Heat management, recycling, $, and space ores

From: Dr. Omni [mailto:dromni@...]

Hi, Mike! I'm honored to see you participating of our list! Your site on
space settlements was one of the things that helped me to recover from my
Mars terraforming brainwash... ;-) Well, now lets go to your message...

What a nice thing to say. Thanks.

Are there cases were we would not need to dump excess heat? Hmmmm...

Not hardly. Every use of energy results in waste heat, which must be shed.

Nuke-powered habitats would have to drain excess heat from the reactor, but
perhaps not from the habitat itself; and "tether-powered" habitats (I don't
know if there is a more elegant name for this, a habitat that would generate
electricity directly by using a tether to cross the force lines of a
planetary magnetic field) maybe would not need any dumping at all, if
cleverly designed. Is that the case?

Even in habitats without sunlit vales, and even in habitats which use very
efficient methods for generation of power, waste heat will still be
generated. It's somewhat harder to get rid of waste heat in a vacuum.

As an aside, please know that a tether-powered habitat would pay for it's
electrical power with a constantly lowering orbit.

What are CELSS?

Closed Ecology Life Support System.

I think that they're forgetting a small detail: usually money *is*
everything for people who would have enough money to finance immediate Mars
exploration. ;-)

Exactly. Not long ago on a space newsgroup I told one of them, "No bucks,
no Buck Rogers". The reality which they don't want to face is that the
total number of people truly committed to settling space could not pool
enough money to do the job. That means, barring the government doing it for
us, that the biggest majority of people funding development of space will be
doing so with no particular interest in space settlement. That means we
must have a profitable business plan.

I agree with the idea of SPS. Actually, I tend to see it as a solution for
the energy problem on Earth more likely than fusion reactors. Fifty years
ago, many researches predicted that in fifty years we would have viable
fusion at work. Nowadays, they say the same thing... I think that probably
the cost of launching payloads to LEO will drop enough to allow SPS before
we have fusion reactors.

In one article, someone mentioned being at an energy conference and seeing
Glaser present a paper. Afterward, a physicist went up to Glaser and teased
him for presenting such an unrealistic, pie-in-the-sky energy proposal.
"This from a member of the plasma physics community which has been promising
us an eminent breakthrough in commercial fusion for the past 45 years."

I've heard it suggested that animosity toward SPS from this same community
of physicists (perhaps concerned about possible competition) might account
for the rough treatment SPS received in the NRC study. I know I sent a
letter to O'Neill asking him if some of the numbers in the NRC study weren't
quite simply wrong. He agreed, referring to the study as "nature faking".

I think that space-mined ores can be brought down to Earth on a relatively
inexpensive way. You have simply to encapsulate them in some heat-resistant
envelope and drop them into the atmosphere, in a way that they'll fall on
some previously assigned crash site. I say "crash site" because, since the
capsule would contain just minerals with minimum processing, it could simply
crash at hundreds of kilometers per hour - after that, bulldozers and trucks
could "re-mine" the debris on the surface.

I would agree that bringing stuff down to Earth takes somewhat less energy
than sending things up, given that one can use the atmosphere for braking.
But it still takes lots of energy. I can almost see a case for the platinum
group metals. And even here, you'd have to be careful about flooding the
market. But for anything else, I think it would be hard to make a profit.

I say, use space ores in space.

I remember a proposal to form space metals into a giant lifting body. Ocean
landing was recommended, as the lifting body would actually float, and could
be towed. That's because it was foam steel: something which was suggested
as an space export before honeycomb composites made it seem less attractive.

That could be advantageous for
nations poor in mineral resources, once space travel is made common. Of
course I'm no space nor mining specialist and my idea of "mining
meteor-delivery" may be very nave in some point.

I'd say the chief problem would be explaining to folks who've seen "Deep
Impact" and "Armageddon" what you were going to do and why they shouldn't
worry about it.

Rgds,

Mike Combs

From:
Dr. Omni [mailto:dromni@...]
Hi, Mike! I'm honored to see you participating of our list! Your site on
space settlements was one of the things that helped me to recover from my
Mars terraforming brainwash... ;-) Well, now lets go to your message...

What a nice thing to say. Thanks.

Are there cases were we would not need to dump excess heat? Hmmmm...

Not hardly. Every use of energy results in waste heat, which must be shed.

Nuke-powered habitats would have to drain excess heat from the reactor, but
perhaps not from the habitat itself; and "tether-powered" habitats (I don't
know if there is a more elegant name for this, a habitat that would generate
electricity directly by using a tether to cross the force lines of a
planetary magnetic field) maybe would not need any dumping at all, if
cleverly designed. Is that the case?

Even in habitats without sunlit vales, and even in habitats which use very efficient methods for generation of power, waste heat will still be generated. It's somewhat harder to get rid of waste heat in a vacuum.

As an aside, please know that a tether-powered habitat would pay for it's electrical power with a constantly lowering orbit.

What are CELSS?

Closed Ecology Life Support System.

I think that they're forgetting a small detail: usually money *is*
everything for people who would have enough money to finance immediate Mars
exploration. ;-)

Exactly. Not long ago on a space newsgroup I told one of them, "No bucks, no Buck Rogers". The reality which they don't want to face is that the total number of people truly committed to settling space could not pool enough money to do the job. That means, barring the government doing it for us, that the biggest majority of people funding development of space will be doing so with no particular interest in space settlement. That means we must have a profitable business plan.

I agree with the idea of SPS. Actually, I tend to see it as a solution for
the energy problem on Earth more likely than fusion reactors. Fifty years
ago, many researches predicted that in fifty years we would have viable
fusion at work. Nowadays, they say the same thing... I think that probably
the cost of launching payloads to LEO will drop enough to allow SPS before
we have fusion reactors.

In one article, someone mentioned being at an energy conference and seeing Glaser present a paper. Afterward, a physicist went up to Glaser and teased him for presenting such an unrealistic, pie-in-the-sky energy proposal. "This from a member of the plasma physics community which has been promising us an eminent breakthrough in commercial fusion for the past 45 years."

I've heard it suggested that animosity toward SPS from this same community of physicists (perhaps concerned about possible competition) might account for the rough treatment SPS received in the NRC study. I know I sent a letter to O'Neill asking him if some of the numbers in the NRC study weren't quite simply wrong. He agreed, referring to the study as "nature faking".

I think that space-mined ores can be brought down to Earth on a relatively
inexpensive way. You have simply to encapsulate them in some heat-resistant
envelope and drop them into the atmosphere, in a way that they'll fall on
some previously assigned crash site. I say "crash site" because, since the
capsule would contain just minerals with minimum processing, it could simply
crash at hundreds of kilometers per hour - after that, bulldozers and trucks
could "re-mine" the debris on the surface.

I would agree that bringing stuff down to Earth takes somewhat less energy than sending things up, given that one can use the atmosphere for braking. But it still takes lots of energy. I can almost see a case for the platinum group metals. And even here, you'd have to be careful about flooding the market. But for anything else, I think it would be hard to make a profit.

I say, use space ores in space.

I remember a proposal to form space metals into a giant lifting body. Ocean landing was recommended, as the lifting body would actually float, and could be towed. That's because it was foam steel: something which was suggested as an space export before honeycomb composites made it seem less attractive.

That could be advantageous for
nations poor in mineral resources, once space travel is made common. Of
course I'm no space nor mining specialist and my idea of "mining
meteor-delivery" may be very nave in some point.

I'd

say the chief problem would be explaining to folks who've seen "Deep Impact" and "Armageddon" what you were going to do and why they shouldn't worry about it.
Rgds,
Mike Combs