What laws do astronauts follow in space? What happens if an astronaut smokes pot, commits murder, or breaks other criminal laws while in space? —Fred Van Hecke

Back in the 70s, advance reports that Skylab’s crew was to be supplied with small rations of wine inspired so much public outrage that NASA instituted a strict ban on in-flight alcohol consumption. Any astronaut caught smoking pot, then, might well be summarily forced out the nearest hatch as a matter of policy. As for other forms of space murder: not a likely occurrence just yet, but if commercial off-earth travel does become routine, eventually human nature will take its course and some serious crime will occur outside of terrestrial jurisdiction. Ideally by then there’ll be working guidelines to cover such eventualities; thus far, though, the field of criminal law hasn’t left our planet’s atmosphere.

It’s not like authorities have been reluctant to export earth-style legal thinking into the cosmos. Barely a year after the 1957 launch of Sputnik, the U.N. established the Committee on the Peaceful Uses of Outer Space, and a 1967 treaty set forth a kind of extraterrestrial constitution, establishing that space and the celestial bodies therein are intended for the use and mutual benefit of all humankind and may not become the property of any nation.

Various other international treaties (establishing things like an obligation to rescue astronauts and liability for damage caused by space objects) and nonbinding agreements followed; the 1996 Declaration on International Cooperation reaffirmed that space is the “province of all mankind.” On the other hand, the 1979 Moon Agreement, mandating that lunar resources be shared equally, hasn’t attracted any major signatories—as I suggested a few years back, nobody’s eager to sign away the quadrillions of dollars in moon minerals that may await.

When all astronauts were either military officers or civilians directly under the authority of a government space agency, none of this mattered much. But then Dennis Tito’s 2001 visit to the International Space Station kicked off the era of space tourism; if private citizens increasingly become spacefarers, complex legal matters will have to get hashed out, presumably in accordance with existing principles of international law. Let’s look at a few space-crime hypotheticals:

Bob and Alice are aboard a NASA spacecraft. Bob eats the last freeze-dried mac-and-cheese meal; Alice cracks his skull with a wrench. Under the principle of territorial jurisdiction, Alice could be tried under U.S. law, because the craft is U.S. government property. For a murder aboard the International Space Station, jointly owned by several nations, jurisdiction would fall to whichever one controlled the segment of the station where the murder occurred.

If Bob and Alice are private citizens on a private spacecraft, things get a little messier. If the craft is registered in the United States, then presumably U.S. law would apply, as it does aboard U.S. ships at sea. But if the spacecraft isn’t registered anywhere, a sovereign state might invoke the principle of nationality, which permits an exercise of jurisdiction over its citizens even when they’re abroad. This is the concept under which U.S. nationals are still required to pay the IRS tax on income earned while living abroad, forbidden to engage in sex tourism with minors, etc.

Let’s say a space-based terrorist cell whose members have renounced all earthly citizenship plot to steer an asteroid into Chicago; to defend itself, the United States could go after them under the protective principle of international law.

If those same terrorists hijack a private spacecraft in orbit, any state might try to justify intervention under the universality approach, based in the longstanding notion that certain serious crimes — piracy being the oldest example — are such a general scourge that nations have a collective interest in combating them.

Finally, and most expansively, a country could attempt to defend its own space-traveling citizens by simply claiming jurisdiction over criminal acts committed against them by any other persons anywhere, under what’s called (somewhat opaquely) the principle of passive personality.

These scenarios deal with serious crimes—terrorism, piracy, murder. The same principles could also apply to lesser infractions, though it’s hard to say if anyone would bother enforcing them. If a French pickpocket relieves a Spanish moon-tourist of his wallet, neither country could claim territorial jurisdiction or a need to protect itself. Petty larceny clearly doesn’t meet the universality standard, and it’s easy to imagine each country concluding it’s not worth invoking nationality or passive personality for such a low-level crime.

And there’s the rub. In space as on earth, law is one thing, enforcement a whole ‘nother. Will a force of space cops be dispatched to the scene of the crime? A criminal court convened in orbit? Will criminals be extradited back to the surface, or will private prison companies expand their reach into the greater galaxy? Stephen Hawking, for one, continues to insist that humanity’s survival will depend on our abandoning the earth. I’m not sold, but if he’s right, no matter how tempting it may be to leave them behind, we’ll have to take at least a few of the lawyers with us. —Cecil Adams