In the near future an ancient, derelict spacecraft or space station has been discovered orbiting Barnard's Star, 6 light years from Earth.

Why would Earth send a manned mission to Barnard's Star to explore the artifact -- increasing the complexity, expense, and risk of the project -- rather than probes or AI robots?

(My thinking is the story wouldn't be as engaging if the main characters are robot probes, although I'm open to suggestions.)

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    $\begingroup$ The English mountaineer George Mallory was once asked by a news reporter why he wanted to risk his life trying to climb Mount Everest. Mallory replied, "Because it's there". He died in the attempt. Just replace Mount Everest with Barnard's Star. $\endgroup$
    – AlexP
    May 31 at 18:04
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    $\begingroup$ @AlexP "Just because" is fine enough reasoning for a small group of people, but I don't see nations-worth of economic output being poured into the most complex technological feat ever accomplished "for fun". Mallory's response would have been obscenely flippant if summiting Everest required a good chunk of the planet's GDP as well as generations of his descendants' certain deaths in the cold vacuum of space - hard to justifying doing that "just because". $\endgroup$ May 31 at 18:17
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    $\begingroup$ One could say that the Moon Shot was a frivolous endeavor. There were very few reasons to go to the moon at the time past proving we could. $\endgroup$
    – Gillgamesh
    May 31 at 18:35
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    $\begingroup$ @NuclearHoagie To quote one of the most inspirational speeches ever given on this topic, "We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard". It is solving problems that allowed our species to rise to pre-eminence on this world, it is solving problems that gives us motivation in our everyday lives, it is solving problems that drive us forward and allow us to control our very evolution. And the more difficult the problem, for many the more reason to attempt solving it. $\endgroup$
    – Ian Kemp
    Jun 1 at 8:52
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    $\begingroup$ On a side note, Wall-E shows you can make an engaging story with a couple of robot probes. $\endgroup$ Jun 1 at 13:14

17 Answers 17


It is proof of life outside earth, and technological life at that. The potential discoveries boggle imagination. It is the single most important discovery in the history of the world. Likewise this is will be the most important expedition in history and likely the most expensive. The moon landing is a pittance by comparison. The GDP of a large country is a small price to pay. This will be a collective effort of hundreds of countries if only to make sure one country cannot monopolize any discovery. There are thousands of experts who would volunteer for the trip even if it was only one way.

Probes are basically useless at those distances, especially exploring something that is largely unknown. that's 12 years of lag for every decision. the probe will have decayed into uselessness before it can do much. Human explorers will probably bring probes with them, a few micro-second delay allows for remote control 12 years does not. If only to make sure the environment is not toxic.

AI is also useless, AI are really bad at highly unique, never before considered situations and I can't think of a better example of one of those. The robot could be rendered completely useless or worse destructive by a single false assumption. Humans can problem solve in unique situations, humans can make new tools and make decisions as the situation changes drastically, as the very context of the decision changes.

  • $\begingroup$ Assuming we won't be traveling at the speed of light, the trip may take say 50 years. In those 50 years we may develop technology that could catch up and overtake the initial mission... An interesting dynamic to contend with in terms of an optimal strategy. $\endgroup$ Jun 2 at 6:02
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    $\begingroup$ pity that our capitalistic nature while it pioneered inventions, it also our bane of existence since every surplus greed is simply a wall to further our civilization $\endgroup$ Jun 2 at 6:06
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    $\begingroup$ @encryptoferia "capitalistic nature" is an oxymoron. Just because you were raised in a world where it dominates doesn't mean it's natural. $\endgroup$
    – Hobbamok
    Jun 2 at 10:06
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    $\begingroup$ @LamarLatrell, I believe that's called the "waiting problem". $\endgroup$ Jun 2 at 20:45
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    $\begingroup$ @flox worse AI are very VERY susceptible to bias, more so than even humans which is impressive, and this is exactly the wrong situation for bias to be helpful, bias towards human environments, manufacturing, and society is going to make AI VERY error prone, because an alien ship may not conform to any of those biases. To put it another way, AI still can't play Calvin ball. $\endgroup$
    – John
    Jun 3 at 11:40

Because there is a 12 year decision lag with remotes

Autonomous robotics are fine and well when you know exactly where to go and exactly what to do.

Introduce any kind of dynamics to a situation, and you are [crap] out of luck trying to get anything done, as there is a 6 + 6 years delay from the remote seeing something, and then receiving any orders on how to act on it.

All you need to do to justify sending people there is that the first remotes see that the situation about this derelict is in any way dynamic, maybe it has a chaotic orbit, maybe it is difficult to explore, maybe there are more of them, maybe its orbit is about to decay and the derelict will be lost unless we hurry there and examine it.

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    $\begingroup$ This is especially true when you consider a hugely open-ended mission like "explore a derelict". When we send a rover to Mars, there's only so much it can do - drive around, probe rocks, take samples - but it's still complex enough that human decision-making is preferred. This mission is many orders of magnitude more complex. $\endgroup$
    – Cadence
    May 31 at 22:11

(Bouncing off of Gillgamesh's answer)

One of those reasons why probes are not enough is because the robotic mission was a flyby mission, a la Breakthrough Starshot. Actually decelerating from high fractions of c doubles the delta-v and adds an OOM to mission complexity at least. The probes dash through the system at cruise velocity and return enough grainy images and produce enough intrigue to warrant a manned exploration.

Why not send robots next? Trained humans with technical expertise are the best robots to send. The job can't be entrusted to software to anyone's satisfaction.


Assuming no FTL, a 1 way travel time of minimum 6 years. Asking for volunteers for this mission, you would still have hundreds of applicants. That is just the brighter side of the often dark human nature.

However realistically, I would immagin, unmanned probes would be sent first, to be followed by humans. No reason it can't be written into a story, that probes were sent but didn't get all the answers for a variety of reasons.

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    $\begingroup$ "No reason it can't be written into a story, that probes were sent but didn't get all the answers for a variety of reasons." => because probes singularly lack imagination, and assuming no FTL, it takes 6 years to get their signal, and 6 years to send a command back... Probes are nigh useless in this context. The only reason to send probes is to have them gather data that the upcoming manned mission will be able to read during their trip, and if you're smart you may as well send some further material for the upcoming mission to use -- if due to weight limits they can't bring it with them. $\endgroup$ Jun 1 at 7:53
  • $\begingroup$ @MatthieuM. see, supplying a manned mission with no less than 12 YEARS of food would require so much effort that adding a couple of advanced drones won't put a dent. $\endgroup$
    – Vesper
    Jun 1 at 15:01
  • $\begingroup$ @Vesper: You need to grow the food on the way; I was more thinking "spare" material capsules to resupply. And honestly? We don't have the capabilities -- today -- for advanced drones, and I don't see anything like Blade Runner's replicants anytime soon. $\endgroup$ Jun 1 at 15:28
  • $\begingroup$ There is a thousand ways to handle an manned/unmanned mission. Multiplied a thousand more because we don't know what kind of tech level we are dealing with. $\endgroup$
    – Gillgamesh
    Jun 1 at 18:45
  • $\begingroup$ This doesn't really address the question and should be a comment. $\endgroup$ Jun 2 at 9:06

Inadequate remote intelligence

Mars is only three minutes away. Getting data, reviewing it, and deciding what the rovers will be doing tomorrow is just an all-nighter.

Now imagine how that would work with a six-year delay. We could probably equip a drone with a really big telescope and program it to look for planets when it gets there. It could do a fly-by of this thing and take pictures. You could use planets (that may or may not exist in our world) to do aerobraking and reverse-slingshot maneuvers to slow down enough to stay in the system. Anything at all beyond that would be way beyond what we could program a machine to perform.

The real problem is the question-and-answer cycle. A machine could navigate a logic tree, make observations, maybe even collect samples and identify testing priorities. What they couldn't do is realize that the alien tech is trying to communicate with it, and attempt to come up with a mutual protocol. It couldn't realize that the shape of the space station was analogous to one of the nearby planetary systems. It couldn't formulate an alternative test when incomprehensible information comes out of the spectrograph.

Andy Weir does a great job describing this situation in Project Hail Mary. In his case, it was a team of three, and only one survived the cold sleep. I recommend it, by the way.

Alternately: send a billionaire

They don't need a real reason, they just have to have a big enough excuse. Sometimes their ego is enough excuse. These are people with enough money to fund their own mission, so expense wouldn't matter. And maybe he just wanted to keep the alien tech to himself.


Humans are cheap

The ship needs to carry around 100 tons of equipment to examine the station anyway, humans can be stored in stasis pods that just weigh 100 kilos or so. Carrying a couple tons of humans means you have flexible and intelligent minds to adapt to the situation and doesn't notably strain the engine more.

The spaceship isn't subject to the rocket equation, they have fusion power which allows easy fast travel.

  • $\begingroup$ "Priority one : Insure return of organism for analysis. All other considerations secondary. Crew expendable." $\endgroup$
    – Mazura
    Jun 1 at 22:52
  • $\begingroup$ Are they though? You need to provide food, water, a toilet, oxygen, a recycling system, medicine, ... $\endgroup$ Jun 2 at 9:08
  • $\begingroup$ Do you though? You could just send a fabricator and grab an asteroid and build them on site. $\endgroup$
    – Nepene Nep
    Jun 2 at 11:35
  • $\begingroup$ Why they are though? Cryopods that they only built four of and used two mirrors. $\endgroup$
    – Mazura
    Jun 2 at 19:47

It's what we do

Of course it makes no sense to risk life and limb going to the Moon, Mars, or the next star over. We have probes that make just as good of a job, if not better. And at worst if one fails, it only costs money, whereas a human life is priceless.

But we can't be content with that.

Humanity has a thirst for exploration and knowledge. It is one of the constants throughout human history. We went to the end of land to see what was there. We launched ships to see what was on the other side the ocean. We climbed the tallest mountains. We dove into the deepest trenches. We sent people onto the Moon. We're gearing up to go to Mars.

There is no practical purpose to any of this. Not really. But it's there. We can see it. We can almost touch it. It doesn't matter how challenging it is. It doesn't matter whether it's necessary or not. Not going ourselves isn't an option. We can send probes at the same time, or before. But we're going.


I am actually fairly certain that sending a manned mission or at least partially manned mission would be a necessity.

You said it is near future, so I will assume that AIs are still being taught as they are now, by being exposed to ever growing datasets and their ability to work properly depends on the situation they encounter to be at least similar to a situation that has been included in the dataset.

However this mission is not about dealing with the expected, it is impossible to prepare AI for tasks that are not yet known yet. You need human there to make decisions on how to proceed, when obvious solution is not available. AIs will be present, and it is quite possible, it will be able to accomplish all a human could, but it is more then likely when a scenario is presented, that AI just doesn't have data to fall back on, at which point human crew will be required to analyze the data available and make a decision on how to proceed.

Unlike AI's this decision may be "wrong" but human crew would be allowed to make the call in these situations.


FOMO, and AI is not us.

Many answers here focus on AI being inadequate or underdeveloped for the task: I disagree. AI can likely do everything a human can do - potentially better. I have no doubt an AI can react to changing circumstances, can investigate thoroughly both the scientific and cultural aspects of the space station, and provide a comprehensive report back to Earth in 12 years time.

But the big question then is: Why send AI instead of us?

For humans, there is a very large psychological motivation: FOMO - the Fear Of Missing Out.

This is a drive within us to make sure WE are the first, WE are the ones there to see it, to take advantage of it or to be the first to make contact with a new Alien race, because if we did not we would 'not be there' - and an AI is not 'us'.

There is also the danger that sending an AI on a First Contact situation of such magnitude may be a signal to any alien civilisation that the AI is our culture, not a human culture. The aliens may shower benefits onto the AI, and not give them to us. Aliens might even see us as brutal oppressors of the AI, who can delete the AI's at any time, who bend AI's to their will without conscience - they could take pity on AI and give them the ability to conquer us.

Put it simply: AI cannot be entrusted with an issue of this importance because they are not us. Even if humans are sent that are or may become inherently untrustworthy, they are at least us, and representatives of humanity on such a momentous occasion.


A Frame challenge:

An ancient derelict spaceship or space station orbiting Bernard's star six light years away would have to be immense to be detected from our solar system "in the near future".

Kepler-37b is the smallest known exoplanet with a radius of 0.296 that of Earth, or about 1,885 kilometers.

An extrasolar planetesimal known as WD 1145+017 b has a radius about 0.15 that of Earth, or about 955 kilometers.

SDSS J1228+1040 b is an extrasolar planetesimal with a radius of about 0.0101 that of Earth, or about 65 kilometers.


Those are the smallest dimensions of known objects orbiting other stars.

And possibly some of them are not as firmly established as claimed by the list.

And experts of the most advanced planned instruments which can be used for detecting exoplanets might be sable to say whether any planned instruments could detect objects as small as, for example, 10 kilometers in diameter, and when those instruments are planned to come on line.

I suspect that extreme lucky circumstances enabled the detection of the smallest know objects in other star systems. And an extremely advanced instrument which goes online 20 years in the future might be used for a decade or two before it makes a very lucky discovery of an object only about ten kilometers in diameter.

And I have to wonder how the artificial nature of tiny objects detected in other solar systems will be discovered.

If images of an extrasolar object are taken, and also its spectrum, and the spectrum in radially different in certain ways from that of the star, it might be deduced that the object is made of polished metal, or of some synthetic compound of great strength.

Less than thirty planets of other stars have been detected or suspected by direct imaging of those planets. The smallest of those which have estimated sizes, Candidate 1 orbiting Alpha Centauri A, has a radius of about 0.459 that of Jupiter or about 30,685 kilometers, or 4.8 times the radius of Earth.

So instruments will have to vastly improve before an object the size of an imperial star destroyer in Star Wars can be detected. And improve even more before before such an object can be determined to be artificial.

So I have my doubts about the artifact being detected, and a mission sent to Barnard's Star, in the near future.

Possibly the main character can be the world's most famous scientist, or the world's most famous astronaut, who dies suddenly and their corpse is frozen. They are brought back to life by advanced science centuries in the future, at about the time that the artifact is discovered and the expedition is planned. And because future people are much less bold and adventurous than 21st century people, and because the main character is a famous person from the past, they are selected to go on the expedition.

Maybe only recently revived people frozen centuries earlier will volunteer to go on the expedition.

  • $\begingroup$ Node that SDSS J1228+1040 b is approximately 410 light years away. If we can detect a 65 km object that far away, we won't have a problem detecting a much smaller object only 6 light years away $\endgroup$
    – Seggan
    Jun 1 at 16:51
  • $\begingroup$ I guess those smaller objects would be either discovered by the eclipse method (like most exoplanets), or by them actively sending out radiation in our direction. Or maybe a prior sent probe found it on the way through that system, but couldn't change course (possibly due to missing fuel, or just the communication lag). $\endgroup$ Jun 1 at 23:50
  • $\begingroup$ You can always argue it was detected in a fly-by mission, not from a telescope back from earth. $\endgroup$ Jun 2 at 9:09

Frame challenge: Public choice theory

There is no problem. You don't need the nation to benefit, just a few select people.

Maybe the chief contractor had a cost plus contract written by a foolish (or corrupt) public servant and just acted in his own interest, while the politicians involved had every reason to deny any money was wasted. Win-win all around, except for the plebs that paid taxes. And even they got some feel-goods.

Press releases make many of the arguments you see in other answers here; after all, the comms team have to fill up their timesheet too, so why not?

Individuals in institutions have different incentives to their institutions as a whole. Managers want bigger budgets. Employees want more pay and fun jobs. Senior executives want stock prices to be high when they cash in their stocks. Politicians want to be reelected. Contractors want contract renewals. Aeronautical and defence contracting is absolutely rife with it. NASA has had plenty of it in real life. That's not even considering egos and libidos and test pilots' need for speed.

You can make the individuals involved anything from dedicated individuals faced with accidentally perverse incentives through to completely venal and corrupt, or an intermediate position, like the example earlier.


Testing technology for stellar travel

The mission is an experiment of testing technological capabilities that are necessary for travels to further stars.

In a similar way we have the Mars-500 mission or biosphere experiment where the "astronauts" don't even leave earth. Or compare to the space stations in orbit around earth which will some day be overtaken by stations on the moon and Mars (and eventually another star).

The earliest space travelling of humans to other stars can be expected to be to close neighbouring stars that are not specifically interesting except for being another milestone on the way towards a bigger goal.

Stepping stone for further travels

The travel to a nearby star can also be a stepping stone for further travels. As part of colonization of further places.

When traveling at 10% of the speed of light, it will take 60 years to reach Barnard's star. It will be difficult for a human to travel further and such a long distance space travel may take several generations.

In order to reach further we will need to colonize the roads along which we travel in a similar way as people of the past used to settle along trading roads just for the sake of the road. A name for the ship/settlement could be 'cape Barnard'.

Human alien origins

In the near future an ancient, derelict spacecraft or space station has been discovered

The background of this discovery is not very clear. Is it an alien species that discovers Earth, or are it humans from earth that discover the space station from Earth? In the latter case, why would humans 'discover' the station. Is it a completely unknown station from an unknown past, or is it a space station whose existence is known but got 'lost' and has been rediscovered?

In the case of an unknown station it could be a station that is of alien origin from which humans descent. The place were Adam and Eve are born and where sent to Earth via the comet that killed the dinosaurs. (In this story line one needs to figure out a reason why the station did not send out radio signals and didn't got discovered before; possibly it is because it closed when Adam and Eve left the station)

So in this case Earth is not the origin of the space station, but instead earth is the destiny.


Kennedy already answered that one:

We set sail on this new sea because there is new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people. For space science, like nuclear science and all technology, has no conscience of its own. Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. I do not say that we should or will go unprotected against the hostile misuse of space any more than we go unprotected against the hostile use of land or sea, but I do say that space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made in extending his writ around this globe of ours.

There is no strife, no prejudice, no national conflict in outer space as yet. Its hazards are hostile to us all. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say, the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas?

We choose to go to the Moon. We choose to go to the Moon... We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too.


The AI controlled probes have found tantalizing evidence of alien script and user interfaces. AI is used to mitigate the time lag. The AIs have become erratic after an interaction with some kind of field evidenced by telemetry.


it's a good way to get rid of "undesirables". Not too dissimilar to the way the British used Australia as a prison colony during the age of sail, and France their South American colonies, and Russia sent them to Siberia, China to their high desert interior, a space faring civilisation could well use one way missions to a star with a planet that's suspected of being able to support human life as a cheap and convenient way to prepare the land for the eventual arrival of valued settlers, by which time the prisoners will likely be mostly dead and if not all too happy to be given a new life as indentured servants just because it's slightly less dreadful than the early settler experience they had before.

It doesn't always work out that way, but it's historically been a recurring way of thinking to use prisoners or people otherwise considered "disposable" for such things.



Recently we've sent multiple landers to the Moon that have failed. Unanticipated failures in hardware or conditions that triggered hardware failure modes revealed flaws or inadequacy of the programming. A human could have tried to evaluate the fault and maybe compensated but the automation couldn't. For years of communication delay it's very likely someone would decide there's just too many events that are impossible to anticipate in programming. If you have the tech to send a human but not FTL communication or strong AI it provides a LOT of intelligence.


We were already going.

(Depending on how near this near future is)

The probe that detected the orbiting derelict is just one of a wave of advance probes that we sent out in every direction. We were already following up with manned missions, each in craft designed to survive and operate on a nomadic basis. We already have a station at the L-4 and L-5 points in Saturn's orbit, whose purpose is to further develop this capacity.

The only real effect of discovery of the alien derelict is that Barnard's Star moved up on the list of places we want to go, but we were already going there anyway.

(A bit of AI + Von Neumann machine hand-waving is in order, to provide the technological and economic basis for this near-future state of affairs.)


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