The thickness of glaciers in High-Mountain Asia (HMA) is critical in determining when the ice reserve will be lost as these glaciers thin but is remarkably poorly known because very few measurements have been made. Through a series of ground-based and airborne field tests, we have adapted a low-frequency ice-penetrating radar developed originally for Antarctic over-snow surveys, for deployment as a helicopter-borne system to increase the number of measurements. The manoeuvrability provided by helicopters and the ability of our system to detect glacier beds through thick, dirty, temperate ice makes it well suited to increase greatly the sample of measurements available for calibrating ice thickness models on the regional and global scale. The Bedmap Himalayas radar-survey system can reduce the uncertainty in present-day ice volumes and therefore in projections of when HMA's river catchments will lose this hydrological buffer against drought.

Aviation is an advanced technology, constantly pursuing higher performance, and backed by painstaking research into new materials and techniques. The target of “performance” has changed with the period, but the extent to which energy can be provided for propulsion has always been rated of major importance. Since propulsive energy is stored on board in a fuel medium, the more obvious criteria for the fuel are the energy density (based on mass and/or volume) and the proportion of this energy usable within the propulsion system. At the same time, the fuel must respond safely to reasonable handling procedures. The more subtle requirements to emerge over recent years include those of a minimum potential for pollutant formation and, in the case of very high speed flight, a maximum capacity for heat absorption.