How I Built My Rastrocam

Note: click on the mini-photos or hypertext links to get the full sized photo with caption.

Rastrocam Exploded view Several people have asked me how I built my Rastrocam (rearward looking Astrocam). I pretty much followed the ideas put forth in Advanced Model Rocketry, Second Edition, compiled by Michael A. Banks. This book is published by Kalmbach Books and includes information about high power rocketry, scale, launch control systems, and many other things, including rocket-borne photography. The picture at left shows my Rastrocam. The picture at right shows an 'exploded view'. As you can see, it's a standard Estes Astrocam, only it's mounted upside down. I cut a piece of body tube from the carrier rocket and topped it with a Maniac nose cone. A length of elastic shock cord ensures it will stay with the camera. I glued a baseJT-55 stage coupler to the nose of the Astrocam to allow it to fit into the rocket's body tube and cut a notch in the coupler to serve as the shutter string holder. Since the regular shutter string is too short, I tied a Shutter
stringlength of shroud line to the Astrocam string. I drilled a small hole in the body tube segment, lined it up with the slot in the base of the camera, and passed the lengthened shutter string through to the other side.

Son of shutter string
For flight, I load the film into the camera following the instructions that came with the Astrocam. I then use electrical tape to seal the film door. I not only run tape along the long edges of the door, I also run a piece of tape around the join line of the camera and the nose cone's body tube. This tape makes sure that the body tube won't twist and bind the shutter string. (I suppose you could glue the body tube to the camera, but then it wouldn't be easy to replace if it gets banged up.) Make sure the string can move freely! A length of tape around the bottom completes the encapsulement of the camera. I attach the Maniac nose cone to the shock cord and put it on top of its body tube to complete the flight configuration. Well, not exactly... I also attach a 12 inch parachute to the shock cord attached to the base of the Rastrocam. Now, it's ready to go.

Rocket/Whoosh Generator Selection

For a carrier rocket, I've used both the Delta II and the Maniac. One of these days, I'll build a Fred Williams Astrocam carrier and try it. I've never gotten a usable photo from a regular Astrocam with the Maniac, since the delays aren't long enough, but a D12-5 and D12-7 have yielded ground shots with the Rastrocam every time. A D12-3 shouldn't be used, unless the rocket will be traveling almost straight up during the coasting period. If it's moving with any sort of groundspeed, you'll get blurred shots. I've gotten good results with B6-2, C6-3, and C6-5 WGs and the Delta II carrier. Don't use an A8-3! You can throw the rocket higher than it'll go on that motor.

Flight Prep

I don't recommend using cellulose insulation as wadding with the Rastrocam, unless you want to see a bunch of white streaks all over your photos... I use the 'toilet paper' type of wadding instead. I then insert the rocket's parachute and pack the Rastrocam's chute on top. Then, making sure that the safety shutter is closed, I cock the camera by pulling the string through the notches in the stage coupler and hold it tight while placing the Rastrocam on the rocket. Once it's seated, I can let go of the string. Then I place it on the launch pad, attach the clips to the ignitor, and open the safety shutter. Now it's ready to fire. Say "cheese!"

Rastrocam launch reports

  • Launch report: 8/27/95
  • Launch report: 4/7/96

  • Ninfinger self-portrait
    Sven Knudson