An aerostat is an inexpensive and efficient way to raise a payload in the sky. They are quite insensitive to weather and work equally well in both tropical and arctic climates. Typical payloads are day and night cameras, surveillance radars, VHF and UHF repeaters, TV and radio transmissions.
Filled with helium and fitted with an air ballonet to compensate for changes in temperature and altitude, tethered aerostats can be made in almost any size. Smaller aerostats can be easily packed away and reinflated in only half an hour.
The complete system of the tethered aerostat supplied by Lindstrand Technologies consists of the aerostat, the mooring station, the winch and tether cable. The latter is normally made from Kevlar and carries both the power supply to the aerostat and fibre optics for communications. The cable has a copper outer sheath to protect the aerostat from lightning strikes.