By Taylor Marvin
One of the most interesting areas of speculation about prospective spacefaring humanity is Jon Souza’s so-called Jon’s Law: “Any interesting space drive is a weapon of mass destruction. It only matters how long you want to wait for maximum damage.”
Winchell Chung ably explain the problem, using the example of an impatient science fiction author tempted to replace their fictional spaceship’s slow, boring ion drive with a more powerful — and exciting — fusion drive:
“The good news is that the ship can make it to Mars in twelve days flat. The bad news is that the ship’s exhaust is putting out enough terawatts of energy to cut another ship in two, or make the spaceport look like it was hit by a tactical nuclear weapon.”
This implication is most dangerous for relativistic rockets, whose high speed makes them nearly impossible to intercept and gives sufficient energy to destroy an entire biosphere. To some extent, this rule applies to less fantastically powerful ships possible in a reasonable mid-future setting. Take Kim Stanley Robinson’s recent novel 2312: in this setting, set in the title year, the solar system is extensively colonized. Mars and Venus are both in the process of terraformation, and industrialization and settlement in the outer solar system is widespread. Most intra-system transports are hollowed out asteroids — one described as twenty kilometers long — and spun along their long axis to approximate Earth-normal gravity (the only difference between transports and permanently inhabited habitats is that transports move). These type of transports are extremely ambitious but are readily achievable, and not particularly expensive, for a civilization with self-replicating construction robotics — the only start-up cost is the few initial factory robots, and the asteroid itself. Depending on the propulsion scheme used, these types of transports be able to traverse the inner solar systems in months, and the outer in a few years. Given their enormous interior space, passengers — numbering in the thousands — are awake for the entire trip. Space elevators on Earth and Mars solve the launch costs problem on high gravity worlds.
These transports aren’t particularly ambitious — or fast — by science fiction standards. But even they run into Jon’s Law. If a liners was aimed at a planet, authorities would be very hard pressed to stop it, even with ample warning. Nuclear strikes would just break the transport into lethal debris, still on the same vector as the rogue ship. Other asteroid-defense systems require years of warning, and could be combated by a hostile transport’s defensive systems. If an asteroid-derived transport hurtling along at interplanetary speeds impacted a continent, it could kill millions of people. Chung points out the implications of this destructive potential:
“So one of the logical ramification is that if drives are too powerful, there won’t be any colorful tramp freighters or similar vessels. As a matter of fact, civilian spacecraft will probably by law be required to have a remote control self-destruct device that the orbital patrol can use to eliminate any ship that looks like it is behaving erratically or suspiciously.”
This notion just as applicable to slow, but exceedingly massive, transports.
Robinson avoids this problem entirely. 2312’s space transports don’t appear to be governed by any political authority with its finger safely resting on a megaton self-destruct at all; in fact, in Robinson’s libertarian future specialized liners dedicated to unconventional practices like sensory deprivation or public sex are unremarkable. While these odd-by-modern-standards varieties of transports doesn’t rule out government regulation, 2312 makes it clear that the low cost of establishing liners or stationary habitats makes them available to a bewildering variety of groups unaffiliated with any established polity.
Jon’s Law implies that these transports will be heavily regulated. However, I’m unsure that this type of regulation is even possible in a solar system governed by numerous polities. A single rogue liner represents an existential threat for, say, colonists on Titan. If the Titan government doesn’t have the ability to intensively monitor and remotely self-destruct a Mars-flagged transport subject to Martian regulations, would they ever allow any foreign transports to approach? It would be much safer to only allow transports subject to your own regulations and oversight to come within the danger zone. This threat has teeth because governments could arbitrarily and safely destroy non-hostile transports, but not those on a fast collision course. Each individual government would be better off if they collectively allowed solar system-wide regulated transport, but each also has an incentive to not be the first to make themselves vulnerable. Assuming that separate Sol system polities develop before the advent of routine intra-system transports, this collective action problem could lead to balkanized transport politics that massively restricts trade and immigration.
There are potential regulatory structures that avoid this dynamic. Transports could be operated only by a monopolistic but reliably non-partisan organization, somewhat similar to the Dune universe’s Spacing Guild. Better yet, transports could be required to be governed by AIs, rather than potentially malevolent humans, or required to carry a self-destruct device that could be triggered by any polity, at any time. If intra-system transports are weapons of mass destruction, better to have every finger on the trigger, or none at all.