reflecting sunlight onto the Moon?

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

You still hear people talk about them from time to time. I don't
think any new work has been done on making them real, though.

--
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis

(Geoffrey A. Landis) wrote

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

You still hear people talk about them from time to time. I don't
think any new work has been done on making them real, though.

Random notion, but perhaps a small-scale drop/bead radiator
experiment might be done outside ISS. Beads might be easier to
start with.

Allen Thomson wrote:
(Geoffrey A. Landis) wrote

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

You still hear people talk about them from time to time. I don't
think any new work has been done on making them real, though.

Random notion, but perhaps a small-scale drop/bead radiator
experiment might be done outside ISS. Beads might be easier to
start with.

Actually, even vomit comet results might be useful.

Geoffrey A. Landis wrote:

You still hear people talk about them from time to time. I don't
think any new work has been done on making them real, though.

There's work on liquid metal curtains in vacuum, not for use
as radiators, but as first walls for fusion reactors. The vapor
pressure of liquid lithium can be low enough for this to be
practical even with magnetic fusion reactors.

Paul

"Paul F. Dietz" wrote

There's work on liquid metal curtains in vacuum, not for use
as radiators, but as first walls for fusion reactors. The vapor
pressure of liquid lithium can be low enough for this to be
practical even with magnetic fusion reactors.

Li6 + n - He4 + H3, assuming the fusion reaction produces the n.

This can be cool if the fusion reaction uses tritium -- it's
essentially a breeder reactor -- but one should keep in mind
that tritium is to nuclear weapons design as MSG is to Chinese
restaurant cooking.

(Probably should go to alt.war.nuclear, but they know all this
stuff already.)

Allen Thomson wrote:

There's work on liquid metal curtains in vacuum, not for use
as radiators, but as first walls for fusion reactors. The vapor
pressure of liquid lithium can be low enough for this to be
practical even with magnetic fusion reactors.


Li6 + n - He4 + H3, assuming the fusion reaction produces the n.

Lithium blankets are an old idea, of course, but this idea was
to directly expose the liquid lithium to the vacuum.

This has several desirable effects:

(1) The lithium absorbs gas atoms, particularly hydrogen isotopes,
improving the quality of the plasma near the wall,

(2) The liquid is resistant to damage in disruptions,

(3) The liquid prevents the first wall from being damaged
by sputtering

(4) The liquid wall may improve plasma stability.

There are also schemes where thicker liquid lithium pistons are used
to magnetohydrodynamically compress an enclosed plasma, then
recover energy during an expansion stroke.

Paul

"Geoffrey A. Landis" wrote in message om...

Noting that power is very expensive in space, and very cheap on Earth,
it is very reasonable to suppose that the initial uses of power
beaming would be for space applications.


What kind of power are you talking about here? Actually solar power
in space is rather cheap. And the arrays to collect it are light and
easy to transport. Compared to other equipment, that is...

You never hear about the ISS or Hubble running out of electric juice.

Infrastructure to store and to harness power is expensive and/or
tricky.



--
__ "A good leader knows when it's best to ignore the __
('__` screams for help and focus on the bigger picture." '__`)
//6(6; ©OOL mmiv :^)^\\
`\_-/ http://home.t-online.de/home/ulrich....lmann/redbaron \-_/'

"Ool" wrote in message ...
"Geoffrey A. Landis" wrote:

Noting that power is very expensive in space, and very cheap on Earth,
it is very reasonable to suppose that the initial uses of power
beaming would be for space applications.

Ool replied:
What kind of power are you talking about here?

electrical power

Actually solar power in space is rather cheap.

Space solar arrays cost somewhere between 800 and 2000 dollars per
watt. The batteries to cover the eclipse power have similar cost.
That is *exclusive* of the transport cost.

And the arrays to collect it are light and
easy to transport. Compared to other equipment, that is...

Since you aren't quoting numbers here, I have no notion what you are
referring to.

You never hear about the ISS or Hubble running out of electric juice.

Do you have any notion how much the power systems for ISS and Hubble
cost?

Infrastructure to store and to harness power is expensive and/or
tricky.

Especially in space.

--
Geoffrey A. Landis
Any opinions expressed here are the opinions of the author, and should
not be considered official views of any agency or organization.
http://www.sff.net/people/geoffrey.landis

"Paul F. Dietz" wrote:

Joann Evans wrote:

If you really *must* do something like this, base these lasers in
stationary Earth orbit.

Good grief. Do you really think a laser in earth orbit is going to
be less than three times the cost of similar lasers on the ground?

Space is *expensive*. You don't do things there if you can avoid it.

"There is no law that says space must be expensive."

Arthur C. Clarke

Paul

Ian Stirling wrote in message ...
Allen Thomson wrote:
(Geoffrey A. Landis) wrote

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

You still hear people talk about them from time to time. I don't
think any new work has been done on making them real, though.

Random notion, but perhaps a small-scale drop/bead radiator
experiment might be done outside ISS. Beads might be easier to
start with.

Actually, even vomit comet results might be useful.

U Michigan students did that in 98, it appears. Or at least a spray
test related to such.

http://data.engin.umich.edu/umseds/kc135/kcldrkickoff/


/dps