why outer space?

From: Al Globus [mailto:aglobus@...]

> While I disagree with much of what Zubrin says, I have to agree with
> him that growing crops for any significant number of people using
> artificial illumination is probably going to require impractical
> amounts of energy.

Zubrin is a great speaker and a good engineer, but he doesn't know much
about plants. NASA Ames has an enclosed grow unit about the size of a
largish bedroom with a high ceiling that can more-or-less feed one
person forever (particularly if you like lettuce).

I hasten to add that he was speaking in reference to large human colonies of
several thousand, and not of small stations or bases of less than a hundred.
For example, he was calculating the energy costs to illuminate a land area
the size of Costa Rica with the same amount of light as Costa Rica gets from
the sun.

Yes, it does use a
lot of energy, but there are plans to test it in Antartica and,
remember, orbit has a lot of energy.

But don't forget that Zubrin dismisses the idea of living in orbit, so he
doesn't expect us to ever capitalize on the abundant availability of energy
in free space. In fact, he specifically argues that you can't grow crops in
space, or anyplace else besides Earth and Mars, it would seem.

It turns out that plants grow like
gangbusters if you give them just the right stuff -- usually a lot of
light for long hours. The Ames unit grows plants so fast that most
pathogens are left behind -- their life cycle is too slow to keep up
with the plants.

That sounds like a good deal, since it may occasionally happen that a
pathogen manages to sneak into our space gardens despite our best efforts.
But even when that happens, agriculture in space will be far more
compartmentalized than is the case here on Earth, so containing unwelcome
lifeforms should be much easier.

Regards,

Mike Combs

From:
Al Globus [mailto:aglobus@...]
> While I disagree with much of what Zubrin says, I have to agree with
> him that growing crops for any significant number of people using
> artificial illumination is probably going to require impractical
> amounts of energy.
Zubrin is a great speaker and a good engineer, but he doesn't know much
about plants. NASA Ames has an enclosed grow unit about the size of a
largish bedroom with a high ceiling that can more-or-less feed one
person forever (particularly if you like lettuce).

I hasten to add that he was speaking in reference to large human colonies of several thousand, and not of small stations or bases of less than a hundred. For example, he was calculating the energy costs to illuminate a land area the size of Costa Rica with the same amount of light as Costa Rica gets from the sun.

Yes, it does use a
lot of energy, but there are plans to test it in Antartica and,
remember, orbit has a lot of energy.

But don't forget that Zubrin dismisses the idea of living in orbit, so he doesn't expect us to ever capitalize on the abundant availability of energy in free space. In fact, he specifically argues that you can't grow crops in space, or anyplace else besides Earth and Mars, it would seem.

It turns out that plants grow like
gangbusters if you give them just the right stuff -- usually a lot of
light for long hours. The Ames unit grows plants so fast that most
pathogens are left behind -- their life cycle is too slow to keep up
with the plants.

That sounds like a good deal, since it may occasionally happen that a pathogen manages to sneak into our space gardens despite our best efforts. But even when that happens, agriculture in space will be far more compartmentalized than is the case here on Earth, so containing unwelcome lifeforms should be much easier.

Regards,
Mike Combs