Lightweight avionics platform to access atmospheric environmental science

There is a region of the atmosphere between approximately 10-40 km above the Earth’s surface that is inaccessible to most winged aircraft and that rockets visit only fleetingly, but where small unmanned balloons are increasingly being used to carry lightweight (<5 Kg) scientific payloads. A major disadvantage of using these inexpensive ‘weather’ balloons is that researchers often have to develop telemetry and support avionics in addition to the core experiment. The aim of this thesis project was to significantly reduce this challenge by developing a Lightweight Avionics Platform (LAP) that would be able to support a wide range of experiments by providing data from a suite of sensors and a GPS receiver, together with an Iridium satellite link for communicating with internet enabled ground stations. The LAP also provides non-volatile storage for the sensor, GPS and experiment generated data. The LAP design is based on a low power consumption microcomputer that is compatible with the Arduino Integrated Development Environment (IDE) and its associated open-source communication and sensor interface libraries. Modular systems architecture was employed as an aid to rapid hardware development. A major design goal was to allow researchers to interface their experiments without affecting the integrity of the LAP’s embedded operating software. A dedicated Science Interface Port (SIP) is provided for this purpose that allows experiments to be powered and data exchanged, via a single electrically robust connector. This part of the project was completed with the construction and testing of a flight-capable LAP that weighs less than 0.2 Kg. In order to ascertain the reliability of the above platform when subjected to the low temperatures and pressures expected during stratospheric flight, the project included the development of an environmental test chamber and associated monitoring/logging system. A unique feature of this low cost chamber is that it is both portable and transparent to satellite communications’ signals. Finally, design details for a proposed atmospheric dust sampling experiment are provided as an example LAP application.