Disaster can happen at any moment in space exploration. “A good rule for rocket experimenters to follow is this: always assume that it will explode,” the editors of the journal Astronautics wrote in 1937, and nothing has changed: This August, SpaceX’s rocket blew up on a test flight.

But exploding in space isn’t the worst thing that could happen. You could suffocate or be stranded on the moon—a slow death. You could be a child born in space, deformed by space radiation and microgravity during fetal development, then raised apart from the rest of humanity. You could go mad from the social isolation of space.

As Defense Advanced Research Projects Agency’s 100-Year Starship Mission, Inspiration Mars Foundation, Planetary Resources, Deep Space Industries, and many other private and public space programs make their grand plans, we need to think carefully about not only the physical risks of space exploration but also legal and ethical risks.

For instance, Mars One is still sorting through thousands of applications to be the first residents on Mars—and reality television show stars—with the first batch scheduled to blast off in 2023. But is it even ethical to recruit astronauts for a one-way trip—essentially a suicide mission? Or does that exploit a vulnerable population that has an overdeveloped sense of adventure or other psychological conditions?

As Facebook, OkCupid, and other technology companies recently discovered, their experiments could be seen as “human subjects research” in some key respects. Likewise, the space industry could find itself subject to this ethically strict framework and others that haven’t been discussed much. Being an adventurer or scientist doesn’t exempt you from labor laws, for instance. Herewith is a sort of Astronaut Bioethics 101. (Elon Musk, take notes.)

Lifeboat ethics in space

Let’s look at one plausible scenario to start. In 2025, suppose you are the captain of a spaceship bringing four crewmembers to the red planet. Previous spacecraft were already sent to build a basic habitat and food supply, and now your ship is only five days away from landing and joining a few others already there. But something has gone terribly wrong: Micrometeorites have pierced the hull and caused a slow leak. Calculations show there will not be enough oxygen for all four crew members to survive. Unless one person stops breathing immediately, all four will asphyxiate before landing. If you wait even one day before sacrificing a crew member, then at most two members could survive.

As the captain of the ship, what should you do? If you volunteer to die, who will then pilot the ship in the final, treacherous landing maneuvers? Should the doctor be killed, risking the future lives of the colonists? Or the engineer, tasked with keeping the habitations running? What about the scientist who hopes to make fundamental discoveries, perhaps even alien life? Should you make sure at least one male and one female survive, so future procreation is possible—and does it have to be a couple? Or should you just draw straws?

This kind of scenario could become all too real in the near future. Humans, for the first time, are beginning to extend space flight to destinations in which return to Earth is possible only in time frames of months to years, if ever. In those travels, we encounter truly novel circumstances—destinations more impossible to return from than even for Christopher Columbus sailing off to the New World.

The habitation modules of Mars One will be a fragile oasis of water and oxygen on an otherwise desolate and profoundly inhospitable Martian soil, where temperatures average around minus 67 degrees Fahrenheit. Those astronauts will be subject to the whims of solar and dust storms, meteorite strikes, physical injury, possible alien contamination, and the other barely glimpsed hazards of Martian living.

This is to say, many things can go wrong on Mars. Given the dangers and severely limited resources, including medical, what should astronauts do if they need to choose between the lives of their fellow astronauts, a so-called lifeboat decision? This is a question best answered in advanced and not during the panic of the moment, when our judgment may be compromised.

Crisis planning is neither unreasonable nor unprecedented in space or anywhere else. In the summer of 1969, Neil Armstrong and Buzz Aldrin returned to Earth as heroes, as the first men to ever walk on the moon. But what if they never made it back? President Nixon had a speech ready for that disaster, written by William Safire: “Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace. … For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind.”

Sex and kids

One crisis the all-male crews of the Apollo program never had to worry about was the possibility of a pregnancy in space. But that won’t hold true for would-be mixed crews headed to Mars, especially missions planning colonization.

Space agencies haven’t had to deal with it much so far, though astronauts think about sex, and it occasionally gets them in trouble, too. Given plans now for long missions, we need to confront the issue as well as the usual things related to it, such as babies.

If we send heterosexual astronauts, of different sexes and of reproductive age, on extended space missions, then the possibility of pregnancy looms. To ward that off, could it be ethical to demand sterilization for any potentially fertile astronauts in a mixed-sex crew? Radiation exposure may eventually take care of the issue by causing infertility, but some pregnancies could happen before infertility occurs. Is conception even possible in the zero-gravity of space, or in the low-gravity, high-radiation habitats on Mars? If so, would a fetus develop normally?

We don’t know, since it would seem patently unethical to even conduct these sorts of experiments today in space or anywhere else, at least with human subjects. Again, the physical and psychological dangers of procreating and living outside of Earth can seem inhumane, especially for involuntary subjects (the children). Yet many plans for space exploration already take it as a foregone conclusion that humans will reproduce in space. For some, it’s a crucial part of the business plan, as in the case of Mars One’s goal of moving toward a “permanent human settlement.”

Inspiration Mars Foundation, a competitor of Mars One, has an interesting way to account for the pesky human sex-drive on long missions: The company is recruiting older married couples to ensure stability in the relationship and to avoid the ethical problems with having babies in space. It recognizes that the problems of sex begin with interpersonal dynamics among the crew.

But why married couples? They’re infamous for squabbling in confined spaces for months on end, and more than half of marriages in the United States end in divorce. Is that really better than sending only men, or only women, or unmarried crew members into space? Other related ethical issues with sex include the possibility of rape: Should abortions be allowed in outer space—and how should crimes be handled? (We’ll return to this in a moment.)

Psychology and privacy

It will also be critical to account for mental health and resiliency on long missions. An astronaut who suffers a major depressive episode or a psychotic break while stuck in space won’t have access to medical and psychological interventions that we do here, for instance.

Governmental astronauts are carefully screened with psychological tests, since conditions such as suicidal ideation and sociopathy might cause trouble in space. If an AI is part of the crew, we might need to also test the computers, lest it get inspired by HAL and think the puny humans are getting in the way—after all, it might decide that the mission is too important to let you people jeopardize it.

But NASA’s studies of psychological problems during missions on the International Space Station, or even on pseudo-Mars habitats in the Arctic, do not begin to match the reality of the problems posed by a six-month or longer mission to Mars. The best-case scenario for those astronauts is still a constantly stressful existence within a tiny community of fellow settlers.

Major psychological challenges that are impossible to fully prepare for on Earth would include unprecedented social isolation. Real-time interaction with friends and family back on Earth will be impossible: The shortest delay for sending transmissions would be approximately 10 minutes. To make things worse, for the duration of their lives, the Mars One participants would know direct interaction only with their fellow settlers who, even if all goes well, would increase from only three people in the first two years to 23 others after 10 years.

There’s also the related problem of confinement. While some pioneers on Earth may cheerfully choose to be isolated for months to trek through unexplored reaches of the polar regions or the deep ocean, that won’t be the case for children of Mars One colonists. They’ll be stuck on Mars. Primate studies indicate that being raised in captivity has harmful effects on the development of young apes, including experiencing abnormally high fear and a reduced desire for exploration—exactly the wrong traits for success as colonists on a hostile planet. Would this spell disaster for the long-term survival of the colony, as well as for the well-being of the children themselves?

To make things worse, the astronauts would lack physical privacy for the rest of their lives in a tiny habitat on Mars. (And then there’s the whole “reality TV” angle. Would the children experience a real-life version of The Truman Show?) But we won’t even be able to carry out research to get an idea of what that would mean: It’s difficult to imagine that any institutional research board would allow anyone to risk that, and so far there’s no clear and present danger—such as a killer asteroid that may wipe out humanity—that justifies such an extreme experiment.

Laws and discrimination

To mitigate some of these problems, Mars One and others are conducting physical and psychological screening of astronauts. But in most contexts, it’s illegal to reject job candidates because they are disabled or have predispositions toward some health conditions. We can perhaps understand why a paraplegic person wouldn’t be an ideal astronaut, but what about a fully healthy person whose family has a history of cancer or depression?

As a Netherlands-based mission, Mars One would be subject to at least Dutch anti-discrimination laws, which are similar to the Americans With Disabilities Act and Genetic Information Nondiscrimination Act in the United States. These laws typically bar discriminatory treatment for persons with certain physical and psychological conditions, such as a genetic disposition for Alzheimer’s disease.

The loophole here is that countries with anti-discrimination laws routinely include a “bona fide occupational qualification” exception that can justify discrimination that would otherwise be unlawful. But the BFOQ must be defensible. For example, until last year, U.S. policy presumed that women are unfit for combat roles in the military. But the reasons behind the discrimination against women in the military turned out to be weak. That kind of conversation for space missions should be made more explicit and transparent, if they want exemption from the democratic value of nondiscrimination. And the results may have implications for other BFOQs on Earth, so we need to think carefully here.

Back to the issue of sex and reproduction: Could Inspiration Mars Foundation’s astronaut-selection strategy be illegal? Labor laws prohibit recruiting only older married heterosexual couples in just about every known case, as they bar discrimination on the basis of age, gender, sexual orientation, and other differences.

One possible objection is that many or all of these private space programs are building an all-volunteer cadre of unpaid adventurers, so they aren’t employers in the usual sense and therefore shouldn’t be subject to labor laws. But labor laws also protect the unpaid, such as interns and volunteers, and presumptively cover even volunteer astronauts. It’s at least worth investigating.

You might argue that the astronaut or the workplace needs to be on Earth for labor laws to apply. After all, U.S. federal laws and regulations, such as from the Occupational Safety and Health Administration, don’t reach into outer space, even if they bind NASA workers while on the ground. But NASA has its own health standards that it follows; it’s not as if all bets are off in space. Indeed, many nations have already agreed to be bound by the Outer Space Treaty and the Moon Agreement, though neither regulates the behavior of individual astronauts, only the signatory states.

These are conversations we can have right now on Earth. But legal disputes and crimes could crop up while in space, giving us good reason to export law enforcement, courts, and other state institutions off-planet. Death is inescapable before too long, and each one needs to be investigated to rule out homicide. But this is still a challenge in Antarctica and other remote parts of our home planet. Asteroid mining, Mars colonies, and other such plans already raise the issue of how property rights should be handled in space. But how do we decide which laws and institutions are needed on Mars in the first place, and who gets to decide?

Other bioethics puzzles

What about human enhancements? Artificial reproductive technologies (such as in vitro fertilization and even artificial wombs) and pre-implantation genetic testing could have a role in addressing some of the worries mentioned above. Others may be very useful for purposes beyond reproduction: a greater ability to breathe at lower partial pressures, to resist space radiation, to survive with little sleep or food, or to think faster and more clearly in stressful situations. But human enhancements raise all sorts of ethical worries in normal Earth contexts, such as safety to the human subject, fairness, reversibility, and unintended effects.

Bioethics frameworks can help us here, as we start to hit upon questions about informed consent and acceptable risk—a subject deserving of its own article. But let’s note that bioethics doesn’t need to be concerned only with human life: There are things inside us that aren’t human.

It turns out that only 1 in 10 cells in our body is actually Homo sapiens genetically, and the rest make up the flora known as a microbiome inside every one of us. The microbiome is increasingly understood to have crucial effects on our health, yet the effect of long-term spaceflight on it is largely unknown. Could zero-gravity or increased radiation environment cause unpredictable changes in our gut bacteria, perhaps even ones resulting in lethal disease? Even a pandemic in the colony?

Speaking of nonhuman life, one of the most exciting aspects of space exploration—and a main focus of NASA—is the search for alien life. One of the activities Martian colonists will likely engage in is the search for Martian microbes, in the hope that we will find a second source of life in the universe. Of course, astrophysicists such as Paul Davies remind us that life on Earth might have begun with microbes that hitched a ride from Mars. But could they hitch a ride back on astronauts? If the search for alien life on Mars fails, we will surely one day search for it in the oceans of Europa or Ganymede, or the petrochemical seas of Titan and so on, until we find that we are not alone in the universe.

In the event of alien contamination, even if a remote possibility, we need to think about the quarantine of astronauts. Under what circumstances, if any, should we deny living astronauts the opportunity to return to Earth? NASA’s Office of Planetary Protection has protocols in place, but private businesses, such as Mars One, aren’t legally obligated to follow them. Suppose a sick astronaut on a private spaceflight wants to return to Earth: Who would have the authority to forcibly stop her, even if we could? For that matter, how can we know for certain whether an astronaut is infected before it’s too late?

Look before we take another giant leap

Those bioethical challenges are just the beginning. Space agencies have long been focused on the health and safety of their astronauts themselves, and experts are looking at the ethics of finding extraterrestrial life or astrobiology. But the possibility of long missions means that other social dynamics and future generations become relevant now.

Eventually, every colony will want its independence, history suggests. For Martian settlers, that independence may exist de facto from the very start, so perhaps all bets really are off where authorities can’t reach. Thus, with the possibility of space exploration, we have a clean slate in front of us to reinvent society, without being bogged down by legacy systems for property, economics, governance, and even ethics.

None of these challenges is meant to speak against the project of space exploration. There may be very good reasons for it, such as to ensure humanity’s survival in the event of a killer asteroid or other existential risks. But to where no human has gone before, we can go boldly but also thoughtfully. We probably don’t want it to devolve into a Martian Lord of the Flies or nationalistic land grabs that have been the source of wars here on Earth.

Where the Apollo and other historical missions were run by governments under a cloak of secrecy, the privatization—the democratization—of space today means that we now have a responsibility to open the policy and ethics discussion to the global community. Outer space and the future of humanity don’t belong to any one nation-state but to all of us.

This article is part of Future Tense, a collaboration among Arizona State University, the New America Foundation, and Slate. Future Tense explores the ways emerging technologies affect society, policy, and culture. To read more, visit the Future Tense blog and the Future Tense home page. You can also follow us on Twitter.