The Case For Space Colonization

[DBT]

There is no such thing as perfect safety. There is acceptable risk and risk management. There is the potential for casualties in any endeavor that involves risk.

 

[Loren Pechtel]

You have no idea what my point was. This is totally non-responsive.

I am comparing two situations.

A space ship where survival is totally dependent on human technology and the planet Earth where humans can survive without any human technology.

In the former situation humans will not last long.

In the latter they can last a lot longer. And even with extremely faulty technology can survive a lot better.

You cannot survive faulty technology if your survival is entirely dependent on it.

A plane can land and be looked at and be repaired.

A spaceship cannot land anywhere to be repaired. The life support systems can never go down.

The plane can't land on the ocean. When you're flying across the water if the plane breaks the video I linked shows the probable result. Furthermore, you're in an environment where you can't even breathe. Your survival is totally dependent on the plane. We don't consider that a problem for crossing an ocean, why is it somehow magically a showstopper in space?

It just means you have backups. In many cases you have backup on the backups.

Are you saying planes don't ever go down?

When the technology fails people die.

Just like being in space.

The point is that being in a position where your life is dependent upon technology doesn't act a showstopper here on Earth, why should it be a showstopper off Earth?

 

[4321lynx]

Are you saying planes don't ever go down?

When the technology fails people die.

Just like being in space.

The point is that being in a position where your life is dependent upon technology doesn't act a showstopper here on Earth, why should it be a showstopper off Earth?

The point is that living on Mars is like flying over the ocean permanently, and just hoping that the refuelling crew are working, know their job and can find you. nd there are other problems:

See posts 1 to 8 here

https://www.physicsforums.com/threads/survival-on-mars.765443/

Eachneeds its own solution and backups to that solution.. Robots will be easier to maintain and repkace as necessary.

 

[untermensche]

Are you saying planes don't ever go down?

When the technology fails people die.

Just like being in space.

The point is that being in a position where your life is dependent upon technology doesn't act a showstopper here on Earth, why should it be a showstopper off Earth?

Your life is not dependent on technology never breaking down.

Technology can break down here on Earth, and does all the time, because we are not dependent on it working every second of every day. We can survive a long time without any technology. We can live for days without any technology. If we have food and water on hand we can live a long time without any technology. People stuck in the middle of Katrina survived for days without any technology.

But in some man made machine in space vital systems can never break down even for a few minutes.

 

[Terrell]

I'd love to see us explore & colonize space, but I have my doubts that there will be self-sustaining colonies off world in my lifetime. I hope I'm wrong.

On the issue of lower gravity; do we know what the minimum gravity our organs require to not have problems? If there's enough gravity on Mars to avoid organ damage, why not just weave weights into our clothing to protect our bone & muscle density? Perhaps your shirt & pants could be weighted with something comparable to chain mail, with the weight distributed evenly across your clothing.

I would think that any permanent colony that's intended to be self-sustaining will need women to have children there. I don't know if that's practical or even doable. Might cause birth defects, but I don't think we'll really know until humans actually try to produce children on Mars.

 

[Loren Pechtel]

Are you saying planes don't ever go down?

When the technology fails people die.

Just like being in space.

The point is that being in a position where your life is dependent upon technology doesn't act a showstopper here on Earth, why should it be a showstopper off Earth?

Your life is not dependent on technology never breaking down.

Technology can break down here on Earth, and does all the time, because we are not dependent on it working every second of every day. We can survive a long time without any technology. We can live for days without any technology. If we have food and water on hand we can live a long time without any technology. People stuck in the middle of Katrina survived for days without any technology.

But in some man made machine in space vital systems can never break down even for a few minutes.

You utterly missed the point about backup systems.

Consider the ISS: The primary source of oxygen is electrolysis of water. Something goes wrong and they have tanks of oxygen as a backup. They also have oxygen candles.

The airplane can get to safety faster, it only has compressors/air conditioners (if the air conditioner fails you can't use the compressors without cooking the passengers) and oxygen candles as a backup.

 

[untermensche]

Your life is not dependent on technology never breaking down.

Technology can break down here on Earth, and does all the time, because we are not dependent on it working every second of every day. We can survive a long time without any technology. We can live for days without any technology. If we have food and water on hand we can live a long time without any technology. People stuck in the middle of Katrina survived for days without any technology.

But in some man made machine in space vital systems can never break down even for a few minutes.

You utterly missed the point about backup systems.

Consider the ISS: The primary source of oxygen is electrolysis of water. Something goes wrong and they have tanks of oxygen as a backup. They also have oxygen candles.

The airplane can get to safety faster, it only has compressors/air conditioners (if the air conditioner fails you can't use the compressors without cooking the passengers) and oxygen candles as a backup.

Backup systems can fail too.

How many backup life support systems do you think are possible to engineer into one ship? A backup system is only a short term solution.

The second they all go down at once people start dying.

How long can they be maintained to never break down?

A year? A decade? A century?

Maybe they could last a year or two. The space satellites only survive because when something breaks down it can be replaced from Earth. Travel to Mars may be possible but exploration beyond the Solar System at this point is a pipe dream except with unmanned vehicles.

 

[Jokodo]

Your life is not dependent on technology never breaking down.

Technology can break down here on Earth, and does all the time, because we are not dependent on it working every second of every day. We can survive a long time without any technology. We can live for days without any technology. If we have food and water on hand we can live a long time without any technology. People stuck in the middle of Katrina survived for days without any technology.

But in some man made machine in space vital systems can never break down even for a few minutes.

You utterly missed the point about backup systems.

Consider the ISS: The primary source of oxygen is electrolysis of water. Something goes wrong and they have tanks of oxygen as a backup. They also have oxygen candles.

The airplane can get to safety faster, it only has compressors/air conditioners (if the air conditioner fails you can't use the compressors without cooking the passengers) and oxygen candles as a backup.

Backup systems can fail too.

How many backup life support systems do you think are possible to engineer into one ship? A backup system is only a short term solution.

The second they all go down at once people start dying.<snip>

Of course backup systems can fail. More likely than not, they even have a higher failure rate than the main system because we expect not to be relying on them much. But the more redundant a system, the more improbable it is for all components to fail at the same time. Simple statistics tells us that with sufficient redundancy, it will be a cold day in hell before "the second they all go down at once" comes, even if each individual is very much fallible.

Assume that when the main system breaks down, it takes a month to repair it - if someone's still around to repair it. Assume a failure rate of 1/100 per month for the main system and anything between 1/10 and 1/50 for the backups (as per the above, we're making the backups cheap because we don't plan to rely on them for extended periods of time).

Without backups, the chance of a fatal breakdown is 1/100 per month. After that, no-one's left to repair the system. This means an average life expectancy of the mission of 8 years four months.

With a single semi-reliable backup (monthly failure rate of 1/50), the chance of the second system breaking down before the crew manages to repair the first is 1/(100*50) per month. The average life expectancy of the mission thus rises to 417 years - even though the backup's security is actually inferior to the main system's.

With three independent ultra-cheap and unreliable backups with a failure rate of 1/10 per month, chance of fatal failure of all systems is 1/(100 * 10³) and the life extectancy rises to 8334 years. With three independent semi-reliable backups (1/50 monthly breakdown rate as in the last example with a single backup), we're at a 1/(100 * 50³) per month breakdown rate and a life expectancy of over a million years!

 

[bilby]

Mir was continuously occupied for 3,644 days without a single fatality or serious problem with life support. Valeri Polyakov spent 437 consecutive days onboard in 1994/5; he is still alive and working as the Deputy Director of the Ministry of Public Health in Moscow at the age of 75. He is in better health than most 75 year old men.

The ISS has been continuously occupied for 17 years, 3 months and 13 days at the time of this post, and there is no current plan or expectation that this will end any time soon; Roscosmos and NASA have committed to operate the station at least until 2024.

If you can safely operate a crewed space station for a quarter of a century, it doesn't seem implausible that you could do so indefinitely. Particularly as each new station design builds on the lessons from the previous one, and can take advantage of advances in materials and technologies.

A modern car is expected to be both better designed and more reliable than one built eighteen years ago.

 

[Loren Pechtel]

Your life is not dependent on technology never breaking down.

Technology can break down here on Earth, and does all the time, because we are not dependent on it working every second of every day. We can survive a long time without any technology. We can live for days without any technology. If we have food and water on hand we can live a long time without any technology. People stuck in the middle of Katrina survived for days without any technology.

But in some man made machine in space vital systems can never break down even for a few minutes.

You utterly missed the point about backup systems.

Consider the ISS: The primary source of oxygen is electrolysis of water. Something goes wrong and they have tanks of oxygen as a backup. They also have oxygen candles.

The airplane can get to safety faster, it only has compressors/air conditioners (if the air conditioner fails you can't use the compressors without cooking the passengers) and oxygen candles as a backup.

Backup systems can fail too.

How many backup life support systems do you think are possible to engineer into one ship? A backup system is only a short term solution.

The second they all go down at once people start dying.

How long can they be maintained to never break down?

A year? A decade? A century?

Maybe they could last a year or two. The space satellites only survive because when something breaks down it can be replaced from Earth. Travel to Mars may be possible but exploration beyond the Solar System at this point is a pipe dream except with unmanned vehicles.

It doesn't require that they never break down. It only requires they don't all break down at the same time. There have been multiple breakdowns in the oxygen system of the ISS. Nobody has died.

 

[Loren Pechtel]

With a single semi-reliable backup (monthly failure rate of 1/50), the chance of the second system breaking down before the crew manages to repair the first is 1/(100*50) per month. The average life expectancy of the mission thus rises to 417 years - even though the backup's security is actually inferior to the main system's.

With three independent ultra-cheap and unreliable backups with a failure rate of 1/10 per month, chance of fatal failure of all systems is 1/(100 * 10³) and the life extectancy rises to 8334 years. With three independent semi-reliable backups (1/50 monthly breakdown rate as in the last example with a single backup), we're at a 1/(100 * 50³) per month breakdown rate and a life expectancy of over a million years!

And note that in many cases the backup systems are ultra reliable.

For example, oxygen candles. The only moving part is the igniter. They're a backup system because of the weight.

 

[Loren Pechtel]

Mir was continuously occupied for 3,644 days without a single fatality or serious problem with life support. Valeri Polyakov spent 437 consecutive days onboard in 1994/5; he is still alive and working as the Deputy Director of the Ministry of Public Health in Moscow at the age of 75. He is in better health than most 75 year old men.

I disagree--there were serious incidents on Mir that Moscow covered up.

The ISS has been continuously occupied for 17 years, 3 months and 13 days at the time of this post, and there is no current plan or expectation that this will end any time soon; Roscosmos and NASA have committed to operate the station at least until 2024.

If you can safely operate a crewed space station for a quarter of a century, it doesn't seem implausible that you could do so indefinitely. Particularly as each new station design builds on the lessons from the previous one, and can take advantage of advances in materials and technologies.

A modern car is expected to be both better designed and more reliable than one built eighteen years ago.

Second this.

 

[bilby]

Mir was continuously occupied for 3,644 days without a single fatality or serious problem with life support. Valeri Polyakov spent 437 consecutive days onboard in 1994/5; he is still alive and working as the Deputy Director of the Ministry of Public Health in Moscow at the age of 75. He is in better health than most 75 year old men.

I disagree--there were serious incidents on Mir that Moscow covered up.

Even if it were true, how could you possibly know this?

The ISS has been continuously occupied for 17 years, 3 months and 13 days at the time of this post, and there is no current plan or expectation that this will end any time soon; Roscosmos and NASA have committed to operate the station at least until 2024.

If you can safely operate a crewed space station for a quarter of a century, it doesn't seem implausible that you could do so indefinitely. Particularly as each new station design builds on the lessons from the previous one, and can take advantage of advances in materials and technologies.

A modern car is expected to be both better designed and more reliable than one built eighteen years ago.

Second this.

 

[Jokodo]

With a single semi-reliable backup (monthly failure rate of 1/50), the chance of the second system breaking down before the crew manages to repair the first is 1/(100*50) per month. The average life expectancy of the mission thus rises to 417 years - even though the backup's security is actually inferior to the main system's.

With three independent ultra-cheap and unreliable backups with a failure rate of 1/10 per month, chance of fatal failure of all systems is 1/(100 * 10³) and the life extectancy rises to 8334 years. With three independent semi-reliable backups (1/50 monthly breakdown rate as in the last example with a single backup), we're at a 1/(100 * 50³) per month breakdown rate and a life expectancy of over a million years!

And note that in many cases the backup systems are ultra reliable.

For example, oxygen candles. The only moving part is the igniter. They're a backup system because of the weight.

They don't have to be though. Any backup with a non-zero chance of running successfully for as long as it takes to bring the main system back online constitutes an improvement of safety.

 

[Jokodo]

Mir was continuously occupied for 3,644 days without a single fatality or serious problem with life support. Valeri Polyakov spent 437 consecutive days onboard in 1994/5; he is still alive and working as the Deputy Director of the Ministry of Public Health in Moscow at the age of 75. He is in better health than most 75 year old men.

The ISS has been continuously occupied for 17 years, 3 months and 13 days at the time of this post, and there is no current plan or expectation that this will end any time soon; Roscosmos and NASA have committed to operate the station at least until 2024.

If you can safely operate a crewed space station for a quarter of a century, it doesn't seem implausible that you could do so indefinitely. Particularly as each new station design builds on the lessons from the previous one, and can take advantage of advances in materials and technologies.

A modern car is expected to be both better designed and more reliable than one built eighteen years ago.

But neither Mir nor the ISS are/were fully autonomous.

The requirement on their backup systems was solely to keep the crew alive for as long as it takes to schedule and implement an emergency supply from earth. The requirement on a backup system on a fully autonomous station would be to keep the crew alive for as long as it may take them to repair the main system with the materials and tools available on the station, which may be considerably longer.

 

[fromderinside]

Even if it were true, how could you possibly know this?

Army technician working at a base on the north island of Japan?

 

[bilby]

Mir was continuously occupied for 3,644 days without a single fatality or serious problem with life support. Valeri Polyakov spent 437 consecutive days onboard in 1994/5; he is still alive and working as the Deputy Director of the Ministry of Public Health in Moscow at the age of 75. He is in better health than most 75 year old men.

The ISS has been continuously occupied for 17 years, 3 months and 13 days at the time of this post, and there is no current plan or expectation that this will end any time soon; Roscosmos and NASA have committed to operate the station at least until 2024.

If you can safely operate a crewed space station for a quarter of a century, it doesn't seem implausible that you could do so indefinitely. Particularly as each new station design builds on the lessons from the previous one, and can take advantage of advances in materials and technologies.

A modern car is expected to be both better designed and more reliable than one built eighteen years ago.

But neither Mir nor the ISS are/were fully autonomous.

The requirement on their backup systems was solely to keep the crew alive for as long as it takes to schedule and implement an emergency supply from earth. The requirement on a backup system on a fully autonomous station would be to keep the crew alive for as long as it may take them to repair the main system with the materials and tools available on the station, which may be considerably longer.

Sure. But we are talking about stuff no further away than Mars. Not a situation where there can never be another resupply or repair mission.

 

[untermensche]

Backup systems can fail too.

How many backup life support systems do you think are possible to engineer into one ship? A backup system is only a short term solution.

The second they all go down at once people start dying.<snip>

Of course backup systems can fail. More likely than not, they even have a higher failure rate than the main system because we expect not to be relying on them much. But the more redundant a system, the more improbable it is for all components to fail at the same time. Simple statistics tells us that with sufficient redundancy, it will be a cold day in hell before "the second they all go down at once" comes, even if each individual is very much fallible.

Assume that when the main system breaks down, it takes a month to repair it - if someone's still around to repair it. Assume a failure rate of 1/100 per month for the main system and anything between 1/10 and 1/50 for the backups (as per the above, we're making the backups cheap because we don't plan to rely on them for extended periods of time).

Without backups, the chance of a fatal breakdown is 1/100 per month. After that, no-one's left to repair the system. This means an average life expectancy of the mission of 8 years four months.

With a single semi-reliable backup (monthly failure rate of 1/50), the chance of the second system breaking down before the crew manages to repair the first is 1/(100*50) per month. The average life expectancy of the mission thus rises to 417 years - even though the backup's security is actually inferior to the main system's.

With three independent ultra-cheap and unreliable backups with a failure rate of 1/10 per month, chance of fatal failure of all systems is 1/(100 * 10³) and the life extectancy rises to 8334 years. With three independent semi-reliable backups (1/50 monthly breakdown rate as in the last example with a single backup), we're at a 1/(100 * 50³) per month breakdown rate and a life expectancy of over a million years!

You're assuming every breakdown can be fixed.

What I'm assuming is just like on Earth some breakdowns require new parts.

So either you make the new part like Apollo 13 out of stuff lying around or as with the space satellites have the new part flown up and delivered.

Unless you can manufacture every vital part of the life support systems you will eventually have a fatal breakage.

How long could human systems last in space? Who knows? But not likely long enough to reach another Solar System. That's a pipe dream with our current technology.

 

[Jokodo]

Backup systems can fail too.

How many backup life support systems do you think are possible to engineer into one ship? A backup system is only a short term solution.

The second they all go down at once people start dying.<snip>

Of course backup systems can fail. More likely than not, they even have a higher failure rate than the main system because we expect not to be relying on them much. But the more redundant a system, the more improbable it is for all components to fail at the same time. Simple statistics tells us that with sufficient redundancy, it will be a cold day in hell before "the second they all go down at once" comes, even if each individual is very much fallible.

Assume that when the main system breaks down, it takes a month to repair it - if someone's still around to repair it. Assume a failure rate of 1/100 per month for the main system and anything between 1/10 and 1/50 for the backups (as per the above, we're making the backups cheap because we don't plan to rely on them for extended periods of time).

Without backups, the chance of a fatal breakdown is 1/100 per month. After that, no-one's left to repair the system. This means an average life expectancy of the mission of 8 years four months.

With a single semi-reliable backup (monthly failure rate of 1/50), the chance of the second system breaking down before the crew manages to repair the first is 1/(100*50) per month. The average life expectancy of the mission thus rises to 417 years - even though the backup's security is actually inferior to the main system's.

With three independent ultra-cheap and unreliable backups with a failure rate of 1/10 per month, chance of fatal failure of all systems is 1/(100 * 10³) and the life extectancy rises to 8334 years. With three independent semi-reliable backups (1/50 monthly breakdown rate as in the last example with a single backup), we're at a 1/(100 * 50³) per month breakdown rate and a life expectancy of over a million years!

You're assuming every breakdown can be fixed.

What I'm assuming is just like on Earth some breakdowns require new parts.

So either you make the new part like Apollo 13 out of stuff lying around or as with the space satellites have the new part flown up and delivered.

Unless you can manufacture every vital part of the life support systems you will eventually have a fatal breakage.

I'm sure you're the first person to have thought of this. Not.
It seems rather obvious that, for any such mission, the ability to manufacture every vital part with the resources available on the station should be a high priority design constraint.

How long could human systems last in space? Who knows? But not likely long enough to reach another Solar System. That's a pipe dream with our current technology.

It may well be a pipe dream, but for a different set of reasons: For sociological and psychological reasons rather than technological ones. We have no idea how a small and isolated group of people, starting out at a high technological level, will develop over hundreds or thousands of generations. It's entirely possible to engineer sufficient redundancy into a system while making it easy to repair every vital component to guarantee survival for hundreds of thousands of years with the founder crew's skill set available. Not easy or trivial, but possible. But we have no idea how to make sure the society on board will not loose that skill set, or even become illiterate, within a mere hundreds of years. The closest we have to a natural sociological experiment that'd shed light on the issue is the experience of the Easter Island, and that one isn't too promising.

Also, the OP and thread title talk about space, not necessarily interstellar space.

 

[James Brown]

Supposedly the Oort cloud extends approximately 2 light years out from the sun. Assuming that Proxima Centauri has a similar-sized Oort cloud, then humans can "island hop" from one object to another, from one star to the next, each hop taking place within a relatively short time span.

This is obviously no Battlestar Galactica-style of space travel, but it's much safer.