reflecting sunlight onto the Moon?

Herm wrote in message . ..
is there no advantage to using a nice nuclear reactor to provide power?..
perhaps use solar heat for processing ores etc.. then take a break during
the dark period.

I would want redundant reactors for life support..


I would suggest the following means to store energy for a lunar base
during the 14 day lunar night: aluminum-oxygen fuel cells. Any base
that is not purely scientific will be trying to produce commercially
desirable products. Oxygen and aluminum, probably derived from
ilmenite readily available on the moon, are items useful for
space-based structures and propellant. So the base generates excess
amounts during the day and consumes them at night. Unlike nuclear
reactors or solar arrays, these fuel cells could also power moon
buggies. Also, rather than making colonists dependent on the
reliabilty of one fixed nuclear reactor (which requires periodic
importation of fuel), fuel cells would be small, numerous, and
possibly able to be made from local materials. See
www.aluminum-power.com.

Bill Bogen wrote:

Oxygen and aluminum, probably derived from
ilmenite readily available on the moon, are items useful for
space-based structures and propellant.

Deriving aluminum from ilmenite would be a neat trick.

Paul

(Geoffrey A. Landis) wrote

This takes
enormous radiators if you use current technology. (Extrapolating
future technology, of course, means the result is anything you want it
to be).

Are the liquid drop (or solid bead) curtains proposed back in
SDI days still in the running for radiators?

triple redundant nuclear power, with one reactor sufficient for life
support, and two sufficient for industrial operation.. with a 30 year fuel
load in it. That should do it..

On 18 May 2004 04:48:18 -0700, (Bill Bogen) wrote:

Also, rather than making colonists dependent on the
reliabilty of one fixed nuclear reactor (which requires periodic
importation of fuel),

Herm
Astropics http://home.att.net/~hermperez

"Ool" wrote in message

The problem most plants have with unnaturally thin air is that they go
into drought mode, evaporating water through their leaves and dehy-
drating. It doesn't matter how much you crank up the air humidity;
the plants still think they're in an environment that's too dry and
lose too much water through their leaves.

Selective breeding and genetic engineering might be able to remedy
that, but until then it's a problem...

(Can't seem to be able to find the link to where I read that...)

OK, so raise the partial pressure of H2O in the atmosphere until the
plants reach equilibrium. What is that pressure? I can imagine a
greenhouse atmosphere that is different in both pressure and
constituent mix from the habitation volume. Molecular seives have been
getting better lately.

Dan

Matthew Montchalin wrote in message ...

| Second, how much light is a minimum for them to survive local 2-week
| night?

I had a Ki plant (also known to some as the Ti plant) that regularly
survived 2 weeks of pitch black night, you just had to keep them warm
during the night, they'll kick into overdrive once you give them light
again. This kind of plant is perfect for hydroponics because it is one
of those things that likes to suck water in through its roots, and pump
it upward through its stem. Unfortunately, it is a non-fruiting plant,
and it is only good to propagate through shoots and cuttings.

As long as I can eat it and get some nourishment, it doesn't have to
be fruit. Of course, it would still be useful for recycling CO2 even
if it's not edible. But if it doesn't make food, it may not
economically compete with chemical CO2 recycling processes.

Just be
sure you give the plant a week of constant light before turning off the
lights for 2 weeks. And don't let it get cold, it will suffer big time.

Yes, temperature management is also a challenge if you are building a
lunar greenhouse, but let's assume that problem is handled.

Broadband "solar" spectra were unnecessary for my "Ki" plant. I used
a host of ordinary 60 watt lightbulbs in my computer room, with one
of them poised 1 foot away from the plant.

Lots of IR produced by those that the plant probably doesn't use
efficiently. I'm wondering what the minimum nighttime power
consumption could be at the optimum wavelengths and duty cycle.
Surviving with *zero* light isn't necessary, and there are probably
plants that just need a low duty cycle of light during the 2 week
night.

Now, as for raising tomatoes, I will bet you would need more "candle
power" for those little things.

Tomatoes, potatoes, beans, rice, whatever.

Thanks,
Dan DeLong

(Henry Spencer) wrote

Given a decent mascon map of the farside -- something we do not have


Perhaps there's a decent low-cost mission there. A small low orbiter
with a stable oscillator for "radio science," a higher satellite
for data relay while the low orbiter is over the far side. Ground
based receivers to calibrate the pair when they're in sight. Maybe
you could even do a GRACE-like mission if there were enough interest.

"Paul F. Dietz" wrote in message ...
Bill Bogen wrote:

Oxygen and aluminum, probably derived from
ilmenite readily available on the moon, are items useful for
space-based structures and propellant.

Deriving aluminum from ilmenite would be a neat trick.

Doh! Sorry, I was relying on faulty memory: anorthite would be a more
appropriate mineral.

In article ,
Allen Thomson wrote:
Given a decent mascon map of the farside -- something we do not have

Perhaps there's a decent low-cost mission there. A small low orbiter
with a stable oscillator for "radio science," a higher satellite
for data relay while the low orbiter is over the far side...

It's actually better to have a pair of small orbiters in very similar low
orbits, tracking each other and recording the data (the data volume is not
large) while over the farside. The *difference* in orbit perturbations
between two orbiters turns out to be a more sensitive probe of small-scale
gravity irregularities than absolute tracking data for a single orbiter.
The required tracking precision to yield greatly-improved maps is not high,
nowhere near what missions like GRACE achieve. See "Lunar Gravimetry",
Floberghagen, Kluwer Academic 2002.

Almost every major lunar-orbiter proposal for quite a while has included a
small subsatellite, deployed in lunar orbit, so that such intersatellite
tracking can be done for farside gravity measurements. (The Floberghagen
book is partly an account of studies done for ESA's proposed MORO orbiter,
which unfortunately failed to make the final cut in that round of science
mission selection.) The main exception is Japan's SELENE, which instead has
a high-altitude relay satellite for farside tracking of the main orbiter;
unfortunately, although SELENE is officially an approved project, Japan's
lunar program is far behind schedule and SELENE's launch date consequently
keeps slipping.

Yes, one could do quite a nice low-cost mission for this. The only fairly
costly part is getting to lunar orbit. The spacecraft engineering involved
for the actual science mission is not at all difficult.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

Dan DeLong wrote:

Just be
sure you give the plant a week of constant light before turning off the
lights for 2 weeks. And don't let it get cold, it will suffer big time.

Yes, temperature management is also a challenge if you are building a
lunar greenhouse, but let's assume that problem is handled.

If you have relatively good isolation and a large tank of water for
hydroponics, you might not need that much energy during the night to
keep it all warm, and as an added bonues you will be fighting a much
more gradual decline.

Lots of IR produced by those that the plant probably doesn't use
efficiently. I'm wondering what the minimum nighttime power
consumption could be at the optimum wavelengths and duty cycle.
Surviving with *zero* light isn't necessary, and there are probably
plants that just need a low duty cycle of light during the 2 week
night.

for a start, you can save 50% by switching from 24h days to 12h days.
you can get further savings emulating real days and a gradual autumn /
spring cycle.

next step is the fact that sodium growlamps (and i suppose one day
LED growlamps) are not just very efficent at converting electricty to
light but can also do such at frequencies where plants convert the highest
portion of it. So you need to deliver 4-6 times less light compared
to sunlight - and there are further ways for reducing it reflective
surfaces/separators to reduce loss, etc.

So you can get real earth-style growing with a fraction of 'full' power
and hibernate on much less. but I don't think plant hibernation of this
type and growing effects have been well studied.


Thanks,
Dan DeLong

--
Sander

+++ Out of cheese error +++