Saturday, April 2, 2011

Aerial Photograph Camera Installation

A lot of people have inquired about the best way to mount a camera in their water rocket. The subject comes up over and over in discussions on the Water Rocket Forum and it seems that there are as many good answers to this question as there are people out there flying cameras on their water rockets.

We've put together a short discussion with an explanation of how we install our cameras on our WRA2 World Altitude Record holding water rockets. Our installation method comes from almost 10 years of experimentation and testing. If you are concerned about the forces that a camera will be subjected to in a water rocket launch, you can be assured that if you follow our methods you will not have any issues.
To begin with, you will need a small and lightweight camera. There are many tiny cameras to choose from and they are reasonably reliable and inexpensive enough that your wife won't make you sleep in the garage if you have to buy a replacement. These cameras produce adequate quality video at a decent frame-rate. It's amazing to see how the video compares to the ones we filmed 5 years ago!

One issue with many of these little cameras is the fact that the time-stamp feature that superimposes the date and time on the bottom of the video is switched on and cannot be disabled. We have a tutorial series on YouTube that explains a cool way to turn them off using the Texas Instruments MSP430 Launchpad Evaluation Kit and some simple soldering skills (don't worry, we walk you through it step-by-step in our video series).

Now, that you have the camera you will want to install it in your rocket. Our method is amazingly simple. We have constructed a section of our rocket which is designed to contain all of the electronics and batteries for the rocket flight. This section which we refer to as the Electronics Bay houses the flight controller and altimeter as well as the deploy electronics and the camera.
As you can probably tell from the image, the Electronics bay is made from a Fluorescent Tube Cover (a plastic tube sold as a protective shield for fluorescent light bulbs) which is wrapped in carbon fiber for strength. You could easily use fiberglass or some other reinforcing material on your own rocket or simply use a hollow bottle segment to house your camera. We use the materials we chose because our rocket can hit the ground at incredible speeds if the parachute does not deploy and we try and protect the electronics as much as we can. Even if our camera and altimeter are destroyed, our technicians can still extract the data from the memory chips and rebuild the video and altimeter graphs if the chips themselves survive the impact.
The way we mount the camera is really simple... we glue it to the inside of the tube. The trick is that we position the camera so that the buttons to control the camera and the USB port are accessible from the opening at the bottom of the tube. We can charge the camera with a laptop while downloading video, etc. and when we are ready to launch, we disconnect from the computer, arm the electrochemical deploy system, start the camera, and attach it to the rocket - then launch.
The only thing left to explain is how the camera can see through the body of the carbon fiber tube. Well, it doesn't record in x-rays so we do the next best thing - we position the camera so the pinhole lens opening lines up with the existing air vent hole that the barometric altimeter we use requires. If you position it carefully, you will be able to look right through a tiny hole like this. It is a lot simpler than trying to make a clear "window" in the side of the rocket (we know, because our older rocket cameras had huge lenses that needed a wide opening to see out of).

There you have it, we hope that you find this little discussion useful and inspiring.

Thanks for visiting!