# How could the crew on a small spacecraft (6 people) on an isolated long (10yr) mission remain productive and harmonious?

Near future, Earth is starting to die, we send out dozens of small spacecraft to investigate promising exo-planets for habitability among neighbouring star systems:

• AI isn't smart enough to do the task for us - AI can help, but we need humans there to make descisions.
• The ships are travelling in a psuedo-FTL, and will be completely out of communication until they return.
• The journeys are going to take minimum 10 years ship-time to complete.
• Not much special training is needed: The requirements for these astronauts are basically a health check, "how to survey a planet", and some emergency drills.
• Life on board the ship in transit is low workload due to automation. Hydroponics, water, oxygen, waste disposal, is all mostly automated. 1-2hrs per week of human interaction is needed tops.
• Technology is relatively good - odds of a ship breaking down are slim, however the crew breaking down is another matter.

10 years is a long time for a group of 6 people to remain in close proximity and stay productive, we need to consider:

• They need to stay loyal to Earth - if they find a garden of Eden we need them to report it back, not stay there.
• When they get there (at the 5 year mark), all 6 of them need to work together mapping and surveying the planet.
• It will take a month if all 6 of them work together in perfect harmony.
• a year if only 5 of them are working in perfect harmony.
• and 5 years if only 4 of them are working in perfect harmony.
• Any interpersonal conflict risks segmenting the team and ruining productivity. A 1vs1 conflict reduces productivity but may be survivable, but a 5vs1 conflict effectively removes that 1 person from the team.
• Any fraternising within the crew is going to be hard to avoid - the crew will have emotional, intimate, and sexual needs that are borderline impossible to healthily suppress for 10 years. (Could a human really go 10 years without cuddles?)

So:

• Sending 6 professional astronauts with a "no fraternising" policy is probably the default choice, but leaves them emotionally and intimately starved until someone breaks that policy. The first 2 to break that policy get "rewarded" with intimacy - and could result in jealousy and all sorts of team-destroying things.
• Sending 6 straight people of the same gender also leaves them emotionally and intimately starved. There may also be a coming-out which creates the same fraternising dynamic we're trying to avoid.
• Sending a family unit (Like "Lost in Space", but teen or adult children), is an idea I'm playing with, but if husband and wife relationship breaks down messily the entire crew dynamics is lost as kids pick sides. Not to mention the teens go through puberty alone.
• Sending 6 people in a long-distance relationship with people on Earth may help ensure they return, but is also asking for affairs, which is going to destroy the crew with drama.
• Sending 3 couples may work - but odds are pretty high you're going to get at least one breakup. Possibly affairs even.

So - how should we structure the crew of departing spaceships in order to maximise the odds that they arrive as a functional unit, perform their survey, and return?

• Comments are not for extended discussion; this conversation has been moved to chat. – L.Dutch - Reinstate Monica Oct 13 at 18:02
• Clarify please - is there a hard limit of six people? Something that stops you sending two "spares" for a total of 8, or more ? – Criggie Oct 13 at 23:51
• I think NASA has spent quite a bit of money already trying to answer this exact question... – Vilx- Oct 14 at 16:41
• If you insist on sending a human crew you will need to greatly 'up' the man hours of maintenance work they need to do and reduce the level of overall AI control over systems humans can run without much support. The Hydroponics & recycling systems would be a good place to start. Your crew needs to be kept busy in shifts for hours a 'day' even with distractions like VR. Growing their own food would be a good place to start. That and other routine maintenance. – Mon Oct 15 at 1:37
• Fascinating though it is, How is that not off-topic as a real-world Question, according to Worldbuilding SE? – Robbie Goodwin Oct 17 at 21:27

I think there are several different ways this can be solved:

### Send professionals and risk it

Honestly, just send teams of 6 trained astronauts and hope for the best. This is probably what's going to happen. I highly doubt NASA would admit that their professional astronauts would break protocol (even though I agree, there would be a decent chance of failure over such a long time frame).

As part of the psychic evaluation, check how they respond to situations they judge as unfair, to feelings of betrayal, humiliation, and all those other negative emotions which can come with being stuck for 9 years watching your ex bang your friend 5m away from you. Filter out anyone who cant remain stoic under these circumstances.

Give all the astronauts an STD check, a reversible implanted contraceptive, and wish them well.

### Aromantics (Or Aros)

(Aromanticism is a part of LGBT). Send astronauts who identify as non-romantic, they may feel familial love, and / or platonic love, but don't feel intimate, romantic love. Its hard to get exact figures but about 1% of people identify as asexual, and about 1 in 5 of them identify as aromantic. (Although there are aros who aren't asexual - it's just this is the only stats I can find).

No romantic love means no heartbreak when it ends. 6 Aros should be able to work through the entire 10 year mission, while they may have other interpersonal issues, there shouldn't be any dating / jealousy / lovesickness to interrupt the mission.

### Send polys

Send groups of 6 polyamorous people, each of whom is dating at least 3 other people in the 6.

Nothing helps deal with the heartbreak of a fight with your girlfriend than going to cry on your other girlfriends shoulder.

Everyone has multiple intimacy sources and there are multiple solid communication paths. Any conflict has at least 1 mediator who is intimately connected to both parties. Your astronauts will be familiar with jealousy mitigation strategies and being open about their needs and feelings. While individual links in the poly may break down over the years, there are backup links allowing everyone to keep some emotional intimacy and a support network.

Being poly is a skill, so I'd suggest sending older polys (ages 40s - 50s), rather than younger ones, as they've had experience learning the nitty gritty of communication and jealousy management.

### Hire interpersonal relationship "Specialists"

Sounds like its easier to train someone whose good at interpersonal relationships to be an astronaut than the other way around. So, hire 3 astronauts who are stable, stoic, and meet the other minimum requirements, and work out exactly what they like in a romantic partner.

Then hire 3 "companions" who match the preferences of the 3 astronauts for a 10 year job where they're paid discretely to subtly befriend, flirt with, tick all the boxes of, fall in love with, and be the emotional support of, their targeted crew members.

The arrangement should remain a secret - the astronaut should think its just good luck that they found such a perfect match for the long trip.

\$400/hr, 24/7 for 10 years is \$35 million - small change when it comes to the cost of a space program.

### Children with puberty-delaying hormones

Send 6 * 10 year olds who are straight A students but shy socially. Have multiple AI guardians who cares for them like a mother, father, teachers, cool uncle, and other traditional role models.

Give them hormones to delay the onset of puberty, and keep them busy with complex school assignments and projects. Surveying the planet is their major high school project. Keep the hormone treatment up for the return trip, weaning them off in the final year.

When they return, they have finished high school, probably got a degree, and are 20 year olds who are just starting to discover what their bodies can do, and can then have a normal life.

### VR Pods

Working with a team is much easier if you get a lot of time away from them. So outfit all 6 quarters with state-of-the-art VR decks, and let the crew spend 80%+ of their time doing whatever they want in VR. By giving them space, an outlet for any emotion, and pseudo-companionship, they're unlikely to tire of their fellow crewmembers before the big surveying operation.

• Downvoted for focusing only on sexual interactions. – Alice Oct 11 at 19:48
• @Alice which one of the 6 potential answers did you think focuses only on sexual interactions? Intimacy != sexual. – Ash Oct 11 at 21:11
• @Alice Re poly relationships, most of it is about not being jealous, not just "yay sex with everyone". Any relationship is about more than just sex. If you're not jealous, the fact that one person may start to prefer someone else in the crew other than you is much less likely to upset you, because what matters is that they're happy. (The word is "compersion".) For bonus points, a poly crew who are all same-sex gay or lesbian could remove some of the gender-stereotype issues too. – Graham Oct 12 at 14:49
• @Alice Sexual relationships (not merely the sex) will be a big problem if they go badly. He's right to focus on them. – Loren Pechtel Oct 12 at 20:31
• "No romantic love means no heartbreak when it ends." I'm ace/aro. Can definitely personally confirm, this is not true. I've definitely experienced something that felt a lot like how alloromantic people describe heartbreak. It's not exactly the same, but it's not so different either. Not to mention, aro people form intimate but nonromantic relationships pretty regularly. They look different, but they're no less emotionally impactful. Ultimately, I wouldn't expect aro people to be any better at dealing with 10 years of isolation than alloro people. – Tesset Oct 13 at 16:13

Your crew members all have Down's syndrome.

Downs syndrome is an inborn chromosomal abnormality that comes with characteristic developmental and cognitive differences. One Downs syndrome stereotype is that individuals with this condition are passive, mellow and easygoing. All persons with Downs are intellectually disabled to one degree or another but 20% of adults with Downs syndrome are competent and capable enough to do paid work. Such people comprise your crew.

A narrative approach – Down Syndrome

We have identified a lot of differences between DS children based on their scholar integration. If in special school they are described as “good, loving persons, docile, disciplined, very sociable, gentle, and available to participate to activities”, in mainstream schools are considered “slow, passive, with pronunciation and reading – writing disorders, labile attention, and mechanical memory”. A possible explanation of these differences of teachers and other specialists’ attitude could be teachers’ tends to make comparisons between normal and DS children, which is not a correct attitude especially today when National Education law is recommending a differentiate and individualised curriculum approach.

Of course people with Down’s syndrome are individuals and come in all kinds, but leaning into a positive stereotype could work for a fiction. Especially good for a fiction is the idea of leveraging the good aspects of a congenital syndrome often considered to be disabling across the board. If this has been done I have not seen it. The prospect of space explorers who are all cognitively disabled but preternaturally sociable and friendly would make for a very interesting fiction.

• While I suspect most readers will believe this answer to be flippant, sarcastic, or somehow uninformed - it's the most insightful and imaginative answer so far. In fact, I can easily imagine someone with DS being more loyal to the mission after finding the proverbial Garden of Eden than anyone mentioned in any other answer. – JBH Oct 11 at 16:32
• +1 Yeah I agree. This disability would seem ideal for this kind of mission. – Ash Oct 11 at 18:56
• High sociability is definitely a plus, but the possibility for romantic shenanigans remains. – Jann Poppinga Oct 12 at 6:51
• I find quite poetic that hope for a new future for mankind would come by a crew with Downs syndrome. Well done. Of course a proper educational system would be needed. Might be a good idea to start implementing it now. Just in case. ^.^ – Duncan Drake Oct 12 at 10:50
• While it should be fine if everything goes well, an unforeseen emergency or otherwise non-textbook situation would limit the effectiveness of this approach. Perhaps those on the autism spectrum would be a better fit? – mcalex Oct 13 at 6:07

I've always been a bit sceptical about the idea that boredom might pose a serious threat to long-term space missions, because, across the world, there are millions of people who live lives that seem to me to be equivalently boring to a ten-year space voyage. A lot of people have jobs that offer them no significant time off, no significant variation, and no significant mental stimulation, and they basically manage fine - don't get me wrong, I wouldn't want to switch places with them, but we don't see these people routinely having mental breakdowns or committing suicide.

This might be a bit of a flippant point, but maybe the space agencies are creating a bit of problem for themselves here by trying to create strategies for providing adequate stimulation for astronauts, people who by any metric are used to living some of the most high pressure, high variation, high excitement lifestyles of any group of people who have ever lived...

So, to go back to your question, I think the ideal structure for the crew would two men and two women, in established heterosexual relationships, with one child each between the ages of 4 to 8. The adults should not be selected from the astronaut corps, but from the general population, they should be people in career backgrounds like manual labour, agriculture, haulage, people who are temperamentally suited to doing roughly the same work, every day, day in day out. People who aren't motivated by things like fame and notoriety, but just the simple pleasures of work and family. In short, the sort of people who aren't very likely to have signed up to be astronauts in the first place, but, in the extreme circumstances you outline in your question, might need to be pressganged or coerced into the job required of them.

As you note in your question, the actual amount of work needed on the ship is very small, so once these astronauts have passed the physical requirements, they will hopefully need only quite limited training initially. What should keep them busy for the majority of their time in space not spent on their assigned tasks would be training themselves up via educational computer programmes onboard the ship to be ready for their duties once they reach their planet, and, crucially, educating their child to be ready to be able to contribute to the mission upon arrival. The two children would be well into their teens by the time the journey ends, and should be able to pull their weight in the jobs required of them, in fact, given that their education will be specialised from an early age towards these skills, they might even be more adept and more productive than their parents at these tasks.

Crucially as well, each of these children will have the other as company. So too will the adult couples have the other. In terms of managing the risk of family breakdown, I think the best policy is to enforce a culture of openness and honesty between the two couples. I think mandating that these couples agree to be in a polyamorous quadrangle with each other from the get-go is probably going too far, but if a situation comes up where one of the adults develops feelings for one of the others, the best thing would be if there was a culture where these things could be raised and negotiated openly.

So, in short, I think the best way to keep your astronauts occupied is to rely on what has most successfully kept most people occupied throughout history, the full time work of raising and educating children.

• Hmmm, not too far off from the Lost in Space family: two children, two young adults, and two older adults. If only that zany Dr. Smith had not interfered! – DrSheldon Oct 13 at 14:49
• A bit of a paradox, no? Those most qualified by your measure would be too risk-averse to apply. – Jann Poppinga Oct 14 at 10:02

The Argument for One Person

Although he described his solitary confinement as "the most torturous experience a human being can be put through in prison. It’s punishment without ending," Albert Woodfox is the longest-serving prisoner kept in isolation (a tiny cell, by himself, massively limited social interaction) in U.S. history. 43 years. (Source) He appears to be healthy, sane, and capable of living the remainder of his life.

Consequently, IMO, a single person is more likely to survive the trip than any group of people.

The Argument for More People

NASA has 20 years experience with the International Space Station and while that's not quite the same as what you're proposing (Russian cosmonaut Valery Polyakov spent more than a year aboard MIR, but that's not the same as ten years), they have learned that skills in communication, leadership & followership, self-care & team-care, and group living are essential for survival.

The Argument Against Multiple People (consider this a Frame Challenge)

On the other hand, the Biosphere 2 facility is perhaps the most on-target experience concerning long-term human interaction.

Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts, though heavily publicized, ran into problems including low amounts of food and oxygen, die-offs of many animals and plants included in the experiment (though this was anticipated since the project used a strategy of deliberately "species-packing" anticipating losses as the biomes developed), group dynamic tensions among the resident crew, outside politics and a power struggle over management and direction of the project. Nevertheless, the closure experiments set world records in closed ecological systems, agricultural production, health improvements with the high nutrient and low caloric diet the crew followed, and insights into the self-organization of complex biomic systems and atmospheric dynamics. The second closure experiment achieved total food sufficiency and did not require injection of oxygen.

Your crew would obviously not have problems with outside politics, but I could imagine there being a struggle over management and direction of the project as part of the crew dynamics.

IMO, and despite NASA's experience, no group of people, no matter how large or small, confined to a small area with basically nothing to do but hobbies (at best) for a long period of time (10 years) will survive the trip without trauma. It doesn't matter what their physiology, philosophy, education, or anything else is. Humanity evolved in a competitive environment and you're assuming there's some mix of something that will set that genetic imperative aside for the time and purpose required. There will be rapes. There will be beatings. There will be deaths. In my opinion, a crew surviving that trip in perfect condition is nothing short of magic.

So, if you insist on sending a group of people, what can you do?

1. You need to justify why humans are there at all. Humanity has never sent humans to another globe without first sending satellites, probes, rovers, etc. We're actually pretty good at it. Worse, you've described a situation where the humans already appear to be irrelevant. Everything's automated and the odds of the ship breaking down are slim. What choices need to be made that even today's computational technology couldn't resolve for the purpose of describing the habitability of a planet? It's as if you know in the back of your head that the advanced tech needed to do what you're suggesting already precludes the need for humans to be present — but that's not the story you want to write so you're trying to crowbar them in.

2. Humans need a LOT of things to survive long periods anywhere in space. Exercise, jobs, hobbies, privacy, company.... But you've automated everything. (a) You must unautomate something (if not everything). (b) You can't send a small ship. In fact, the Hermes in the movie The Martian is a reasonably good example of fiction reflecting anticipated reality. The ship's huge with living quarters, a gym, cooking facilities, yadda yadda yadda. And then there's comms, engines, fuel, equipment, plant life, yadda yadda yadda. Your ships will be huge just to send six people. You might as well send 60 and make life easier for everyone.

3. It's nice to believe that the physiology and philosophy of any individual or small group of people will have a significant impact on the survivability of the mission. But...

Rather than risk offending anyone in the current SE "we don't want anyone to feel hurt" environment, let it suffice to say that almost no one fails to change in some way, large or small, in a ten year period. Physically, mentally, spiritually, emotionally... Whatever your starting condition is, it will NOT be your ending condition. In ten years someone could find themselves with cancer or start questioning everything they are or believe.

...I'm merely pointing out that a small group of people cooped up in a small space with nothing but hobbies and entertainment for ten years are statistically more likely to proverbially rape, pillage, and plunder no matter what their starting condition is than not. Your statement that "not much special training is needed" is the most unbelievable statement in your question — Your crew will need the highest interpersonal training (and screening!) of any group of people on the entire planet.

Conclusion

Either send one person or send a lot of people. I enjoyed Lost in Space as a child, but the show didn't show ten years of development. The family never changed. Never grew up. The movie and the latest series aren't a whole lot more realistic.

If you insist on sending just six people, you must change the nature of the trip so they are up to their ears busy. And even then I consider surviving the trip without conflict to be miraculous.

Or you need to do what authors in the past have done: ignore justifying it and just write your story.

• I think that, ignoring any mental health concerns, sending only one person is too risky because there's just too much of a danger that they get into a situation where they need someone to help them. For example, what if someone falls down a ladder and then dies because they can't drag themselves to the autodoc? What if they get their arm stuck in machinery and can't get it out because the wrench is just out of reach? Similarly, I just see too many scenarios where exploring an alien world ends up with mission failure because the solo explorer needed some extra limbs to help them out. – Dragongeek Oct 12 at 14:50
• @Dragongeek You've made a point - but everything's automated and there's a slim chance of the ship breaking down. The OP has failed to prove the need for a crew. All of your concerns are trivially overcome by sending a satellite, probe, or rover. And the tech level required for the scenario suggests automated medical that would take care of all but the most immediately dire circumstances. When you say "too risky," methinks it's based on what you understand today and not what you predict for the future. – JBH Oct 12 at 14:54
• Arguably, OP's need for a crew is authorial fiat, so I think we agree. From how non-skilled OP describes their crew members as being and how advanced the technology is, I can't imagine that they wouldn't be able to automate everything--even if they can't make a true AI. – Dragongeek Oct 12 at 14:58

Send a lot and hope

This is not dissimilar to the underlying concept of the Heechee Saga.

You're already willing to send unskilled people. Making unskilled people is cheap.

Make your spaceships cheap too and send a lot out. Some will go mad. Some will kill each other. Some will just stay on the planet (you probably want at least some kind of automatic notification when a planet is found with a breathable atmosphere so you could send a better crew if the first lot of losers didn't respond).

Send enough and you'll get lucky.

• This is bascially how North America and Australia were colonised by Europeans. – Oscar Bravo Oct 12 at 10:13

Give the job to a religious order

There have been plenty of well adjusted, functioning adults who have deliberately chosen lives in community with limited contact with those outside the community through our history. The most common manifestation of this phenomenon are those who choose said lifestyle for religious reasons. Find (or found) a religious order who will undertake this planetary survey mission.

Note: Being a Roman Catholic monk myself, I am most familiar with this phenomenon in that context and my natural language for describing it comes from that tradition. However, you can probably find groups with the necessary characteristics in other religious traditions as well if you want more religious diversity.

• Do we want to make first contact with priests? – Tom Oct 14 at 12:45
• @Tom I could think of worse options. Also, we're primarily hoping to survey planets, not make first contact. – Ben Barden Oct 14 at 13:45
• There are plenty of reasons why we would not want to expose aliens to religion. It could be terrible for them (didn't work too well for anyone on Earth, not for Africa or the Americans, nor for anyone "introduced" to Islam, aside from the Romans, few of us spread their religion peacefully) but it could also be bad FOR US. In the greater universe, religion might be considered something bad that justifies extinction. We might want to keep such things from the aliens until we know the rules of the galaxy. – Tom Oct 14 at 17:14
• @Tom While it is popular today to blame religion for everything, the reality is that the religious orders have done amazing charity work and developed many societies, and were primarily responsible for the proliferation of medical technology. The problem in a worldbuilding/colonization context would seem to me to be the special interests that are funding the religious group. By itself Buddhism/Christianity/etc. are mainly peaceful, aligned with a greedy colonization force they're not. In this case mission work is not the point and neither is integration, so it might work fine. – Jackson Dunn Oct 14 at 19:15
• We can have different opinions on the reality of religion. I disagree with all you say. I postulate that there is a non-zero probability that more advanced aliens share my opinion or have an even more radical version of it. That first interaction might get humanity marked as "dangerous lunatics". Or imagine the aliens have a DIFFERENT religion. That typically didn't end well on Earth, either. They might decide to extinguish us as heretics. I can't imagine a scenario where it would be to our ADVANTAGE if first contact is made by a priest. – Tom Oct 15 at 6:31

The problem as stated quite possibly has no solution.

The problem lies with these two requirements. "Life on board the ship in transit is low workload due to automation. Hydroponics, water, oxygen, waste disposal, is all mostly automated. 1-2hrs per week of human interaction is needed tops."

and

"remain productive"

At present, I know of no human capable of 10 years of ENFORCED IDLENESS, while still maintaining the habits of productive work.

You will need to give the crew something to do, something meaningful that uses their skills. Not merely continuous idleness, nor continuous retraining, nor obvious make-work.

Or, you will have to remove the time factor. Suspended animation, memory wipe of the voyage, drug-induced oblivion while in transit, or something similar.

Or... How about SPARES? You need 6 people, of no particular skillset, cooperating perfectly? Send 50, and select the "Active crew" only on arrival.

• If we take a loose definition of "remain productive" and include hobbies and video game progress in that, then it seems that the crew should just be a bunch of hobbyist nerds. Pretty sure I could play or make games for 10 years without too much boredom. – LukeN Oct 13 at 17:50
• I think the pandemic has shown us that 3 months of enforced idleness is too much for most people. – Beefster Oct 16 at 16:10

The only solution I can think of?

Raise multiple teams of infants (6 in number) from birth in the confines of a space designed to replicate the ship they will be traveling in. Give them the best AI driven artificial reality sims you can create AND the best teachers, psychologists and doctors etc you can find as 'remote' mentors and teachers/evaluators.

After 18 years or so select the most 'sane'/high achieving group you can identify i.e. those with the highest probability of success and send them on their way with the best high bandwidth VR entertainment and social networking/counseling support systems you can develop in the time between initiating the program and launch. (While of course euthanizing the other teams.)

Then just pray to God you aren't one of the six poor bastards chosen for the final mission/experiment

• Gratuitously murdering the nonselected groups cranks the "evil" level on this one way up with no actual gain. Also, this plan near-guarantees that the group has little to no loyalty to earth (especially if they figure out what's actually going on) leading to a high likelihood that if they discover an Eden plnet, you wont' know about it. – Ben Barden Oct 14 at 13:48
• If you're evil enough to conduct the 'experiment' in the first place, knowing in advance (as you would) the years of psychological stress you will be inflicting on the children involved then I figure you're evil enough to dispose of the 'failed candidates' afterwards. The only excuse is sheer desperation (which it might be in this instance). If the mission is so important it cant be allowed to fail you'd probably do what you could for the other 'recruits'. I still think AI's & rovers etc would do a job better if the aim is purely exploration & survey. All that saved mass on food & water etc. – Mon Oct 15 at 1:32

Emotions are normal biological functions. There is no healthy way to suppress them. It is however possible to learn to manage them in constructive ways.

You could just accept that there will be drama. Send people with high emotional intelligence and trust them to deal with their emotions in a non-destructive way. For this strategy, I would include one or two psychologists in the crew and have mandatory weekly appointments for everybody.

A couple, three children, and a grandparent of proven emotional stability. During the outward voyage the adults are occupied training the children to be competent planetary surveyors, on the return voyage they're forcibly placed in hibernation even if there's a health risk since the important thing is their reports and stored media. Two or more ships per planet with the AIs directed to keep them unaware of each other.

Everyone has unique needs and expectations and when these are not met, issues start to arise. Any conflicts that arise during the mission are due to unmet needs and expectations so here's what should be done:

CRITERIA FOR SELECTION:

Firstly, a professional psychologist must thoroughly evaluate each and every individual who has the potential to take part in the mission. Here the focus should be on the natural impulses that define individual character. Things like:

-Anger -Sex drive -Happiness -Jealousy etc should be explored.

At the end of the exercise we should have a better picture of each and everyone's behaviour.

Next step is to identify individuals with traits that are productive and won't unnecessarily jeopardize the mission. If a person is shot-tempered, anti-social and other attitude that causes disharmony, that person must not be part of a mission.

Remember, other factors like technical skills etc remain constant so the main decider of who travels is the attitude of the individual. All have qualifications.

Someone who has core values that promote teamwork, respect and all the good behaviours is likely to see that the mission succeeds.

Don't expect a stingy bunch to report back when they come across the garden of Eden

It comes down to their individuals behaviours.

NUMBER OF PEOPLE:

As for the number, I don't believe in sending 10 or less. It has to be a small community with someone in charge, a deputy, others who can follow orders without causing trouble. It's normal for human beings to lead and to be lead, and there has to be a balance.

The group has to be a team with a leader, maybe + 1st and 2nd deputy, security guys, those who do the heavy lifting and a 2 or 3 individuals who are the brains.

SEX:

Thanks to technology there are robot sex-dolls now. They go a long way in quenching any sex impulses for those who can't control the urge.

For those who don't like the idea, chemical castration is another option to reduce libido

They could go into hibernation except for when they will have to do work. They could just pick three random people from each gender to hopefully have some love on the ship. The ship would have to be huge and most likely cost billions of dollars to make. That is because it will have to be able to store all of the food and water that the crew may need. They will need billions if not trillions of dollars of fuel which will mean make the space ship even more massive!

• It seems like a massive weak point in mission planning to spend billions of dollars building a ship, billions more fueling it, and then putting six random jabronis in charge and hoping for the best. Also, water recycling is quite efficient (90%), so long-term missions don't really require all that much more water than short ones (3x the amount for a mission 10x as long). – Nuclear Hoagie Oct 12 at 18:33

Any crew must have a leader. Otherwise, decisions are going to take too much time, let alone quarrels are inevitable. That is why ant military professional now that a team leader is the most essential. The whole team must guard their leader and clearly know whom to obey if the current leader can no longer lead.

What you have plotted is a fantastic mission. Well, impossible is possible. My suggestion for such a team is to get an experienced team leader and stick to strict set of rules.

https://www.dailymotion.com/video/x18beia

• Even civilian air flights have a commander, and one can't really be ordered to like someone else. – L.Dutch - Reinstate Monica Oct 12 at 12:26
• "That is why ant military professional"... Ant? – NomadMaker Oct 12 at 18:51

The existing answers focus on how to keep the crew happy. This is not necessarily the same as keeping the crew productive.

Everyone is trying to figure out how to best make the interpersonal relationships ideal and harmonious, but when the mission time is ten years it is hard to predict what conditions are or will be ideal - and more importantly, it's nearly impossible to predict how those ideal starting conditions can be maintained. People change over time. Maybe your polyamorous crew decides it's not so polyamorous any more. Maybe your scientifically curious and highly professional crew abandons its curiosity and professionalism. Etc. I offer the following in the spirit of being a Devil's Advocate, and ask you to consider whether your problem disappears if you take the exact opposite approach.

Luckily for the success of our mission, kindness, reason and collaboration are not required for all organizational structures. In fact, for most of human history we organized ourselves along principles that lacked all three, to a substantial degree - but work still managed to get done. It got done on the basis of hierarchies employing violence.

We can mimic this (basic and time-tested) solution by sending one principal explorer and five servants. The principal explorer's control over the others will be technologically enforced, using implants that cause the five servants severe pain if they disobey; a literal dead man switch will also make the principal explorer's death fatal for all five servants.

This gives you a single point of failure instead of six. As a result of the principle "It's good to be the king", the principal explorer is likely to reach the destination more or less intact and in good spirits. And they will simply force the others to work. The crew is not likely to turn its back on Earth if they find a Garden of Eden because to this crew a Garden of Eden is not possible; the principal explorer's domain only extends as far as the ship, so they are not likely to leave it or allow the others to do so. Having the principal explorer's technological enforcement tools turn themselves off if they don't launch back to Earth on the right timetable will also create a powerful incentive to return, since the explorer's other choice at that point is likely to be the horrible revenge of their fellows.

• Getting people to sign up for this might be a trick. There's also a number of ways it could end messily... especially since the principal explorer may not enjoy their reception when they return home (and will know to expect that). For that matter, the other five crew would have serious incentives to figure out ways around the technological controls. Given five years, they might well manage it. – Ben Barden Oct 14 at 13:54
• @BenBarden I thought about the problem of getting volunteers - but if we offered people the opportunity, today, to sign up for a literal suicide mission to Mars, I think we would get 6 qualified volunteers. At least the first few interstellar missions would probably be similar. I think we might also consider selecting the principal explorer by lottery only once the mission is underway, to give all volunteers the possibility of being on top of the pile. – tbrookside Oct 14 at 14:11
• ...except that the requirement is for dozens of small craft, not just a single mission... and if you're setting it up as "select by lottery once underway" that's even more likely to lead to massive friction... or to the folks on the trip finding ways to break the lottery system. Oh... and "obedience deriving from force" is workable for getting physical labor out of people, but it's terrible for productivity in more intellectual work... especially when the oppressed have a strong incentive to keep the ship from departing long enough for the controls to turn off. – Ben Barden Oct 14 at 14:34
• @BenBarden On a planet of 8 billion people, the difficulty of getting 600 volunteers is not that much greater than the difficulty of getting 6. And while any of the other answers would probably be more productive per person, if they succeed, I looked at the question more from the perspective of minimizing the possibility of failure. I read OP's description of the work required as low-level intellectual work that did not require extraordinary ability of qualifications but which was (for some reason) beyond the ability of an automated system. – tbrookside Oct 14 at 14:48
• @BenBarden Your comment about the game theory here and the incentive the "servants" have to overcome the system is definitely well taken though. I'd have to think that through. It's a bird feeder problem and it may be insuperable. – tbrookside Oct 14 at 14:50

No one has mentioned customized, intelligently used psychotropic drugs. To pull this mission off, no matter what the other parts of the solution set suggest, will still require pharma support.

# Framing Challenge: A one-way trip might be better

## Getting Rusty

There's a problem you haven't actively acknowledged: how do you maintain essential skills for 5 years? A training at the beginning of the voyage will do nothing for a crew that does not need to use the skills until 5 years later.

You will need simulators. This also has the added benefit of keeping your crew busy as well as cutting the cost of upfront training. Fortunately, this is pretty much already possible with a good VR system.

You will also need artificial gravity on this ship to avoid muscle and bone atrophy. A few months in microgravity is enough to lose enough bone and muscle mass that you can no longer endure gravity.

## The return journey

The mission is complete and there is nothing more to do. How do you keep your people occupied and happy so they can report on their findings?

I don't think many people can deal with having no sense of purpose for 5 years. Even if you had a mirror of every streaming service onboard, your people are going to be bored and depressed watching TV all day, every day, for 5 years.

## Social needs

Realistically, 6 people on the crew is probably not enough to manage social needs, let alone sexual/romantic needs. Some of this can be sidestepped with extreme introverts, but 10 years of seeing nobody but the same 5 people is going to be a real challenge even for the most extreme introverts.

# Solution

Send more people and colonize instead. A crew of a few hundred people can seed a new population on a new planet. Instead of sending a crew back to report, set up a high-power transmitter to report. It will take a few decades to reach Earth, but that should be good enough. You have a viable new home for Humans, so it's totally okay if they are never able to send the rest of the people.

This also has the added benefit of saving fuel.