My question to you is whether individuals have any rights to the airspace above the land they own. Can I, for example, declare the space above my house a no-flight zone (I know that it would be virtually impossible to enforce this), or can this only be done on a national level? –Dawood Salam, Toronto, Ontario

I understand your feelings. You paid good money for that house. Why shouldn’t you be allowed to shoot down bothersome aircraft flying overhead? Well, under the enlightened policy prevailing in the Middle Ages, you would have. For centuries the common-law doctrine was Cujus est solum, ejus est usque ad coelum et ad inferos–literally, “To whomsoever the soil belongs, he owns also to the sky and to the depths.” In other words, you had complete control over everything above and below your property. You want to declare a no-flight zone over your manse? Go right ahead. True, during the Middle Ages there were pretty much no flights, period. But it’s the principle that counts.

This happy state of affairs began to crumble as soon as practical aircraft appeared on the scene. Lobbyists for the infant air-transport industry argued that air travel would be impossible if air carriers had to get permission from the owner of every private property their planes flew over. Possibly also there were whispered promises of frequent flyer miles in exchange for friendly votes. All I know is that the politicians immediately caved. In 1926 the U.S. Congress passed the Air Commerce Act, which declared that the “navigable airspace” of the U.S. was a public highway, open to all citizens. Navigable airspace was defined as the sky above “the minimum safe altitudes of flight” as determined by federal regulators–typically 500 to 1,000 feet above the ground. You see the practical effect of this. One minute you’re lord of all you survey; the next you’re living under the freaking interstate.

Usque ad coelum as a principle of private ownership was formally given the boot by the U.S. Supreme Court in U.S. v. Causby (1946). The court laid down a new rule: you’ve got air rights only insofar as they’re essential to the use and enjoyment of your land. Military aircraft using a nearby airport during World War II had flown over the Causby family chicken farm at an altitude of 83 feet, scaring the chickens and rendering the property unfit for the raising thereof. The court generously ruled that the Causbys had a right to compensation. Big of them, wasn’t it? Bah. Under the previous system Old Man Causby could have taken out a few bombers with his shotgun, and that would have been that.

If it’s of any comfort, usque ad coelum didn’t completely disappear; it was merely transferred to nations. The 1944 Chicago Convention on International Civil Aviation declared that each country had sovereignty over the airspace above its territory. Thus Soviet leaders were within their rights when they ordered the destruction of commercial flight KAL 007 after it strayed over their territory in 1983. Sure, the loss of hundreds of innocent people was unfortunate. But you can be sure the next guys who flew near Russia brought a map.

Even on a national scale usque ad coelum isn’t what it used to be. A 1967 treaty declared that the “exploration and use of outer space, including the moon and other celestial bodies…

shall be the province of all mankind.” Though the frontier of outer space was not defined, some experts argue that it begins about 90 kilometers above the earth’s surface. This is the lowest level at which orbital flight is practical, and it’s also out of range of most nations’ guns.

But some courageous countries are pushing the envelope in this respect. One valuable portion of outer space is the so-called geostationary orbit, located approximately 22,300 miles above the earth’s equator. Satellites in this orbit appear stationary relative to the ground, which is useful for communications, weather surveillance, and other purposes. Recognizing a revenue opportunity when they saw one, eight equatorial countries proclaimed in the Bogota Declaration of 1976 that they owned the portion of the geostationary orbit above their territories. They demanded that any nation wishing to place satellites in said orbit first obtain permission from the country beneath. Since the equatorial nations’ ability to enforce this claim at the time was approximately zilch, the U.S. and other developed countries said: In your dreams. But you wait. If Ecuador ever perfects that 23,000-mile-range surface-to-space missile, I’ll bet negotiations get reopened real quick.

Art accompanying story in printed newspaper (not available in this archive): illustration by Slug Signorino.