How to become a space pirate
As humans continue exploring further out into space, through both government organizations like NASA and up and coming private space enterprises like SpaceX and Blue Origin, we're going to need a lot more laws to govern space.
The US just made it legal for Americans to mine resources from asteroids, but space, and especially business in space, is largely unregulated right now - which makes it surprisingly easy for someone to become a space pirate.
Space law basics
Could the first person who steps on Mars declare themselves supreme ruler of the planet? Would you have to obey a speed limit in your moon rover? If someone wanted to settle on Mars permanently and build a Martian castle (Elon Musk maybe?), would he be able to buy a plot of land?
Well, according to Article I of the United Nation's Outer Space Treaty, one of the most important parts of the laws that govern space, every celestial body in space, including Mars, falls under international law:
Outer space, including the moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.
And so, as of now, no state, person, or company can lay claim to any land that's not on Earth:
Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.
BUT! People, governments, and private corporations still own, say, their living quarters, spaceships and rovers that they send to another planet.
Space piracy
So essentially the universe beyond Earth counts as international waters. But crafts out in space still belong to their owners.
This is exactly what leaves ships in international waters open to piracy: when a crew commandeers a ship and steals its cargo.
Turns out if you tried the same move in space (by raiding a spacecraft instead of a ship) that would technically make you a "space pirate."
Currently, the International Space Station (ISS) belongs to Europe, the United States, Russia, Canada, and Japan, and the Mars rover Curiosity belongs to the US. So, if a crew ever boarded the ISS without permission from the countries that own it, it'd be space piracy.
And in "The Martian," Mars-stranded NASA astronaut Marc Watney gives a great (and hilarious) example of how international law would manifest on Mars. When he is inside a NASA-owned Mars habitat, US law applies. But as soon as he steps outside onto Martian soil, he's in international waters.
At one point, Watney needs to use a NASA spacecraft called Ares 4. NASA hasn't explicitly given him permission to climb aboard, and according to the UN Outer Space Treaty, you can't lay claim to anything in space - so he must "commandeer" Ares 4, an action that will technically make him a pirate under international law.
"After I board Ares 4, before talking to NASA, I will take control of a craft in international waters without permission," Watney says in the book. "That makes me a pirate! A space pirate!"
Writing new laws is already a complicated process, but writing them for an inhospitable, alien world like Mars may be even harder. How much freedom can someone expect to have on a planet with no breathable air or protection from radiation?
Compliance with certain rules might deprive people of what we on Earth consider basic freedoms (think about having to stay indoors during a dust storm or only having a certain amount of oxygen per day to use to explore the planet), but it could mean the difference between life or death.
Some groups, like those at the annual International Extraterrestrial Liberty Conference, are already trying to figure out how we'll govern space if humans attempt to settle somewhere beyond Earth.