Stratospheric Payload Test Bed Development, 16-9297

Principal Investigators
Le Moey Wiebush
Allan B. Black
Kurt A. Franke

Inclusive Dates: 02/04/02 - 05/04/03

Background - Stratospheric platforms provide advantages over satellites. These advantages include lower price, station-keeping ability at lower altitudes, and rapid deployment. The current multi-division SwRI Buoyant Stratospheric Vehicle (BSV) program needs a payload flight test method that is fast, low cost, and allows easy payload recovery. This research was funded to produce a prototype test-bed vehicle.

Approach - The test-bed system consists of a weather balloon and a small autonomous glider. The two-meter wingspan glider is lifted by the balloon and released at a selected altitude. The glider navigates to a recovery location using a sensor suite consisting of a GPS receiver, an air-speed sensor, and a single-axis rate-gyro. Using a simple radio command link, the glider flight computer sends status information to the ground operator and accepts special commands such as changing the destination coordinates. The ground-control system is hosted on a notebook computer and features an interactive map display. A typical joystick control box for remote-controlled model airplanes is used for landing the glider.

Accomplishments -

• Sensors, computers, and actuators are integrated into the prototype flight vehicle.
• A successful release latch was developed and tested.
• Numerous low-altitude flights have provided experience in testing the initial flight control programs for controlling the glider.
• A wind-compensating algorithm for heading control was developed and tested.
• Ground-based software for monitoring and issuing commands to the glider was written and flight tested.
• Using a dynamic pressure sensor and single-axis rate-gyro, glider stability and control feedback was implemented.
• Several mid-altitude flights were performed, including flights from 10,000, 15,000, 20,000, and 30,000 feet.
• A demonstration payload consisting of a 1.3 Mega-pixel digital camera was flown on several low-altitude flights. Images were stored on-board and recovered from the glider.
• Limited environmental chamber (temperature and altitude) tests of critical parts were performed.
• Low-level test flights of a new and larger (2.5 meter wingspan) glider were performed.
• Work has begun on a glider body featuring insulation and heat-management capabilities.

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