Satellites and Geography

The world's network of satellites and earth stations constitute a critical, and often overlooked, element in the global telecommunications infrastructure. While most treatments of this topic typically depict it in technologically deterministic, apolitical terms, satellites are deeply embedded in terrestrial political relations.

Satellites in orbit appear in a variety of sizes and degrees of technological sophistication. Large satellites capable of handling international traffic sit 35,700 km (22,300 miles) high in geostationary orbits, which are by far the most valuable orbital slots because only in that narrow sliver of space do satellites and Earth travel at the same speed relative to each other, making the satellite a stable target for signals transmitted upward from earth stations. Because such orbital arcs are a scarce resource, their distribution is strictly controlled through international organizations. The cost of launching satellites and the fuel needed to maintain them in their proper orbit are also constraints to their economic viability. Satellites typically have a 10-yr. (year) life span, primarily because they exhaust their available fuel, necessitating their eventual replacement by a new, frequently much improved, generation. From its vantage point, a broad-beam geostationary satellite can transmit to (i.e., leave a “footprint” over) roughly 40% of Earth's surface, creating instantaneous time-space convergence, so that only three or four are sufficient to provide global coverage. Because the cost of satellite transmission is not related to distance, it is commercially competitive in rural or low-density areas (e.g., remote islands), where the high marginal costs dissuade other types of providers, particularly fiber optics providers.

The terrestrial counterpart of the satellite is the earth station. There are tens of millions of earth stations located worldwide, ranging in size from 0.5 to 30 m (meters). The vast majority, however, can only receive information, not transmit it (i.e., downlink only). When microwave signals are sent over great lengths and become broadly diffused, earth stations require large, powerful antennas to receive them. The distribution of the world's 483 publicly owned earth stations designed for international traffic in 2004 reveals that they are concentrated in the largest and wealthiest countries, particularly the United States, which, with 70, has vastly more than any other state.