Spacescape commons: the electromagnetic spectrum and near-earth orbits

Whole Earth, Fall, 1998 by Peter Warshall

The frontier telecommunication commons is still wonderfully ill defined and wireless. Resources are not yet scarce. There are still a multitude of "parking slots" for geostationary satellites, and so far only astronomers have vociferously complained that channels -- to broadcast "are-you-there?" messages to extra-terrestrials -- have become "captured property" of the telecom industry. Every other spectral commoner and cell-phone user appears delighted. So who are we to mention space debris and warn of potential radio-frequency crowding of the spacescape commons, or to mention that babies born since Sputnik have grown up with a night-sky, commons full of blinking and streaking satellites, or now may face a future of many suns (see opposite)?

Starting from the Earth's surface, three volumes of space have become "resources." About twenty kilometers (twelve miles) up, in the HALE (high altitude long endurance) program, dirigibles and pilotless, conventional-looking aircraft will relay data signals in "proto-space." At 350-600 miles, the ionosphere bounces radio and microwaves off its perhaps-limited "wall" space. At 700 to 1,400 kilometers (430 to 870 miles), low earth orbit satellites (LEOs) will vie for parking slots. LEOs are privately owned, cheaper to launch and better suited for video and interactive voice technologies. There are now about 170 in orbit. In ten years, there may be 1,700. Much farther away, at 36,000 kilometers (22,000 miles), but still visible at night, are the geosynchronous orbital satellites (GEOs). These satellites coordinate their speed and movement to the Earth's rotation so that they constantly park over the same spot. To work, they must be at least eighteen kilometers (II.2 miles) apart and on different radio frequencies. if all the parking slots were full, 2,000 GEOs would circle with the Earth, but it is believed that as few as three could serve present needs.

The Spectral Commons

Users of the limited-frequency bands in the microwave and radio ranges must be distinct and non-interfering frequencies for wireless devices to pick them up. These bands are the smallest, highest-value real estate properties on or off the planet. Since the properties are just frequencies in space, they encourage piracy and eavesdropping. Encrypting messages in the spectral commons is like trying to hide out in the terrestrial commons.

The industry, to avoid a commons conflict, has spent big R&D bucks to compress bandwidth, exploit unused bands, and horse-trade or re-assign bands. The Federal Communications Commission, which essentially regulates US interests in the commons, has found an expectant market. It now auctions slots to the highest bidders at billion-dollar prices.

Project West Ford

Project West Ford (1961) was a communications experiment in which small copper filaments or needles (dipoles) were launched into space to reflect radio waves at a frequency of 8,000 megacycles. The experiment primarily tested the usefulness of the dipoles as passive reflectors. The project generated substantial controversy, partly because of scientific objection to the underlying theory and partly because those conducting the experiment did not retrieve the dipoles, thus perhaps interfering with other forms of communications and space activities. The experiment was a failure, as the dipoles did not form a reflective belt; however, 350 million copper filaments continue to orbit Earth. (See The Global Commons., p. 20).