Exploring Earth's atmosphere using high altitude unmanned instrument platforms
ASTRA investigates new technologies for making low cost observations of the physical parameters of the atmosphere. We develop and test platforms capable of delivering scientific instruments to altitudes ranging from the planetary boundary layer (hundreds of metres) to the upper stratosphere (up to 50km).
The use of fleets of light, unmanned aircraft, makes extensive studies more affordable, even when payloads need to be delivered to extreme altitudes. It also enables applications where the deployment of manned aircraft is impractical, such as when observations need to be made in highly polluted environments (e.g., volcanic ash clouds) or extreme weather conditions.
The challenges of developing such system are of a highly multi-disciplinary nature, involving:
Aircraft design: the aircraft have to be able to operate in the harsh, low pressure, low density environment of the upper stratosphere, as well as in the dense and turbulent lower troposphere. Additionally, weight and power requirements of all on-board systems have to be minimized. The need to keep weight and cost to a minimum demands novel manufacturing technologies too.
Flight physics: efficient sampling of atmospheric parameters requires very careful design of the trajectories and flight control algorithms of the aircraft. This is an especially pressing requirement if unpowered gliders are used.
Software systems engineering: the real-time, often computationally intensive ground-based processing of large amounts of data collected by the sensors on board the aircraft is made especially challenging by the difficulties of data download from very high altitude platforms with low powered transmitters.