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Satellite communication is the backbone of wireless communications, and global positioning systems. Satellites in orbit of the planet cover huge footprint territories and make almost instantaneous communication possible.

The key phrase is 'almost instantaneous'. Satellites come in two flavours, geostationary / geosynchronous satellites, and low orbiting satellites.

Geosynchronous satellites are the highest type of satellite, at 22,300 miles or 35,786 km up. At this height it is orbiting at the same speed the earth is rotating, so it can maintain a lock on the same footprint on the surface. This has obvious advantages. Unfortunately, the disadvantage is transmission time. Radio signals take around a quarter of a second to reach and return from the satellite. This delay is very significant if you desire real-time sensory feedback - 60 times a second is preferable, not four.

A low earth orbit satellite on the other hand, orbits much faster than the earth, spinning ahead of it. At an altitude of anywhere between 200 and 2000 miles up, they are used, as they orbit so swiftly, they are in the same place every 90 minutes, and because the nearness to earth greatly shortens the transmission time.

Working in large networks to ensure global coverage, these satellites have transmission delays 100x shorter than geosynchronous satellites. The problem is, low earth orbit is very popular, full of thousands of satellites and parts of exploded satellites. Collisions between pieces are growing ever more frequent.

Enter the stratellites.

If satellites go any lower than low earth orbit, they start to graze the atmosphere. This creates drag, and slows them down. Eventually they slow down too much, and start to plummet, burning up or breaking up in the atmosphere.

To increase transmission speed (decreasing transmission delay) beyond that of low earth orbit, a different paradigm is required. A type of satellite which can survive in high atmosphere.

Sanswire Inc were the first to come up with the Stratellite. As the name suggests, it is a satellite, in the stratosphere. Positioned 13 miles, or 20 kilometres above the surface of the earth, it has the straight up-and-down communications advantages of any other satellite, but reduces transmission times by a factor of nea rly 2000 for geostationary satellites, and 15 for low orbiting satellites.

Using airship technology, a stratellite is above the cloud layers and so can be powered by solar cells and propelled by electric motors which are designed to keep the craft at a single, pre-programmed 3-axis GPS co-ordinate, and check with higher satellites that it stays in that position.

Launching costs are next to nothing, and at nearly 250 feet long, they have enough lift for sophisticated computation equipment - more than most conventional satellites.


Sanswire Inc Stratellites

Wikipedia Stratellites, Friday, 13th July 2007

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