Manned Space Travel.....Pbbbbbttttttt!

[Iti oj]

Good points.
On a scale of one to a couple of millions my concern about such matters is
way out there lost in the couple of millions.
I love sci-fi.
So many possibilities in the human imagination.

For me this is top 5 maybe even 3.

 

[Brickjectivity]

OK, we've been to the Moon, & it was fun.
But Mars is a completely different animal, with far more daunting problems & costs awaiting.
Some say we need to colonize it to preserve our species.

Venus and Mercury are a better gamble if preserving the species is the goal, because despite hot temperatures there is at least lots of solar energy available. Mars is going to take a lot of warming up.

There are better places to spend money.
Look at this bargain (only a billion & a half dollars).....

Government money, yes; but its possible that private firms or religions may want to establish Martian colonies. They can spend their money how they like.

It's not only cheap, but there's no chance it will crash & burn during its long mission.

RC Racers are even cheaper and easily repaired. What's your point?

Mars is just in our backyard....but this fella lets us see across the universe with a new & powerful vision.
And it has a greater chance of finding alien life.

Finding alien life is perhaps not as glamorous as it used to be.

 

[Quetzal]

Venus and Mercury are a better gamble if preserving the species is the goal, because despite hot temperatures there is at least lots of solar energy available. Mars is going to take a lot of warming up.

I disagree. Venus has a dense atmosphere made up of mostly CO2. Which is great for keeping warmth from going out, but is awful for letting solar energy in. Mercury, on the other hand, is so hot that I believe our biggest challenge would be to get instruments to function properly. This is before we can even begin to toy with the idea of taking a stroll.

 

[Kirran]

I'm just gonna shout Asteroids! Asteroids! Asteroids! a few times.

That done, there are many great advantages to asteroids as the basis for human settlement of the solar system. For starters, you haven't got anywhere near the delta-v barriers to overcome as you do for operating a settlement on Mars or the Moon. Many great Near-Earth Asteroids (NEAs) are much closer than Mars in energetic terms, and have negligible gravity wells.

Since the '70s we've had working models of space habitats and ways by which such ventures could be made profitable overall. In particular, we'd be using asteroidal material for the construction of space-based facilities for use in other space exploration efforts (no need to launch stuff out of Earth's gravity well) and for setting up space-based solar power facilities. Really valuable resources can be shipped down to Earth too. There's also plenty of good science to be done.

We can produce space habitats which simulate 1g of gravity through centripetal force. We have several designs, including bolos, toruses, cylinders etc.

 

[Iti oj]

I'm just gonna shout Asteroids! Asteroids! Asteroids! a few times.

That done, there are many great advantages to asteroids as the basis for human settlement of the solar system. For starters, you haven't got anywhere near the delta-v barriers to overcome as you do for operating a settlement on Mars or the Moon. Many great Near-Earth Asteroids (NEAs) are much closer than Mars in energetic terms, and have negligible gravity wells.

Since the '70s we've had working models of space habitats and ways by which such ventures could be made profitable overall. In particular, we'd be using asteroidal material for the construction of space-based facilities for use in other space exploration efforts (no need to launch stuff out of Earth's gravity well) and for setting up space-based solar power facilities. Really valuable resources can be shipped down to Earth too. There's also plenty of good science to be done.

We can produce space habitats which simulate 1g of gravity through centripetal force. We have several designs, including bolos, toruses, cylinders etc.

I'm down let's do that. Let's do all the space things

 

[beenherebeforeagain]

Good points, but meanwhile we have an ear on an entire galaxy, and we hear nothing but the 'great silence' . Perhaps we can take this at face value?

This is a particularly large, nice, hospitable galaxy, if we are alone here, it doesn't bode well for other galaxies.

We do not have, nor have we ever had, "an ear on the entire galaxy." The project using the Arecibo radio telescope scans a limited portion of the sky in a small strip that eventually has given relatively full coverage area-wise, but not timewise to a band around the celestial equator.

Most of the other projects target a limited number of nearby stars, at a limited range of radio frequencies, and often "listening" to any one star for no more than a few minutes a day.

As it is, the amount of data coming in from the various studies each day outstrips the available analytic capability (despite Seti@home), and most of the data is recorded for future analysis.

And, the reality of radio signals is that almost all radio emissions from our technology to date would not be detectable by an Arecibo-sized detector even a few dozen light-years away.

This argument that we "should" have heard alien broadcasts by now is BS, even if civilizations are common.

 

[Quetzal]

I'm just gonna shout Asteroids! Asteroids! Asteroids! a few times.

That done, there are many great advantages to asteroids as the basis for human settlement of the solar system. For starters, you haven't got anywhere near the delta-v barriers to overcome as you do for operating a settlement on Mars or the Moon. Many great Near-Earth Asteroids (NEAs) are much closer than Mars in energetic terms, and have negligible gravity wells.

Since the '70s we've had working models of space habitats and ways by which such ventures could be made profitable overall. In particular, we'd be using asteroidal material for the construction of space-based facilities for use in other space exploration efforts (no need to launch stuff out of Earth's gravity well) and for setting up space-based solar power facilities. Really valuable resources can be shipped down to Earth too. There's also plenty of good science to be done.

We can produce space habitats which simulate 1g of gravity through centripetal force. We have several designs, including bolos, toruses, cylinders etc.

Nice! I need to look more into this.

 

[Kirran]

I'm down let's do that. Let's do all the space things

We only need to get the majority of a major industrial power's population behind this and we're good to go.

 

[Iti oj]

We only need to get the majority of a major industrial power's population behind this and we're good to go.

We need two. Space race. Part 2

 

[Kirran]

We need two. Space race. Part 2

Ah, you crafty strategist you.

 

[Brickjectivity]

I disagree. Venus has a dense atmosphere made up of mostly CO2. Which is great for keeping warmth from going out, but is awful for letting solar energy in. Mercury, on the other hand, is so hot that I believe our biggest challenge would be to get instruments to function properly. This is before we can even begin to toy with the idea of taking a stroll.

It is a toss up. Mercury has cold spots with ice in some of its craters. Venus surface is inaccessible, but the thick atmosphere might allow life in the sky. At least you can pop up some solar panels to generate some power. Mars is bleached, has terribly low gravity, has a poor magnetic shield and doesn't get much light, and it has sandstorms. Your best bet is to live underground there.

 

[Kirran]

It is a toss up. Mercury has cold spots with ice in some of its craters. Venus surface is inaccessible, but the thick atmosphere might allow life in the sky. At least you can pop up some solar panels to generate some power. Mars is bleached, has terribly low gravity, has a poor magnetic shield and doesn't get much light, and it has sandstorms. Your best best is to live underground there.

There are zones within the Venusian atmosphere where the atmospheric pressure is one Earth atmosphere where we could have habitats bobbing. Although to be perfectly honest I think much of the population will remain in orbit.

Mars has a good set of resources, is the easiest world for terraforming around if we feel like that in the long term, and there's a lot of good options for buried, surface, crater and lava tunnel settlements. It's also a good waystation on the way to the asteroid belt, although only with a space elevator does it have a chance of being profitable as a resource mine. But to be honest seeing it as just a big mine like an asteroid is missing its true value as a habitable world in the distant future.

But yeah, I think in the long term the vast majority of the human population will be living off of planets.

 

[Iti oj]

Ah, you crafty strategist you.

Maybe space race will be attached to the nuke race re. Trump Twitter and Putin.

 

[Brickjectivity]

There are zones within the Venusian atmosphere where the atmospheric pressure is one Earth atmosphere where we could have habitats bobbing. Although to be perfectly honest I think much of the population will remain in orbit.

Mars has a good set of resources, is the easiest world for terraforming around if we feel like that in the long term, and there's a lot of good options for buried, surface, crater and lava tunnel settlements. It's also a good waystation on the way to the asteroid belt, although only with a space elevator does it have a chance of being profitable as a resource mine. But to be honest seeing it as just a big mine like an asteroid is missing its true value as a habitable world in the distant future.

But yeah, I think in the long term the vast majority of the human population will be living off of planets.

Just playing devils advocate. Mars all the way, baby!

 

[Kirran]

Just playing devils advocate. Mars all the way, baby!

OK!

What is there on Mars that justifies it as a colonisation prospect which is sufficiently important to overcome the immense costs incurred by the changes in delta-V required to traffic between it and Earth or near-Earth space?

 

[beenherebeforeagain]

If it turns out to be possible to build habitats in/on asteroids, it will not make much sense to spend the time and energy that would be necessary for colonizing the Moon, Mars, etc. The energetic costs of descending to the surface safely and then climbing back out of those gravity wells just wouldn't be worth it.

Of course, so far, humans have only launched a few hundred small tin cans into orbit, and built a handful of very expensive tin-can stations in orbit, with just eight manned trips as far as the moon...we have a LLLLOOOOOOONNNNGGGGGG way to go before anyone will live most of their lives in orbit...

 

[Kirran]

It's not really either/or. It's more like what's the best way to bootstrap ourselves into the game.

 

[Guy Threepwood]

We do not have, nor have we ever had, "an ear on the entire galaxy." The project using the Arecibo radio telescope scans a limited portion of the sky in a small strip that eventually has given relatively full coverage area-wise, but not timewise to a band around the celestial equator.

Most of the other projects target a limited number of nearby stars, at a limited range of radio frequencies, and often "listening" to any one star for no more than a few minutes a day.

As it is, the amount of data coming in from the various studies each day outstrips the available analytic capability (despite Seti@home), and most of the data is recorded for future analysis.

And, the reality of radio signals is that almost all radio emissions from our technology to date would not be detectable by an Arecibo-sized detector even a few dozen light-years away.

This argument that we "should" have heard alien broadcasts by now is BS, even if civilizations are common.

Obviously we can't tune in live to the entire galaxy in every direction at one time. But if you ever stood out on a brilliant starlit night in a very dark area, most people haven't- it's obvious why you don't have to.
We only have to search within the galactic plane, which by definition is a very limited portion of the sky, and within that, the densest regions obviously offer the best odds. And ET would also look for us in that narrow plane, in a nice quiet suburb, nice main sequence single yellow star system.. then see nice stable orbits, protective gas giants, an inner rocky planet in the habitable zone.. one thing would lead to another

Our planet has presented an ideal piece of vacant real estate, for hundreds of millions of years. If civilizations were at all common, they would have spotted this for sale sign a 'galactic' mile away- not only would we have heard or seen them, they would have been here personally a long time ago (ancient alien theories not withstanding).

The belief that they are out there but hidden, relies on the further belief that not one single civilization ever developed the capacity to colonize, even though it could have been done with tech. little better than our own, many times over by now-
or that some galactic treaty prevents disturbing uncontacted tribes - not impossible but it's walking a pretty thin line.

But the observation merely supports the math, the odds of another planet like Earth existing in the universe, far less our own galaxy, are not too great.

 

[Kirran]

Obviously we can't tune in live to the entire galaxy in every direction at one time. But if you ever stood out on a brilliant starlit night in a very dark area, most people haven't- it's obvious why you don't have to.
We only have to search within the galactic plane, which by definition is a very limited portion of the sky, and within that, the densest regions obviously offer the best odds. And ET would also look for us in that narrow plane, in a nice quiet suburb, nice main sequence single yellow star system.. then see nice stable orbits, protective gas giants, an inner rocky planet in the habitable zone.. one thing would lead to another

Our planet has presented an ideal piece of vacant real estate, for hundreds of millions of years. If civilizations were at all common, they would have spotted this for sale sign a 'galactic' mile away- not only would we have heard or seen them, they would have been here personally a long time ago (ancient alien theories not withstanding).

The belief that they are out there but hidden, relies on the further belief that not one single civilization ever developed the capacity to colonize, even though it could have been done with tech. little better than our own, many times over by now-
or that some galactic treaty prevents disturbing uncontacted tribes - not impossible but it's walking a pretty thin line.

But the observation merely supports the math, the odds of another planet like Earth existing in the universe, far less our own galaxy, are not too great.

An established space-faring civilisation would find it far more appealing to modify its surrounding environment to its needs than to go jetting off thousands upon thousands of light years for some life-bearing planet. It's a common trope in science fiction, I know, but that doesn't mean it's realistic.

 

[Guy Threepwood]

An established space-faring civilisation would find it far more appealing to modify its surrounding environment to its needs than to go jetting off thousands upon thousands of light years for some life-bearing planet. It's a common trope in science fiction, I know, but that doesn't mean it's realistic.

At first yes... so did microbes on Earth, and their feat of eventually colonizing Earth from a single ancestor- ,( if you subscribe to that sort of thing)- represented a similar scale and algorithm. The more they spread, one niche at a time, the less prone to extinction, complete colonization would be inevitable eventually- and the time scales available are vast, many times what would be required.

But apparently this never happened.