Backstory
The G-RAG 3 is a 3-inch diamaeter launch vehicle built to loft the 3rd project of the Goshen Radios Aloft Group (G-RAG). G-RAG was a group of HAM radio and rocketry enthusiasts stared by my dad, Ken Horst, to help develop a real-time GPS telemetry package (see Payload below). It first flew in 2001. The GPS telemetry project was featured in the January/February issue of Sport Rocketry in 2002. It had several other successful flights on J&K motors with a variety of payload configurations. The rocket was retired after losing a fin to a hard landing in the Nevada desert at LDRS 26 (2007).
Payload
We wanted to have real-time GPS telemetry while the rocket was in flight. To do this with off-the-shelf components in 2001 required:
Telemetry Package
- Garmin eTrex GPS
- Serial-data-out cable
- Terminal Node Controller (TNC) for generating packet-radio from the serial data
- External power source
- Yeasu compact 2-meter radio
- Adapter cable from TNC to mic in
Ground Station
- ICOM 2-meter radio
- TNC
- Serial data cable
- Laptop with serial data port
- Terminal session listening to serial data port
It took a few iterations to get this right but, in the end, we were able to get GPS coordinate readings from the rocket to the ground station every second.
Specifications
- Make
- Scratch-built
- Class
- Level 2
- Configuration
- Single motor
- Nose cone
- Shape
- Ogive
- Material
- Plastic
- Airframe
- Diameter
- 75mm
- Material
- Phenolic
- Reinforcement
- Kevlar
- Fiberglass
- Fins
- Count
- 3
- Material
- Laminate
- Airfoil
- Double-wedge
- Reinforcement
- Fiberglass
- Motor Mount
- Diameter
- 54mm
- Centering Rings
- Plywood
- Recovery
- Dual deployment
- Avionics
- Dual altimeter
- Tracking beacon
- GPS telemetry