Canon EOS 5D Mark II
ƒ/6.3
100 mm
1/2,500
320

My son’s scratch built “Epic” rocket had another epic flight.

Three fin-tip motors light on the pad, and then a central Skidmark is lit by the on-board HCX flight computer. You can see the various igniter wires here, and the Contour HD cam near the nose.

Here is the video compilation of this launch, one of the most complicated of the weekend. (frame grabs)

It also has an RF-tracking beacon, which proved to be quite helpful as I was visually tracking a different rocket on the return that had crossed paths with ours.

Below are the rest of the photo sequence, each 0.25 seconds apart.

10 responses to “Epic Cluster Rocket Launch”

  1. jurvetson Avatar
    jurvetson

    Three Aerotech G40 White Lighting motors light at the pad
    IMG_3112

    then the central skid lights (main photo above). Then she arcs over into the wind…
    IMG_3114

    the polecat striped effect we were hoping for…
    IMG_3115

    cool sparky chunks of titanium sponge showering over the flight line:
    IMG_3117

    Reply
  2. BWJones Avatar
    BWJones

    Epic indeed! Where do you go to light these rockets?

    Reply
  3. filmisdead Avatar
    filmisdead

    Wow! Very cool

    Reply
  4. jurvetson Avatar
    jurvetson

    thanks!
    [http://www.flickr.com/photos/78637244@N00] – This was at a Dairy Farm south of Fresno (i.e., far, far away). For the really big stuff, we go to the Black Rock Desert, Nevada.

    Reply
  5. flytrue2 Avatar
    flytrue2

    I’m actually a bit surprised at the stability of the fin mounted design. Anytime you increase the moment-arm you increase the likelihood that any asymmetry in thrust will result in a rocket that cartwheels skyward around the cg. Nicely done.

    Reply
  6. jurvetson Avatar
    jurvetson

    We have done that too, but mainly from insufficient nose weight, or too much motor hanging out the back… =)

    From earlier flight experience with this airframe, she tends to fly stable with the center motor lit, regardless of how many fin motors are going.

    I just downloaded the flight file. Here is the data from launch to apogee:
    Screen shot 2011-05-28 at 3.50.22 PM
    on the far right, you can see the accelerometer and baro sensor spikes for the explosive deployment of the nose cone parachute, and then the yank of the chute filling with air.

    And a zoom in to the first 3.5 seconds:
    Screen shot 2011-05-28 at 3.51.08 PM
    Looking at the red acceleration curve, you can see the three G40 motors alone for the first 0.4 seconds. The computer-ignited central I140 motor kicks in around 0.5 seconds. The thrust of the G40s rolls off around 1.5 seconds. And the central I motor finishes at 3.25 seconds (as should be expected, since it has a 2.75 second burn, starting 0.5 seconds in).

    Reply
  7. flytrue2 Avatar
    flytrue2

    I never know what to expect when I visit but it’s always interesting. Thanks for posting the data!

    Reply
  8. solerena Avatar
    solerena

    Shiny:)

    Reply
  9. TomiTapio Avatar
    TomiTapio

    Sparklies! Powered by Vampire Dust? j/k

    Reply
  10. Arthur Sixtenson Avatar
    Arthur Sixtenson

    Great work, it could not been much better than that! Think you maybe like my pictures, so take a look! 🙂

    Reply

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