Tethered balloon
A moored balloon is an inflated fabric structure, often shaped like an airship and usually filled with helium, that is restrained by a cable attached to the ground or a vehicle. Moored balloons differ from airships and free balloons in that it is not free-flying.
Moored balloons are sometimes called aerostats. However, the term aerostat can also be used to refer to all lighter-than-air aircraft. In this broader sense, moored balloons are a type of aerostat.
Moored balloons come in three forms:
- 1) Traditional sausage-shaped (i.e., blimp-shaped) balloons with fins to stabilise them, but relying on helium alone for lift;
- 2) Simple round balloons relying on helium alone, but without stabilisation. These are sometimes are used to carry passengers or support advertisement, like the aerophile balloons;
- 3) Hybrid moored balloons are systems that use both buoyancy and aerodynamic lift.
Applications
Designed by Albert CAQUOT, French engineer, in 1914, the barrage balloons of World War I and World War II were examples of moored balloons. Today, moored balloons are used for lifting, cameras, radio antennas, electro-optical sensors, radio-relay equipment and advertising banners - often for long durations. Moored balloons are also used for position marking and bird control work.
During the 1990 Invasion of Kuwait, the first indication of the Iraqi ground advance was from a radar-equipped moored balloon that detected Iraqi armor and air assets moving south.[1] Surveillance moored balloons were used in the 2004 American occupation of Iraq. They utilized a high-tech optics system to detect and observe enemies from miles away. They have been used to accompany foot patrols in Baghdad.
The United States Geological Survey uses moored balloons to carry equipment to places where conventional aircraft cannot go, such as above an erupting volcano. Moored balloons are ideal as they can easily remain more or less in one place; are less likely to be damaged by volcanic ash and are less expensive to operate than a helicopter.
The Drug Enforcement Administration has contracted with Lockheed Martin to operate a series of radar-equipped moored balloons to detect low-flying aircraft attempting to enter the United States. A total of twelve moored balloons, called Tethered Aerostat Radar System, are positioned approximately 350 miles apart, from California to Florida to Puerto Rico, providing unbroken radar coverage along the entire southern border of the US.[2]
Worldwide Aeros Corp. manufactures a family of moored balloon systems for a variety of uses. Aerophile SA. is one of the world leaders along with Lindstrand Technologies in large tethered gas balloons for passengers.
Moored balloons can be used as temporary transmitters, instead of a radio mast, either by using the mooring rope which holds the balloon as the antenna, or by carrying antennas on the balloon fed by a radio frequency cable contained inside the mooring rope. The advantage of moored balloons is that great antenna heights are easily realizable.
Moored balloons are sometimes used for advertisement, either by lifting up advertisement signs, or by using a balloon with advertisements on it. Often both methods are combined. It is not uncommon to use specially designed balloons. By suspending a light source within the envelope, the balloon can be made to glow at night, drawing attention to its message. Big tethered gas balloons can also lift up 30 passengers to 1,000 feet [3].
See also
- Aerostatics
- Airship
- Balloon (aircraft)
- Barrage balloon
- Buoyancy
- Lighter than air
- Tethered helium balloon
Manufacturers
- SkyDoc Aerostat resources
- Worldwide Aeros Corp - a manufacturer of aerostats
- TCOM - a manufacturer of aerostats
- Top I Vision - video surveillance aerostats
- Aerophile SA- manufacturer of aerostats
- Vigilance Rapid Deployable Aerostat
- Aerostat based communications and surveillance
- SkyDoc Aerostat resources
- Helikites
- Air-Foil Aerostat