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[Aseaheru]

or mars...
or titan...
or go see if coyote is habitable... well, once we get some higher speed things that is. it is around... 4.1 lightyears?

[Starver]

or mars...
or titan...
or go see if coyote is habitable... well, once we get some higher speed things that is. it is around... 4.1 lightyears?

Get to a high-enough speed and it'll seem like no time at all!!!

Of course each planetside base we go for (even assuming for now that it's not even extra-Solar) will be a balance of why we need to be there and what we need to be there.  (For the former, resources/etc, or at least exploration to determine what there is we might exploit.  For the latter, there's maintaining atmosphere, heating/cooling as appropriate, the difficulty of descending/ascending that particular gravity well as needed.)

But apart from being fairly constant apart from some variations regarding Solar distance and the influence of the moon's 'parent' body, you've got yet another set of choices for the orbital locations.  Balance the lack of need to defeat a gravity well (or at least an entire one) to get to other places with the dangers discussed about radiation/impact/etc and the lack (until and unless asteroids are brought into the equation) 'easily' available materials for continuing development.

I rather tend to think that (given the choice) I'd choose a planetary surface (or that of a decent sized moon, Luna or otherwise[1]) where possible (and happier with a practical Venusian surface base than a "cloud city" one), rather than an orbital habitat.  But it's all hypothetical, and once (if!) the opportunity came up there'd probably be whole new set of updated considerations to be made, commitments to fulfil and plenty of unforeseen circumstances to endure after signing up in the first place...

And, besides, this isn't about me, it's about humans in general.  There'd be all sorts and there'd be all sorts of positions needing manning.  Once we get off our behinds and get out of the nest more seriously than we're doing now.  (Not that it's not serious, but I'd like to see it being even more so...  Ideally before there's a compulsion to and certainly before we end up losing the ability to even try!  Let's get the eggs and baskets sorted out quickly.  And, yes, there will be some omelettes made along the way, I'm sure.)


[1] A large enough one.  Let's arbitrarily say that as Mercury has a surface gravity of 0.38g and Eris (prev. "Xena") appears to be 0.09-ish that of Earth, anything with at least 1/10th g.  (Despite some earlier comments, it'd be easier to implement centrifuges (for at least theraputic use, if not for constant living conditions) in free-floating stations than in ones sat on a bedrock surface.)  So that gives us a half-dozen non-terrestrial moons in our system to consider[2], by my reading, although I'd be loathed to rule out Pluto itself, for nostalgic reasons, and by including that might mean I would need to add at least Eris to that list...

[2] Triton, Europa (unless the Monolith tells us otherwise!), Io, Callisto, Titan and Ganymede.  (One moon of Neptune, one of Saturn and four of Jupiter.  If you're counting.  I suppose I could let Titania scrape in to not leave Uranus go unduly unrepresented by a near-human presence.)

[PanH]

or mars...
or titan...
or go see if coyote is habitable... well, once we get some higher speed things that is. it is around... 4.1 lightyears?

Get to a high-enough speed and it'll seem like no time at all!!!

Well, even with light speed (unrealistic), that would still be at least 4 years to get there (unmanned mission). If you want to colonize it, you'd need an autonomous (food, water, energy) ship, which could probably be used as the start of the colony.

[Aseaheru]

if we manage to get to a portion of light speed, and have suspended animation...
whats 200 years while asleep anyways?

[andrea]

and if we get close enough to c, relativistic effects. the trip will be shorter. at least for astronauts.

[vadia]

if we manage to get to a portion of light speed, and have suspended animation...
whats 200 years while asleep anyways?

If the machines function for an average of 150 it's a problem.

To make a significant time difference one has to go at least .9 the speed of light (at which point a single dust particle could be catastrophic)  [the force of 1 dust particle would be about .1 kg/second with 10 micrometers diameter.  so a pressure standpoint that's 10,000 km/s/cm]

Even if you could get to .9c much of the trip would be acceleration (counting deceleration as acceleration) so much of that time will not be effected by time dilation anyway.

I'd think that before leaving one would seriously need to send a probe.

[10ebbor10]

Just to note. Nasa scientists think an average lifetime of 20 years is a good estimate for any space probe without maintenance.

And just as a note, relativistic effects won't have much effect on the exploration of nearby orbital bodies, unless we suddenly get a higharceleration drive. (Alcubierre warp drive, for example).

(and happier with a practical Venusian surface base than a "cloud city" one),

Unless we find a way to obliterate 99% of a planets athmosphere, we ain't having no Surface bases on Venus. Why does nobody like the floating base thingies.

[Aseaheru]

probaly the same reason why almost nobody likes solar powered cargo airships, which exist.
helios airships.

[vadia]

Just to note. Nasa scientists think an average lifetime of 20 years is a good estimate for any space probe without maintenance.

And just as a note, relativistic effects won't have much effect on the exploration of nearby orbital bodies, unless we suddenly get a higharceleration drive. (Alcubierre warp drive, for example).

(and happier with a practical Venusian surface base than a "cloud city" one),

Unless we find a way to obliterate 99% of a planets athmosphere, we ain't having no Surface bases on Venus. Why does nobody like the floating base thingies.

So when we can get a probe that would last about 40 years and go .1c (or 80 and .05c etc. within reason) it's time to send it to the nearest planet to see what it's like?
By the time we have info we'll have the ability to make a manned mission.

[PanH]

Just to note. Nasa scientists think an average lifetime of 20 years is a good estimate for any space probe without maintenance.

This. Making a autonomous self repairing space ship is extremely complex.
For example, we can't produce energy for this time. We wouldn't be near suns, so solar wouldn't work enough, and we can't make a 200 years nuclear reactor. The ship will also slowly fall apart. I've yet to see a 200 years old skyscraper (or would we send pyramids in space ?) and it's on Earth.

Why does nobody like the floating base thingies.

Because it's easier to settle on solid ground, like Mars.

[vadia]

Just to note. Nasa scientists think an average lifetime of 20 years is a good estimate for any space probe without maintenance.

This. Making a autonomous self repairing space ship is extremely complex.
For example, we can't produce energy for this time. We wouldn't be near suns, so solar wouldn't work enough, and we can't make a 200 years nuclear reactor. The ship will also slowly fall apart. I've yet to see a 200 years old skyscraper (or would we send pyramids in space ?) and it's on Earth.

Why does nobody like the floating base thingies.

Because it's easier to settle on solid ground, like Mars.

assuming less than relativistic speeds there will be MUCH less wear and tear on ships in the middle of absolutely nowhere. 

Not that I'd volunteer anybody's life to cryodeath.

[10ebbor10]

Let's just talk about circuitry. Are there any computers that have survived more than 20 years without maintenance? Probably not. There has to be a lot of redundancy, and yet it can't use to much energy, or too few(Freezing is dangerous).

[GreatWyrmGold]

Effeciency losses do add up though. Also, I made some calculations once for orbital power plants, and they don't ever come out energy efficient. Not with current technology. You'd need hyperefficient pannels (60% or more), hyperlightweight pannels, and hyperefficient transmission. Remember that the transmission calls for 1km diameter recievers.

I'd be interested to see your math.

Well, let's see. Normal solar pannels weight 20 kg per kilowatt production. Expected lifetime is less than a decade. As such, a 4 GigaWatt station would weight 80.000 metric tonnes. Just solar pannels alone, no supporting structure or anything at all. Assuming we can dump that in LEo, which we can't, and we do it with cheapest, most efficient heavy load rocket (Falcon Heavy (in development) at the moment). We still need at least 1509 rockets. Each costing 125 million dollars. Coming up at 188.625 billion dollars total. (Launchcost of panels only)  While that's not energy efficiency; I think I made my point.
Actually, probably not.
-Energy produced: 4GW*85%(transmission losses)* 10 years = 1072224 terrajoules
-Energy used: Is hard to find, because I only get thrust, not joules. So let's just go for economical viability then. Energy cost about 40 euro per Megawatt hour. Meaning that your solar pannel nets you 1191,360  million dollars

And there's another idea for my science fiction down the drain.
...Unless we make a space elevator first?

Well, all that water has to be put in orbit.

You don't understand how much water this is. Since we've been talking about mile-wide station, let us imagine one 1km across, in a ribbon 50 m wide and 5 m high. That's around 3 km of circumpherence, 150 000 sq. m of surface. If you want to have a 5m wall of water all around, you'd need twice that plus some stuff for the 6 m of wall, so around 2*150000*5+2*5*3000*5=1.650.000 cubic meters of water. That's 1.650.000 tons you have to pu in orbit. And why on earth would you need over 1.5 billion liters of water?

You're taking me far too seriously.
...And that number might not be too crazy. Two sources I found suggested water useage of ~60 gallons per person or ~400 gallons per family. Assuming a family of 2 parents and 2 children (to account for households with more children and fewer parents), a very rough but conservative answer of 75 gallons per person per day. That's around 300 liters. Assuming that half of the water is not used for everyday household purposes, and that the water recycling techniques can only recycle 1/10 of the total water supply per day, that's 6,000 liters or so needed in storage per person, so it would...um...never mind. I'm too proud of this math to discard it, darn it!

Modern day Recycling systems have 99% efficiency.

It's not the efficiency, it's how much can be recycled a day.
Which, of course, depends on how much machinery you use.
Of course, even with my estimates you'd need around a quarter million people in that kilometer-wide disk to need that much water.

As for cosmic rays. They're (mostly) composed of very high energy particles. And

Of primary cosmic rays, about 99% are the nuclei (stripped of their electron shells) of well-known atoms, and about 1% are solitary electrons (similar to beta particles). Of the nuclei, about 90% are simple protons, i. e. hydrogen nuclei; 9% are helium nuclei or alpha particles, and 1% are the nuclei of heavier elements

All these are sharged particles. Meaning that you can use a magnetic shield to deflect them.
Still need to worry about X-rays and gamma rays and stuff though.

Two things.
1. How good are we at creating such magnetic shields in an energy-efficient manner?
2. Aren't X- and Gamma rays sorta deadly? I'd imagine that, long-term, that much exposure would give you about the same chance of survival as kicking Bruce Banner in the shin and then insulting him a lot.

Still, given the massive logistic hurdle of getting those space station up and shielded. Why don't we just colonize the friggin moon?

Because someone argued that we could eventually all move to space-based habitats, nevermind the cost or that every benefit of space stations can be achieved planetside.

if we manage to get to a portion of light speed, and have suspended animation...
whats 200 years while asleep anyways?

A one-way trip. Generation ships are probably more practical.
Relatively speaking.

Let's just talk about circuitry. Are there any computers that have survived more than 20 years without maintenance? Probably not. There has to be a lot of redundancy, and yet it can't use to much energy, or too few(Freezing is dangerous).

Of course, most computers haven't been around since before 1993.
...Not that there's a lot of computers from pre-1993 that still function, but that might be as much from changing technology as anything. On that note, the toughest computers probably include some of the newest.
I'm going to stop and leave this to someone who knows what they're talking about before I embarrass myself more.

[Starver]

or go see if coyote is habitable... well, once we get some higher speed things that is. it is around... 4.1 lightyears?

Get to a high-enough speed and it'll seem like no time at all!!!

Well, even with light speed (unrealistic), that would still be at least 4 years to get there

...but seem like an instant.

(Snipped "unmanned mission", because that wasn't the point.  And I wasn't seriously suggesting we would get such relativisticly high speeds, just jokingly pointing out what would happen if we did them.  We could always work out how long the perceived journey would last if we were to steadily accelerate to 1c for the first 2ly then decelerate for the last 2ly.  Or perhaps work on the 'safer' option of going for an experienced acceleration (1g? 2g?) and corresponding deceleration for either half of the journey[1]...)



Back to current foreseeable reality, once we get space habitats up and running and not (totally!) reliant upon either direct or 'electrified' solar power whilst being self-providing for most things then what we could do is apply this principle to a 'mobile' space-station to which we cram on  storage-pods full of varying amounts of hard-to-recycle substances and bolt on whatever propulsion systems we have by then (something ionic?) and let it go boldly where no-one has been bold before.  (To paraphrase for the benefit of split-infinitive decriers.)  Yes, I imagine allowing for a generation or two of travel (one way[2]), and that it not even start until we've had a generation or two of local space-colonisation to get our feet 'wet' with the relevant technology and get it up-to-spec, develop anything new that we can, improve that and (most importantly) beat most of the bugs out of it as well...

If we end up sending tin-cans of frozen humans (or embryos?), I'd be quite disappointed, but I'm not ruling that out either if it turns out that's the 'best' solution at the time of launch.  But unless we get some sort of 'Zefram Cochrane' moment out of someone's experimental/theoretical physics dissertation, sometime soon, I very much doubt I'm going to see the start of (let alone take part in!) any sort of journey like this.  But you can probably leave me to my dreams.


[1] Let's see, ignoring the relativistic effects that we seek, with 9.8m/s per second increase over two years that would take us to 61,852,896m/s, wouldn't it?  c= 3x10⁸, so a tad over 0.2c, so we'd reach only 96-ish percent of the time passing (at the top end) of what 'actually' passed for the non-travelling observer...  So doesn't sound like we need to bother too much with integrals to work out how that all works when you add in the changing T/T₀ factor, it'd still take almost four years (apparent) to get there, such a short distance away.  Now, sustaining 3g (possible in the long term? ...probably would need a lot of risky training/acclimatising) would give a "raw max" time dilation that would make 4y seem like 2.5-ish...  still not good enough, especially as most of the time you woukdn't be going that fast in the first place...  but such a book-ended journey to somewhere more than 10ly distant could give us some calculations to do that give far more worthy "trip-shortening" tricks... albeit for a longer trip both in objective and subjective POVs...))

[2] And let those who actually reach the New World work out whether they want to try settling themselves there indefinitely (orbitally or any bit of rock they can find), try to return back here or even send themselves on yet another hop.  Assuming there's nobody there already (one of us, or Someone Else) with some form of hop-drive that makes their little Kon-Tiki trip passé and out-classed.

[vadia]

until we can rework physics it seems to me a multi-generational approach is the only reasonable approach to making it to our neighboring stars' planets.