Balloons. Blimps. Lighter-Than-Air aircrafts. Aerostats. There are many classifications of airborne devices that have occupied the skies for a number of years. An article from the Journal of Aircraft titled “Analysis and Design of Robust Helium Aerostats” provides useful background information describing the physical properties of aerostats.
The technology of an aerostat is not new. However, with increased use through the U.S. military and defense-related organizations, the term has been receiving more attention. Essentially, an aerostat is a system of technologies that work together. Below is a detailed description of how this system works. Researchers Jonathan Miller and Meyer Nahon from McGill University in Quebec, Canada explain:
“A typical tethered aerostat system consists of a fabric envelope to contain the lifting gas, one or more tethers to moor the balloon to the ground, a flying harness to distribute the tether load over the aerostat, load patches to attach the flying harness to the envelope, and occasionally, a pressure-regulation system known as a ballonet.” (p. 1147)
To “moor” simply means to fasten or secure. The term ‘tether’ is a synonym for rope or a cord that ties two objects together. Aerostats are usually either blimp-shaped or sphere-shaped. In the case of the JLENS technology, their aerostats are in the shape of blimps. Even though tethered aerostats are fixed by a secure cable, they still require the use of helium gas to retain buoyancy in the air.
Knowing the inner-workings of any type of technology is useful even if one is not an expert in the field of science, engineering or computing. Providing a well-rounded technical and social evaluation of aerostats in general helps to better conceptualize the specific technology of JLENS.
Miller, Jonathan I. and Meyer Nahon. “Analysis and Design of Robust Helium Aerostats”, Journal of Aircraft, Vol. 44, No.5 (2007), pp.1447-1458 http://arc.aiaa.org/doi/abs/10.2514/1.25627?journalCode=ja&&