[Interstellar flight] Crew requirements

[wehaveaproblem]

Ok, I give up then. Maybe you're being trained by an alien. Or a computer. Or what if you somehow set up a program by which lions learnt at least some of their aircraft operating behaviours from other lions?

I think we are losing each other here. I don't believe lions in their current state could ever learn to fly a plane, they don't have the mental or physical capabilities.. they certainly don't have thumbs.

Now, if we genetically altered lions to be able to do so... well then they wouldn't be lions in the conventional sense any more. So what is considered natural to them is whatever capabilities we implant them with.

There is no evolution, between paleolithic humans and humans of today, it is just technological development.

Well here's the rub. I see technological evolution as an extension of biological evolution. I see it as the way humans are evolving past hunter gatherers.

Domesticated horses, cows and chickens do things their wild counterparts couldn't or didn't. That is domestication. Civilisation, can be regarded as "self-domestication". There is nothing wrong or evil about it, but rather the adoption of a lifestyle in a system that replaces the "native" behaviour of humans- which is that of a hunter gatherer society.

Domestication is an interesting one. But I would like some citation to your claim. My domesticated cats sleep, eat hunt and defecate... they would breed if they could.... and that is all their wild counterparts do. Yes, the context has changed, but the fundamental behaviour has not.

Humans are just animals. We may be very special animals, but we're still animals

100% agree.

 

[Wishbone]

Why is the reconnaissance a problem?
All you need is to send out a set of probes to the nearest stars.
These can be mostly fuel or ramscoops, and go quite fast, one way.

I don't see a lack of adequate computers by that time to do the rather basic "take all data measurable and beam it back home" task.
The brainpower stays at home, analysing the data and determining feasibility.

As for the unforeseen problems, the colony boat following the probe would have to take it's chances.

Data reduction is the problem (the farther out you are, the lower the throughput, and you'll be getting (mostly useless) information in terabytes). Delays of 20-30 years are the problem. Software updates are the problem.

Heck, the most significant (IMHO) reason to send scouts is testing the design of the ship. A human engineer will at least send out an emergency action message (oops, sorry - wrong forum)... emergency message with some info on the design flaw...

It is also important to note that by sending humans we save on redundancy (no need for super-duper self-repairing nano-robotic sensors and actuators).

The scout ship will not do exploration. The main mission is to decide on the degree of habitability of the target planet and safety of the route.

If you ask me, I'm not prepared to send a thousand or so people to death...

 

[T.Neo]

I think we are losing each other here. I don't believe lions in their current state could ever learn to fly a plane, they don't have the mental or physical capabilities.. they certainly don't have thumbs.

Now, if we genetically altered lions to be able to do so... well then they wouldn't be lions in the conventional sense any more. So what is considered natural to them is whatever capabilities we implant them with.

Obviously, it would not be a lion trying to fly a conventional aircraft. And it probably wouldn't be a lion flying the aircraft from takeoff to landing, either. In fact, it might not even be a real aircraft, rather just a simulation...

Tattoed fish have been altered by humans... they are not particularly natural.

Well here's the rub. I see technological evolution as an extension of biological evolution. I see it as the way humans are evolving past hunter gatherers.

Considering that it's not found in the scientific description of evolution, technological development isn't evolution in anything but a vague philosophical sense.

Also: I can take a modern human, and put them in a tribe with their paleolithic ancestors of 15 000 years ago. They're not any different from the other members of the tribe. I can take a member of that tribe into the modern world, and they're not any different from the other members of modern society...

Domestication is an interesting one. But I would like some citation to your claim. My domesticated cats sleep, eat hunt and defecate... they would breed if they could.... and that is all their wild counterparts do. Yes, the context has changed, but the fundamental behaviour has not.

Horses accept funny apes to ride on their backs? Cows congregate to drink from troughs positioned near wells/pumps?

Of course the behaviour has changed, even if some core concepts remain the same. Though I would regard activities such as eating, defecating, breeding and (potentially) hunting to be too general to be of note, unless they were somehow affected.

If you ask me, I'm not prepared to send a thousand or so people to death...

But you are prepared to send five, or ten people to their deaths?

Software updates and whatnot are why you have advanced software and hardware aboard the probe. Failure potential is why you have redundancy.

Communication problems, are why you could potentially have a laser system or something to that effect, that is more directed and not liable to some of the problems another such system might be.

The advantage with unmanned probes, is that they can be lower mass and even go faster, they don't have the added mass and complexity of needing to support hundreds of human passengers.

 

[Wishbone]

If there's a way to solve the habitability/safety question without sending out manned scouts, I'll be ready to dump this stage. The life support system mass is a burden, as is the requirement of the flight back. Redundancy is not a panacea, in-flight maintenance and repair are much better in this respect. How many missions have failed because of SEUs and latch-ups, or single erroneous commands sending the craft into a spin?

Re: software. Would it make sense to compile millions LOC that provide for all eventualities but will be tested in action only 20 years later?

 

[T.Neo]

Hence why you have redundant systems and computers... all in all, the mass would probably still be less than that of a manned vehicle.

If the trip is 40 years, what is a round trip? 80 years? That isn't terribly practical...

I would rather spend five times the price on five unmanned spacecraft than send a few of five people to their deaths. It's pretty silly to close out the potential for an altogether simpler spacecraft, saying that such technology cannot survive without people and thus giving up on engineering any problems to workarounds...

 

[wehaveaproblem]

Horses accept funny apes to ride on their backs? Cows congregate to drink from troughs positioned near wells/pumps?

Of course the behaviour has changed, even if some core concepts remain the same. Though I would regard activities such as eating, defecating, breeding and (potentially) hunting to be too general to be of note, unless they were somehow affected.

Cows congregating at a water source is about as natural as you can get, with regards to herd animal behaviour...
And if the horse can carry the load, then it is within it's natural bounds to do so. As it is within the human bounds to ride, then it is natural to work out how to do so... if it benefits, which it does. Arguably relationships with domesticated animals is somewhat symbiotic.
And I don't see how you can dismiss the fundamental activities of an animal as 'too general to be of note'. These activities are exactly what makes the animal the animal.

Tattooed fish are something new to me, I will have to check that out before I make a judgement.

 

[Wishbone]

Because of DoD funding we've seen great leaps in AI in the past ten years. Am beginning to realise that the gap between unmanned probes' capabilities and colonisation decision requirements can be closed without a manned mission. So here's what's needed:

a) universal roboengineer to repair the probe;
b) rad-hardened massively redundant supercomputer to reduce all the data;
c) mission AI that is smarter than HAL.

 

[T.Neo]

What horses carry loads on their back in nature? None. It is an unnatural activity, because, it never happens in nature. You can't get it simpler than that. They may be capable of it, but it isn't natural. Likewise, to use our close relatives as an example, do you see any other hominid riding another animal? No. We are capable of it, and a chimpanzee might be capable of it as well, but it isn't a natural behaviour.

The fundamental activities you mentioned are poor descriptors for a specific species, because such traits are pretty much held by almost every animal in existence. Saying that I eat, therefore I am human, is pretty bad, because by that description I might as well be every single heterotrophic organism at the same time, and they might as well all be human at the same time...

a) universal roboengineer to repair the probe;

Before we go into anything like roboengineers, we can first discuss physical redundancy, ruggedness, and fine tolerances to prevent some problems- essentially, similar to what is already done in spaceflight a lot.

A "universal roboengineer" would probably look more like Dextre than Robonaut, but either way it'd need highly advanced software to be able to effectively perform any inflight repair.

b) rad-hardened massively redundant supercomputer to reduce all the data;

Reduce the data? I'm confused... are aliens trying to flood the communications between the ship and Earth with lolcat animations?

Also, "rad-hardened massive supercomputer" does not sound so bad when you remember Moore's law... you could also probably run the mission software on something with equivalent power to a personal computer of today, provided the software was good enough.

c) mission AI that is smarter than HAL.

Determine "smarter than HAL". For one, it doesn't need to be anything like a movie robot... just a very clever extrapolation of software you might see in a Mars rover or Shuttle. Which might not be as interesting, but makes several orders of magnitude more sense.

 

[Artlav]

Manned probe takes 40 years, unmanned may take 10 for same cost or 20 for a hundredth of the cost.

You can solve redundancy by sending a lot of them, they don't need to be terribly smart, just good enough to pick out wandering stars, figure out their masses, do orbital manoeuvres, and record observed data. Also, must know how to aim a message laser at Earth.

It's a starship, so it's a good assumption that it would have quite enough Dv to approach and leave many planets.

I don't see anything needing inventiveness here, and everything else is within computer capabilities by modern understanding.

Downlink can be a problem.

Is something like a solar sail, miles across with variable surface transparency/reflectivity possible?
It's angled to reflect and focus star's light towards Earth, and flicked on/off to send data.

 

[wehaveaproblem]

What horses carry loads on their back in nature? None. It is an unnatural activity, because, it never happens in nature. You can't get it simpler than that. They may be capable of it, but it isn't natural. Likewise, to use our close relatives as an example, do you see any other hominid riding another animal? No. We are capable of it, and a chimpanzee might be capable of it as well, but it isn't a natural behaviour.

The fundamental activities you mentioned are poor descriptors for a specific species, because such traits are pretty much held by almost every animal in existence. Saying that I eat, therefore I am human, is pretty bad, because by that description I might as well be every single heterotrophic organism at the same time, and they might as well all be human at the same time...

It never happens in nature? But we are nature, we do it, so it happens. Chimps can't, they don't have the mental faculties to use another animal as a tool like that... Otherwise they probably would.. but then they would probably be further evolved... aka human(ish).
I didn't say I eat therefore I am human, you paraphrase me badly again. I said that those activities are the core activities of an animal, so whether an animal searches out its water from a river or a bowl is irrelevant. My cats do what wild cats do, they just do it in a different environment.

But again, I fear our debate is beginning to go in circles, so perhaps we should call it a difference of opinion and be done with it.

 

[T.Neo]

Ah yes, we can agree on something- we are nature. It is very easy to think, that we are somehow seperate from it.

Nevertheless, that's not my point. Which is that domesticated organisms (including "domesticated" humans) perform behaviours their "wild" counterparts do not. A cat might search out water from a river or bowl just the same, but it can still exhibit behaviours it's wild cousins do not, and that's a fact. Stemming already from the fact that organisms in different environments will exhibit different behaviour.

Humans, and other animals, might be natural, but we can still engage in unnatural behaviours. And a chimpanzee should have enough of a "mental faculty" to ride a horse... it's just that they don't have the imperitive to. Then again, neither do many humans...

A previous forest converted into a city, or a fish branded with "I LUV U" are not natural. Just because those phenomena were created by natural organisms, does not mean they are natural themselves. In essence, it's a facet of the "lumping vs. splitting" argument- either you lump everything together in "natural", or you split things into "natural" and "unnatural". If everything is grouped together, there is about as much meaning to "natural" as there is to "unnatural" in that case (i.e. they're both equally unapplicable).

 

[Wishbone]

Re: solar reflectors - not sure if we can do gossamer structures of this scale. Haven't we discussed the "engine X-ray modulation" approach before?

Re: universal roboengineers and physical redundancy/ruggedness. Depends on how successful we are at eliminating rotating parts, which are by far the largest source of uncertainty and risk in longer flights (life without CMGs can be tough). And yes, the autonomous troubleshooting AI for the Mega-Dextre is going to be quite a challenge. Need at least two of them to repair each other though
Even at low sub-c velocities, stray grains will do great damage. What if they hit a thruster? The Mega-Dextres have to cope with such cases, as well as (say) changing sensor arrays.

Re: data reduction. We do know where we want to go (nearest stars with planets). We don't know whether any of the planets are habitable and whether there is/was life on habitable ones, and if so, whether it is/was intelligent. It would take some mapping to get a bit of data to help solve the problem by pinpointing spots for landers to explore. This is terabytes of images, no way we can transmit them over the distance of 10-20 ly, processing on the spot seems to be the only option (possibly with downlinking a handful of the key evidence).

Re: smartness definition. Ability to re-plan the mission, to re-configure the spacecraft around known or suspected failures, to schedule and execute maintenance/repair, to process tons of data for outliers/patterns (own telemetry and images). For some of these problems we have only exponential complexity algorithms.

 

[T.Neo]

Well, the ship will need armor, such as whipple shields for example. It is extra mass but far lower complexity than having to replace entire components.

You raise a very good point with picking interesting data... but that should not be too hard. We can already determine whether planets are (in all likelihood) habitable from back home, selecting data to send back home should not be problematic- simple software can already pick through the boring stuff, and note anything anomalous.

Current software/hardware can already do some of those tasks... considering some of the abilities of current spacecraft (which run on hardware which is quite poor by even modern standards), I can imagine that an interstellar spacecraft would have quite a capable computer system able to do things such as replan or reconfigure the mission in light of failures/incorrect data.

 

[Wishbone]

The basic premise of non-stasis interstellar flight (procreation en route) seems flawed now: http://www.independent.co.uk/news/s...ill-stop-humans-colonising-space-2213861.html.

This assumes that shielding stays the same as on modern manned spacecraft. Without going into calculations, it looks like only colony ships will be able to afford better shielding that would reduce radiation to Earth levels.

 

[T.Neo]

That's because modern manned spacecraft only have rudimentary shielding. Manned spacecraft have (so far) either been limited to LEO, where the magnetosphere still provides protection against the solar wind, or have gone outside the magnetosphere for only a short duration (limiting cumulative exposure and the probability of being caught in an SPE). They don't need such extensive shielding.

Again a study, that even a moron who has gained all his knowledge from rudimentary internet research could be able to refute. If you are using only the amount of shielding that is placed on conventional spacecraft, you are being extremely unwise, space pregnancy or not. And on top of that, it is rather silly suggesting concieving a baby in transit to Mars, as the microgravity environment itself will be far more harmful than radiation exposure, and the rigors of spaceflight (particularly takeoff and landing) are definitely not a good environment in which to place a pregnant woman. Nevertheless, radiation exposure in space itself is still relevant to colonies situated in space, or interstellar generation ships (presumably in an environment with properly simulated artificial gravity).

Radiation exposure is just as important for those in stasis as it is for those who are awake... people in suspended animation are still exposed to radiation, and if their biological processes are stopped, they're actually in a worse off position because their bodies can't repair radiation damage.

On an interstellar spacecraft far from a star, stellar ionising radiation will be minimal, although cosmic rays will remain present. However, travel at any considerable velocity, and the interstellar medium- primarily hydrogen atoms- will become high energy particle radiation in it's own right. The advantage to this is that it comes from one direction, so you "just" need a big shield on the front of the ship as a sort of "cow-catcher" for interstellar particles.

A sleeper ship will definitely be able to afford more shielding than a generation ship mass wise, because there are very large mass savings involved when you don't need to support multiple generations onboard. Thus those in stasis might be more effectively shielded, and thus be healthier at the end of the journey.

If magnetic radiation shielding can be used, then the prospects become much better, both when dealing with stellar radiation and interstellar hydrogen.

The ramscoop on a Bussard Ramjet actually very usefully doubles as this, so on Artlav's Hius the problem is already solved.