Heat management, recycling, $, and space ores

From: "Darren Brown"
To:
Sent: Tuesday, November 28, 2000 6:26 PM
Subject: [spacesettlers] Re: Heat management, recycling, $, and space ores

> --- In spacesettlers@egroups.com, ian.woollard@t... wrote:
>
> Greetings Ian,
>
> > > > 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.
> >
> > True.
> >
> > > 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.
> >
> > This is mostly/partly true. Consider: Apollo 13
> >
> > In Apollo 13 when the problems happened the temperature actually
> > dropped to around freezing. They have to heat the capsule to
> > keep it warm.
>
> True, but didn't they have leaking from fuel tanks and from a ruptured
> LOX tank? If they were leaking then a lot of heat could be taken away
> by evaporation (I mean as it flows out it touches the uninsulated
> surfaces, not that the heat flowed through the heavy insulation around
> the LOX tank) and then the craft was only holding three main heat
> sources, the humans in it. Now people do generate a lot of heat per
> cubic centimetre but there is a lot of space to heat and maybe heat
> being drawn off by leaking containers.
>
> > Apart from the sun- space is actually very cold indeed.
>
> I agree but it is still hard to radiate heat faster than you make it.
>
> > On the earth the temperature should be below zero but the
> > natural greenhouse effect raises the temperature way
> > up.
> >
> > Of course in a classical O'Neil habitat the problem is
> > reversed, you have something approaching a heat trap,
> > and heat dispersal is a real nuisance.
> >
> > Still, by engineering the 'albedo' of your space
> > settlement I believe you can engineer the
> > default temperature of your settlement. The rest
> > you can make up by active elements of whatever kind
> > you choose...
>
> Maybe but it just might be cheaper to add a few fins to get rid of
> what you don't want.
>
Tom,
The ISS has several expandable heat radiators for just such heat management.

Tom