The DoongaraPlus Balloon Cut-Down Device is a small self-contained thermal line cutter that utilizes redundant burn-wires to sever synthetic line commonly used on high-altitude weather balloon flights. The device has an on-board barometric pressure sensor, timer, and high-altitude GPS to determine when to sever the line based on user-programmable settings.
Why Fly a DoongaraPlus Balloon Cut-Down Device
- Terminate your high-altitude balloon flight before it drifts too far away to ensure recovery
- Utilize tandem ballooning to float at altitude for extended periods of time with a latex weather balloon
- Drop a device or ballast during the flight
- Cut away balloon remnants after a balloon burst to prevent tangling
- Log where your balloon went during its flight
Features of the DoongaraPlus Balloon Cut-Down Device
User feedback and suggestions from the Doongara have lead to the creation of the DoongaraPlus. Notable changes include:
- The DoongaraPlus can utilize GPS-based geo-fencing to determine when to sever the line. Now you can fly high-altitude balloons without having to worry about them drifting off, making recovery hard or impossible.
- The DoongaraPlus can utilize GPS-based altitude to determine when to sever the line. It is no longer necessary to convert from altitude to pressure when programming.
- The DoongaraPlus is programmed through a text file on a micro-SD card. There is no longer any need to download and install USB drivers.
- The DoongaraPlus has extensive data logging capabilities. It logs a comprehensive comma-separated file at 1Hz. This file contains which trigger caused the line to be severed, barometric pressure, GPS position, and GPS altitude. A KML file is also logged at 1/4Hz for quick post-flight analysis in Google Earth. The KML file includes a marker for when the device severed the line.
- The DoongaraPlus features a power-on button and audio status indicator. These allow the device to be completely configured, rigged, and placed into its foam enclosure the night before launch. Then, during the inflation process, the DoongaraPlus can be quickly turned on and confirmed to be operating correctly. This ensures the fastest and safest balloon launch possible.
DoongaraPlus User-Programmable Triggers
Any combination of the triggers is permitted. When multiple triggers are enabled, the first trigger condition to be satisfied severs the line.
- GPS Altitude Trigger—severs the line above a user-specified altitude.
- Geo-fence Trigger—severs the line when it moves outside of a user-defined area.
- Mission Elapsed Time Trigger—severs the line after a user-specified amount of time elapses.
- Minimum Atmospheric Pressure Trigger—severs the line once a user-specified atmospheric pressure level is achieved during balloon ascent.
- Rapid Descent Trigger—severs the line when a rapid and sustained pressure increase is sensed (like after balloon burst).