Project:
A video transmitting high power model rocket.
Designer(s):
N8UDK
Description:
Every summer my friends and I travel to the tip of the upper peninsula of Michigan for a week of camping, hiking, and construction of some really cool tech projects. Rockets have always been a source of enjoyment for me and then somewhere around 1992 I got the ATV "bite". Now I know there has been many people who have installed ATV transmitters in rockets but I really wanted to combine my two favorite hobbies rocketry and ATV.
I should mention that I belong to a national organization called "Tripoli" which is a great group of people with rockets on the brain. They host exciting launches all over the country and publish a excellent magazine. The term "High Power Rocketry" mainly refers rockets that have motors which are much more powerful than the kind you normally purchase from you local hobby store. Rocket motors with more muscle allow us to achieve higher altitudes and loft heavy payloads.
The ATV rocket is actually a pretty simple project. Obviously one could make it much more complicated but I decided not to add any bells and whistles like telemetry overlay or remote control options. I actually launched two rockets with the payload seen in figure 1. The first launch was in the summer of 1992 with a small H-120 motor. The rocket had a mirror on the outside which was attached at a 45 degree angle. The camera looked through a hole in the rocket, into the mirror which showed a view of the ground during lift off. Once the ejection charge fired (to deploy the parachutes), the rocket became two pieces (main rocket body with mirror and payload section with the ATV equipment), so the camera (not looking through the mirror any more) pointed at the horizon as it drifted slowly down on a parachute. The second launch occurred in the summer of 1993. It was constructed with speed and altitude in mind. It has no external mirror on the outside to slow it down. The camera pointed through a small plastic covered hole in the rocket at a 40 degree angle. The motor I used for this rocket was a J250 and man did it fly!
Some Technical Information:
The payload consists of a one watt PC Electronics transmitter (439.25 MHz out) attached to a vertical dipole antenna. The vertical dipole (with some big nulls) wasn't the best antenna for the application but it was convenient. The camera was a black and white Chinon which you can see in the bottom of the payload module in figure 1. The camera and transmitter's power came from ten AA alkaline batteries. For reception I used a custom built crossed dipole antenna with ground plane which attached to a P.C. Electronics down converter. The output of the down converter (on channel 3) feed my VCR and TV.
Hardware:
Hardware Sources:
Conclusion:
Both rockets flew very well and I should stress I took all the rocket related safety issues very seriously. The mirror on the 1993 rocket did cause some instability during flight. Rocket 1994 flight was very impressive. My computer models for it calculated a maximum height of 12,000 feet with the maximum speed of 900 MPH. I believe it was quite accurate. The video in both flights was very good. At any time during the flights P2 was the worst picture quality and P5 was seen for a large portion of the time the rockets were in the air.
- Chris Oesterling N8UDK
Fig 1.0 - "ATV Rocket 92/93 payload"
Fig 2.0 - "ATV Rocket 93 on the pad in Houghton, Michigan"
Fig 3.0 - "ATV Rocket 93 liftoff"
