Why are interstellar colonists lone rangers? (Not-so-far future version)

Question

This question is inspired by Why are interstellar colonists lone rangers?. I know that many of its answers are also suitable for this questions. However, I am more interested in ideas that work with harder goals and without extremely-far future technology.

---

The year is 21XX, and humans are sending their first manned spaceships to venture out of the Sol system. They are several (I would say <100) sleeper ships sent toward different star systems to explore and colonize them. The journey would take several hundred years for the ships, while the human onboard sleeping for most of it. Each ship carries one and only one human on board.

The question:

• Why carry any human at all?
• Why carry only one human, instead of a small team or even more?

---

You are free to define the story background to match your reasoning, as long as it roughly follows this:

1. Humans have colonized some parts of the Sol system (so they could construct these ships from space). Exactly how much or how little depends on you.

2. The target star systems are already analyzed from within the Sol system, e.g. with various telescopes, and can even be imaged using solar gravitational lens. However, no probes have been there (except for Breakthrough Starshot, if you really need that).

3. No FTL technology of any kind have been developed, nor to be developed in the foreseeable future.

4. Fusion drives are available, but they are nowhere near interstellar torch drives. For example, to get 10% c delta-v, you would need a mass ratio of about 10 (91% of your ship is fusion fuel), and run it continuously for several years.

5. There can be advanced AI technology somewhere around AGI level. The exact settings depend on you.

6. The sleeper ships can protect the crew throughout the journey from radiation and other space hazard. The crew will not age when sleeping.

   The ships will carry enough necessary machines, tools and resources for the crew to explore and colonize the target star system, which may include some far-future style technology (otherwise the story won't work). Assume that any amount of humans (including zero) would complete the job, although less human would mean more time and less output.

7. The human on board is not sent away because of a punishment of any kind (or at least he/she does not see it as such), and has received proper training before leaving.

---

Like the original question, I already have some answers in my head, although they are not very solid. I will rate on how much they would force the formation of a one-man man team, since that's the core of the plot.

Answer 1

To test if the planet can sustain human life

Sending a human can tell us something no probe can... if the planet can sustain human life. If you send a probe, it can rule out lots of worlds, but there will also be many that look habitable, but have flesh eating bacteria, or pollen in the air that turns out to be highly toxic.

This means that the odds of an Earth Like planet ACUTALLY being livable on arrival may be low. It could be that out of 100 colony ships, 95 will show up to find out that the planet is too hostile for human life in some unpredictable way; so, we need to send the minimum number of humans to "test the waters". If each ship has 1 person, and your program sends 95 people off to die horrible deaths, it is a lot better than sending crews of 50 people, and sacrificing 4750 lives.

Once she gets there of course, she will need to test to make sure that human reproductive systems still do thier thing, so she will need a sperm bank to impregnate herself, and make a second generation. She will also need to test things like growing editable foods, processing drinkable water, etc. If her children grow up and are able to reproduce as well, then they send a signal back to Earth giving the all clear for much larger colony ships to be sent. If she dies, then the AIs will her examine her corpse, and send the cause of death back to Earth.

Answer 2

AIs tend to be unstable

In the advanced world AIs have a tendency to get caught on loops and crash, be unable to handle novel situations. As such, it's normal to send a programmer along with the expedition. While the terraforming and colony prep can be done by automated systems, having a human along with the AI means that if there's an error they can fix it.

The human is backed up.

The ship has facilities on board good enough to clone the human, and the human has enough cybernetics to transfer their memories to their clone. Carrying extra humans would be very expensive, and as such it's easier to just have a single human who you can replace if they die.

Each human is fond of the AIs

Each human is the sort of person who prefers AIs to humans. They have AI romantic companions, AI buddies, and generally don't like humans as much. This mission is a dream come true for them, because they get to spend all their time with their favourite people and no annoying humans.

Answer 3

They only had enough volunteers for 1 person per ship

Let’s say we have 500 sleeper ships going to 500 different locations. Of the entirety of the Space Force, only 500 people who volunteered for the mission made the cut. They thought to cancel some of the sleeper ships, but they were already built and loaded before they could cancel, and people can only go into stasis once. This dooms your “Lone-Ranger” attendant to work on their own.

The biggest benefit I see is that now they don’t have to file/pay any taxes.

Answer 4

Possible options for only one human (I don't think existing answers mentioned them):

1. Something specific in the mission requires a loner psychological profile. Perhaps an extreme introvert, maybe combined with some sort of Asperger's spectrum. For lack of a better plausible reason, let's say they are best adapted to interface with ship's AI/computer.

   This gives impetus to NOT send more than one person, since such types of people are best solitary, and other people range from unwelcome distraction to constant energy drain to active impediment.

2. Some Higher Power (supernatural, or some alien civilization - perhaps one that rented humans the technology for exploration) doesn't want humans to pull a "Jurassic Park" move and reproduce. But they don't know about sexes, so to them any # of any humans greater than one spells "reproduction".

3. Simple one - literal technology limitations.

   Spaceflight is inherently limited, always. At some points we couldn't built rockets able to lift more than one human to orbit. Galactic exploration poses many more varied technical challenges.

4. Human brain activity interferes with some soft of functioning of the ship or its computer. You can shield from ONE person but not from two (perhaps some sort of interference in EM fields generated by the brains of two different people? Or some mcguffinish explanation that has no basis in real science).

   • A version of this could be a (somewhat obvious and somewhat well known) issue with computer voice inputs - how is your AI able to follow voice commands from someone who's in a noisy crowd? At least on a ship, there's little chance of a second person yelling "format c:" at your Space Siri; but if the system is for example some sort of "read EM fields of pilot's brain remotely", reading brain signals of more than one pilot might not be realistically possible - imagine two people typing at the same time on same keyboard.

5. This one is more interesting, since it follows the idea that scifi trappings and such are just window dressing to talk about human condition. What's the reason? earth-side human politics. Perhaps doing one human at a time, was the only agreement international bodies could agree on. Perhaps some religion gained dominance which for some internal-religious reason demanded this (hello from L.Ron Hubbard!)

6. A version of the last one, but this time, the one human limitation is an internal dogma of whatever society is in charge of exploring - not even necessarily the whole human species.

   Interestingly, this does not need to be negative - for example, the society could place an inordinately high value on human life and risking it. Pilot-less missions won't work; so you have to risk at least one human. BUT, you don't need to risk more than one - so the societal rule imposes that only one is sent into risk.

7. Such exploration requires some unique abilities, which are incredibly rare. Wasting two such individuals on a single destination literally means losing a chance at exploring the second destination. This was an idea around space travel in, for example, "Wing Commander" movie (ok ok, you can stop throwing rotten tomatoes at me - so I like it, sue me); until NavSat AI could replace humans at navigating quasars. Not sure if that was a movie invention or part of game lore. Or for that matter, early Navigator Guild in Herbert's "Dune".

8. A bit of a silly combo of the last 3 - there aren't enough candidates, but the limiting factor isn't actually some unique SciFi ability - it's plain old money. You can only send a ship by financing it and buying the right to pilot it; and there's only so many zillionairs both rich enough to afford it AND willing to finance a ship. And the payout from the mission is too big for them to be willing to team up. This would probably work better if earth was split into late-medievalish absolute monarchies who tend to be even less prone to cooperative strategies.

As far as why carry any human at all, that's easy. AI isn't intuitive/flexible enough for fully autonomous missions. That's true today with for example chess or many other activities - human + AI always beats just AI even if AI beats most/all humans. Or, some reasons above can easily eliminate "no-human" option; such as religious dogma, rules, politics.

Answer 5

The artificial womb has been perfected - you can take a fertilized egg from a number of different species and produce babies.

But printing a full on gamite from just information is error prone and much harder. There are some details of the biological cell we aren't good at reproducing. Frozen eggs and sperm (and even embryos) result in an insanely better result.

There have also been experiments with raising creatures using robots and AI. The results are mixed - better than nothing, but not all that great. And there are horror show points in history where humans are raised by AIs, and it did not go well: raising a human using AI is considered a crime against humanity.

Sending a human alongside the other biological material is to provide a parent. Life extension technology means that the typical lifespan of a human is well over 3 centuries before the start of old age at this point; a single 100 year old human could raise a half dozen kids, recruit some of them to raise more kids, and produce a viable colony in their lifespan.

The ships arrive and using fully automated processes start building an industrial base.

The first phase consists of building simple asteroid mining bots. This gives you quadratic growth in resources.

The second phase involves building asteroid mining bot factories and control centers. This gives you exponential growth in resources.

Control of the asteroid provides enough resources to pick a planet or moon to build the first base on. This base is going to be temporary (but on the order of 1000s of years).

A nuclear fusion reactor, orbital beanstalk, solar collectors, repair bots, radiation shield are all constructed, then an atmosphere is generated and a biosphere is introduced; probably more than one biosphere for redundancy purposes.

Then the human is decanted. Their job is to raise the other humans, each produced by the artificial wombs. The humans produced in turn raise other humans in an exponential wave as the base is expanded.

Meanwhile terraforming is ongoing. Terraforming is expensive, but the machines have already built an above K1 civilization in orbit. Geological amounts of water are added to a suitable body, factories that produce entire atmospheres are built, etc - the goal being a life-supporting environment that can survive technological collapse on the scale of millions of years or more.

The new system continues its 3 primary goals

a. Create a new branch of humanity and AI

b. Create a biosphere capable of surviving technological society collapse

c. Build an industrial base capable of launching new probes further out

The estimated time to complete a is on the order of 100 years, b is on the order of 10,000 years and c is on the order of 1000 years. If 50% of attempts succeed, and they launch an average of 5 probes at 0.1 c, you get 2.5 probes for every probe you launched every 1000 years, or a doubling time of about 750 years. Every 7.5 thousand years the number of probes goes up by a factor of 1000. After 75,000 years you can have 1,000,000,000,000,000,000,000,000,000,000 probes in flight.

This is enough probes to colonize the universe (let alone the galaxy) -- the bounding problem is finding suitable destinations. So the wave of expansion is limited by travel speed (0.1c) and distance you can detect candidate systems.

As you can see, the exact time it takes to bootstrap to building probes is not all that important, nor how many the new colony launches. The exponential causes "finding viable target destinations" and "travel time" to dominate how long it takes to spread over the Galaxy.

Speed is only important insofar as if you take more time, a disaster is more likely to occur and prevent further reproduction.

But, going back to the reason, part of the project is spreading humanity, and humans need at least one parent. Sending two would literally double the cost of the expedition.

The backup plan if the parent dies is to attempt to raise single humans via AI. You repeat this process until a viable human is created, who then in turn raises the others. Based off of the previous warcrimes, this is estimated to require a few dozen failed attempts.

As the chance of the human dying is relatively low, this was viewed as an acceptable cost.

Answer 6

Colonies

Colonization is all about controlling land and stealing the resources of a foreign country to enrich your home country. The most efficient way to do that in interstellar terms is using AIs and robotic automation. Sending fragile humans only makes sense if/once you ever get around to terraforming or you happen to find a perfect planet. Humans won't be doing the real labor.

So why sent a human at all?

Laws and/or prestige/bragging rights

Either because it's a legal requirement to claim a planet in interstellar law, and/or because of the prestige that comes with having a person of your country step foot on a new country as the first human (why did we sent a human to the moon? why are we considering sending humans to mars? It's definitely not because it's a good rational idea). The value of the human is purely the fact that he is a 'human' with whatever cultural and legal implications you give that in your world.

Of course once you're sending a human anyway - a very very expensive project - you probably will try to maximize the value you get out of your investment, so you train them to be able to have some ability to handle unexpected problems, as humans are pretty versatile, but in a world with AGI's that's probably going to just be a minor redundancy at best.

Bonus: So why not sent prisoners or something along those lines?

Because more than enough people are willing to die for the honor of being the first to step foot on a new planet. Add some some decent benefits for their heirs/relatives and it's easily believable.

(Bonus: Classical minor plot twist)

By the time they arrive not only (cliche) has FTL travel been invented, but also did the law/culture change so that the idea of sending a human is completely obsolete .

Answer 7

To save mass.

Every gram saved is worth more than gold. Each human would require tons of mass such as larger spaceship rooms, more supplies, etc. The ships are small and efficient. The goal of the mission is to "bootstrap" the star system, make it susceptible to later, larger incoming starships with more humans. Early ones are the pioneers, a special selected crew. They are the most talented people who can come up with novel ideas and being creative when rigid AIs won't do, encountering a problem that is out of their training data. Human and machine work as a pair.

Bootstrapping includes exploring, terraforming, mapping, of course by using in situ resources. However, they might use nanobots, 3D printing, gene editing. They need to be very clever about that. And most importantly they need to build a huge laser platform that helps decelerating later incoming ships, enabling larger transports carrying less fuel mass.

Answer 8

Don't put all your eggs in one basket

The technology used is well tested, but has never been used on a such a long trip. With the length of time for the journey, the planners fear is that some unknown fault could happen.

Rather than have it cause a catastrophic failure and wipe out everyone, it was decided that having a single person ship was safest for the mission - if all works fine, then they can meet up at the target location.

If some fault develops in a colony ship, a single occupant dies. Not ideal, but better than having the entire mission team dead.

Answer 9

Single Passenger Ships are the Most Efficient Use of Resources for Reaching Maximum Number of Star Systems

Limited Resources can be packed within the craft

With such a long interstellar trip, the craft must store sufficient energy and resources for the trip such as fuel. This leaves limited space for a payload, which means a crew of 1 is better because 1 crew member can fit in a more compact area. Then of course there will be space taken up by the crew members supplies such as food, water, etc.

The technology to keep people in stasis is expensive

It would be prohibitively expensive to have several crew members per vessel held in stasis for their goal of reaching a minimum threshold number of star systems. It’s expensive enough with the individual method, and it was hard to sell the governing authorities on the cost of the single pilot system. If they tried to reach that many star systems with larger ships and more crew members, it would exceed their budget due to the increased cost of additional life support systems per ship, so to reach as many star systems as they can with the funds (and meet that minimum number of reached star systems requirement) they reduce cost of each individual ship by using single passenger ships which only require one life support system.

The technology to keep people in stasis consumes a decent amount of energy

The more pilots you support, the more power that has to be supplied to this system vs the thrusters. This means that with 1 pilot the craft can travel further and faster without as much energy being consumed by the life-support systems.

A single passenger system is better for reaching the most star systems because of all these variables

With an allocated budget, by saving cost on each of the individual ships, they can make more ships and reach more star systems than if they had ships with larger crews. So if you’re trying to reach as many star systems as you can with a limited budget, this approach makes the most sense.

Why carry any human at all?

Because a human will be required to start a colony once they reach this star system. As another answer mentioned, they could carry the required kit to start a colony on one of these star systems.

Answer 10

It's a difficult choice, but there are several reasons to only send highly vetted individuals on the first scout ships.

These individuals are highly skilled and trained - classical astronauts, the best of the best, all in their mid thirties. Their goal on the new planets: To prove that the planet is suitable for future colonization, and send the message back to earth.

The risks of sending seed groups are just too large, for all of humanity - small groups may decide not to send the signal at all, and claim the planet for themselves. An individual does not have that temptation. Groups could risk failing to send the message and prospering on the planet due to internal strife. Sending groups would not be cost efficient either, and since you rip them out of their social continuum, you don't find many sociable people who are up for the task.

Sending probes ahead may give you some information, but they lack the decision-making of a human-in-the-loop on-site, with low latency. They may miss some blockers to colonization, which a human may uncover.

Considered unlikely by the science directorate, but not impossible, the planets may have scentient life. A single human is reasonably non-threatening, and not a colonization ship - in case you do find life on the target planet, and do not wish to antagonize it with a colonial effort - again a major risk to humanity at large.

Sending more people on missions which are considered highly dangerous, with most crews not expected to survive 90 days post arrival, was also rejected by mission planners. There is enough time to cherry pick those planets with magnetospheres, minimum terraforming effort, and acceptable seismic activity, while the colony ships are being built as multi-century-project, that the loss of life for exploration can be minimized.

You didn't mention it, but these are certainly one way trips. But some get to be humanities first envoy to a sentient species. Other arrive on planets which looked promising from afar but are more like Venus. Their story won't be told.

Answer 11

They're a specialist at troubleshooting

The AI aboard the ship can do everything itself without needing a human at all... under normal circumstances. But sometimes things go haywire, outside the parameters of what the AI was trained to deal with. In circumstances like that, the AI throws up its metaphorical hands and wakes up the human troubleshooter. The AI is great at operating within defined parameters, but human intelligence is better at creatively interpreting and dealing with a novel situation.

Why only one troubleshooter? Well, it's very unusual that they would be needed at all. There's no sense adding weight for a whole team of humans that probably would never have to be defrosted.

Answer 12

Psychological profiling

Humanity's expansion across the solar system has come with a lot of both large and small scale shifts in human societies and psychology. A new phenomenon has begun of people who find themselves out of place among other humans, longing instead for a solitary existence in space.

There could be various contributing factors to this - automation or other 'utopian' developments could make life in current human society boring or unfulfilling; global warming, pollution and other disasters might have reduced the amount of natural beauty on earth, making the urge to explore harder to scratch; The introduction to outer space early in a child's development having unprecedented effects on their psychology; cybernetic, genetic and chemical enhancement to brain function that have been developed over time may have side effects on personality. It can be a very rare condition, but a far larger human population being supported across the solar system would mean that even this rare condition shows up enough to be significant.

The exploration program selects for these particular fringe cases - people who, rather than going insane in a socially deprived solitary environment, would excel. This mission scratches some special itch for them - they want to explore, to see other worlds, to break boundaries and see what no one else has seen, push the limits of science. This isn't a colonizing effort so much as a scouting one - these people are tasked with rating their assigned systems for such an effort and collecting as much data as possible and sending it all back to the solar system. That data may be used for colonizing efforts in the far future, but this particular set of missions is about learning first had about other planets - and about scratching that itch to explore, that need that certain people have to see something they've never seen before, to learn about the universe through first hand observation.

The society they are leaving is one that feels secure and stable enough to wait all of the years it would take for these missions to get to their destinations and start sending back data, but it is also a society that each of these people felt they didn't entirely belong in. Everyone on this mission knows they will likely die alone on the edge of the unknown, but this is something they chose, something they wanted. You could even give them a poetic name, something like 'Abyss Chasers,' or 'Cosmophiles.'

Answer 13

They're cheaper and more versatile than robots with scanners.

Sure, we can look at he planets through a telescope, but how much do we really know about that specific planet? What robot do we need to send? What if the situation has something we didnt anticipate? Now we have send a very expensive robot to waste.

By sending brave skilled volunteers (or "volunteers"?) we use one of our best skills: Human ingenuity. We're very adaptive, so we send a human acompanied with a few 3D printers and a usefull AI to help with design/calculations and we have a very creative sensor to send us back all kinds of useful info about our potential new earth!

Answer 14

AIs capabilities and actual sapience have been limited/curtailed by law and/or fear of a robot uprising

All the technical limitations / reasons to need one human like breeding are tenuous at best, but I think this limit is the more realistic one.

The true "general intelligence" of AI in this universe has been severely limited, the automatic interaction between some AI systems has been blocked and so on because people became concerned about an AI uprising.

So we do need one human "overlord" at the end that does all those tiny blocked pieces of thinking for the AI, decided which info AI a can send to AI b and to make the obvious decisions that the AIs were blocked from making.

All the breeding new humans, terraforming, building the colony (from adapteable blueprints) and so on can easily be done fully automatic. But legally, a human has to give the go ahead every step of the way

Answer 15

Bit simple but...

They aren't told they're going to be alone. They go to a facility and are shown 500 ships. They don't know that each is being sent to a different star. They are told each ship supports a single person. They go to sleep and wake up to be told the good news.

As to the why, you get 500 shots at finding a Sol type world instead of of 50 or 1.

Answer 16

They wont be alone forever

The human brings fertilized eggs (or eggs/sperm) and incubators with them. Their duty is to help the machines set up the colony, which might take some time, maybe months, maybe years, then activate the incubators und go to stasis again.

They will later wake up again to help raise and educate the children, maybe in intervals go to stasis again for years, to be able to give guidance to the colony over a longer period than a human livespan.

Why not two or more persons?

• maybe because the statis chamber is expensive and heavy, you really want to bring only one.
• more importantly, because it has shown that the colony setup is best done by lone ranger types, more people tend to bring unnecessary friction and conflict to the early phase.
• specifically, bringing a couple will often lead to them preferring their own children, which will lead to conflict later down the line.

Why not zero persons?

The AI cannot be trusted with raising human children on their own. There may be other tasks in the setup phase where human assistance is needed.