckling at the coupler. What was your airframe made of, this is not fiberglass I’m guessing? Also you may need a new chute!


    – Regards

    Gene Engelgau
    KI6IBL, NAR 86770 / TRA 12243 – L3
    fruitychutes.com – Consumer and Aerospace Recovery Solutions
    Like us on Facebook!
    Follow us on Twitter!

  6. It’s a bit of a frankenstein. The parts that survived are the kevlar-socked lower body, the GLR Dynawind upper tube and the fiberglass avionics bay. The part that buckled was the plastic LOC reduction coupler where it inserted into the 4" paper tube that I had wrapped with a fiberglass sock. It still had too much flex.

    Here is a photo of the components with overlay notes (everything right of the center AMW beast).

    It survived one prior flight, with a J1520 that literally knocked over the entire 8-ft. launch rail…

    Intense Rocket Stress Test Astronaut Farmer

    So she could take 30 g’s but not the Max-Q of supersonic flight… =)

Leave a Reply to scleroplex Cancel reply

Your email address will not be published. Required fields are marked *