I would like to ask the list about their thoughts about safety,
regards SPS (Solar Power satellites) and Nuclear Waste.
These good idea Solar Power Satellites aren't.
Reasons, the power is to be downlinked via microwave beam.
Attitude control thrusters jam, gyroscopes fail (in various manners),
electronics get fried.
These result (in the case of a downlink beam), drift.
There is no good reason, that I can think of, to risk, frying nearby
villages, towns, cities, aircraft in transit, with a wandering high
power microwave beam.
There have been radio and radar 'techs' that for some unknown reason,
failed to understand that they were irradiating themselves when they
were servicing such equipment during winter and noticed the warmth of
the beam or proximity to the equipement, and stayed there to get
warm. What's that? They are all dead? See if you can figure out why.
Nuke waste, solution to the high level waste problem.
Don't make it in the first place.
Thorium reactors are now a proven technology, several have been
constucted, and to my knowledge, all dismantled again.
The current setup for nuclear power generation is in a similar
situation as electric cars versus petroleum fueled cars.
Twenty years ago, the most wonderful creations were made. GMH in
Australia, produced several test models of electric car, when it
seemed like a good idea. Then, for some reason, NO-ONE can fathom,
they were banned, recalled and dismantled. Crushed. There is only one
left, it is in a musuem in the US, it has been disabled, and is not
permitted to be fixed. Go figure. The simple answer is, OIL ECONOMY.
Too much oil to make money from still, keep this for later. Now the
crap is hitting the fan and electric cars and hybrids, using beefed
up 20 year old technology are hitting the streets. ????? We could
have, should have, had all this back then, but aw no, too much oil
still.
Well, Nuclear power generation has a Uranium economy, not Thorium.
Thorium reactors are much more desirable than Uranium. The waste is
considered to be high level for approx. 50 years, not thousands.
Thorium reactors can not meltdown, they need a neutron particle beam
to keep the neutron density at a critical level as Thorium fission
does not produce enough neutrons on its own.
Turn off the beam, the reactor stops.
Thorium is more common than Uranium. Thorium can not be used to
produce fissile material, such as in a breeder reactor, (to my
knowledge, correct me if wrong). Bombs can not be made.
So, that's nice, what do we do with the mess we have now?
You do not put it on a rocket to send into space. Bad idea.
Rockets tend to explode every now and then.
Ever noticed that?
Mass accelerators, keep in mind that if you punch something into
space using wicked g's, it will no doubt ablate somewhat BEFORE it
gets into space.
Also, keep in mind the low level waste, hundreds of thousands of
tons, of liquid poison that is sitting in rusting tanks like oil
farms. The infrastructure is old and corroding. I don't hear much
about the fix for this one.
I have no solution for the current mess, but always thought synroc
was probably one of the better ideas.
Best idea is always to avoid the problem in first place, we are
beyond that, sadly.
Mass accelerators, magnetic/electric systems are techo and neat, but,
when gravity/kinetic/mass/recoil will do the same thing?
Huh? you say.
I see a use for this on the Moon, not Earth. Yet. Unless it's
military.
DO NOT DO THIS UNLESS YOU HAVE A LARGE EXPANSE OF OCEAN TO YOUR WEST.
Even as a test. What goes up comes down, usually to the west due to
Earth's rotation. Vertical transitions are a piece of cake, horizontal
transitions, you will need some mechanical assistance.
This IS dangerous, if it's not obvious.
If too much energy is imparted to the projectile, and it surpasses
the structural strength of the material used, it will shatter, or
explode.
There is a toy on the market that actually demonstates this effect
using rubber balls. The speeds produced by the rubber ball toy are
much safer but, still dangerous. I am no longer in possesion of the
formula for the exact calculation. One of those, Hard Drive crashes
that you will just never get the info again, because it is not
available for download.
That I am aware of.
Kevin Forbes, VK3UKF.
http://www.vk3ukf.com/
http://www.qsl.net/vk3ukf/
> These result (in the case of a downlink beam), drift.
>
> There is no good reason, that I can think of, to risk, frying nearby
> villages, towns, cities, aircraft in transit, with a wandering high
> power microwave beam.
Please go off and research SPS a bit more thoroughly before trying to discuss it with others. Just a bit of research would help you to understand why both your notion that a SPS beam could go off-target and remain a beam, or even if it could that it would "fry" entire cities are totally wrong for independent reasons. Also, I'm a bit skeptical that everybody who's ever enjoyed the warmth of a microwave beam is now dead. Can you back that up with authoritative sources? I had a friend who got into microwave beams intense enough to make the helmet on his head buzz, and he was still around many years later to describe it to me.
Regards,
Mike Combs
> I am of the belief that, SPS is unworkable, and extremely dangerous.
>
it remains to be seen whether it's workable economically.
> Reasons, the power is to be downlinked via microwave beam.
>
Yes, much like the "microwave beams" used by cell phones and cell
phone towers (although those are omnidirectional).
> Attitude control thrusters jam, gyroscopes fail (in various manners),
> electronics get fried.
>
> These result (in the case of a downlink beam), drift.
>
That depends -- some arrangements require an uplink beacon in order
for the downlink beam to remain focussed. That's not a matter of
programming; it's in the physics of the hardware itself (as I
understand it). So, if the beam were to drift or the uplink beacon
were to shut off, the beam would immediately become defocussed.
Other designs don't require that, but it doesn't matter, as we'll see
shortly...
> There is no good reason, that I can think of, to risk, frying nearby
> villages, towns, cities, aircraft in transit, with a wandering high
> power microwave beam.
>
Here's your big mistake: the assumption that a beam would "fry"
anything. The power density of a SPS beam is about half that of
natural sunlight. You get more fried going outside on a sunny day.
The only reason it's useful as a power beam is that this light (unlike
sunlight) is of a frequency that's easily converted into DC current
with a simple wire mesh.
So, if you have a pacemaker in your chest or steel plate in your head,
you would probably want to avoid wandering into the beam. Otherwise,
you probably wouldn't notice it at all; at most you'd feel a bit of
warmth, just as you do from sunlight. (This assuming you're in the
beam yet not under a rectenna; under the rectenna, there is little to
no extra RF energy at all.)
The biggest problem might be keeping birds from building their nests
on top of the rectenna arrays, where they would find it comfortably
warm on chilly days.
> There have been radio and radar 'techs' that for some unknown reason,
> failed to understand that they were irradiating themselves when they
> were servicing such equipment during winter and noticed the warmth of
> the beam or proximity to the equipement, and stayed there to get
> warm. What's that? They are all dead? See if you can figure out why.
>
Have there? Please name one (or otherwise cite a source).
> So, that's nice, what do we do with the mess we have now?
>
> You do not put it on a rocket to send into space. Bad idea.
> Rockets tend to explode every now and then.
> Ever noticed that?
>
Yes, but it's not hard to make a small containment vessel that can
survive explosion of the launcher.
The big problem with space-based waste disposal is the exorbitant
cost. (Of course that may change in the future, especially if we
start building power sats.)
> Mass accelerators, keep in mind that if you punch something into
> space using wicked g's, it will no doubt ablate somewhat BEFORE it
> gets into space.
>
Er.... the vessel will. That doesn't mean the contents will.
> Mass accelerators, magnetic/electric systems are techo and neat, but,
> when gravity/kinetic/mass/recoil will do the same thing?
>
> Huh? you say.
>
I do indeed. That statement makes no sense (it's not even
grammatical, and I can't see how to fix it).
Best,
- Joe
Joe Strout
joe@...
"Eternal vigilance is the price of liberty." -- Wendell Phillips
Kevin,
I suspect your concerns about SPS are somewhat valid, but mostly
misdirected. For instance, the crisis of Chernobyl won't be repeated in
America, because we don't build breeder reactors in a manner that allows
thermal runaway: If the control rods break down, our reactors cool, not
overheat. Similar safeguards can be built on an SPS microwave
transmitter: We'd make it's microwave transmitter *dependent* on
receiving a signal from its designated target. If it strays the
slightest off its mark, it would be incapable of slinging harmful
microwaves to an unintended target.
power?" If it cannot beam it to Earth, it must either divert it
elsewhere or overload itself. Well, both are valid options. If it
cannot find the Earth receiver target, it should have a backup aimed
elsewhere, e.g. at the Sun. If it cannot track the backup either, then
it is inoperative enough to justify its self-destruction by
overload/meltdown.
On Earth, Solar Power is very modular by nature... even to the degree
that it could help prevent centralized attacks. In space, it need not
be very different... an overloaded SPS could just blow fuses / trip
breakers between its major modules. EVA repair could, in theory, be
done by telepresence cybernauts.
- Twisty
> That still begs the question, "What does it do with the accumulated
> power?" If it cannot beam it to Earth, it must either divert it
> elsewhere or overload itself. Well, both are valid options. If it
> cannot find the Earth receiver target, it should have a backup aimed
> elsewhere, e.g. at the Sun. If it cannot track the backup either, then
> it is inoperative enough to justify its self-destruction by
> overload/meltdown.
>
the sun, connected to absolutely nothing, and they entirely fail to
overheat and melt, even though the power has nowhere to go. I'm not a
physicist, but my understanding is that without some sort of load, the
current simply stops (i.e., the panels stop generating electricity).
Similarly, I'm getting PV arrays on my roof in the next few weeks --
grid-tied, so these have to be shut off whenever there is a power
outage (so that the guys working on the power lines don't get zapped
with the electricity from my house). I asked the contractor what
happens to the power from the panels when the inverter is shut off.
He goggled at me a bit and then said it's no problem. Apparently it's
such a non-issue that they rarely even think about it.
Best,
- Joe
Joe Strout
joe@...
"The ultimate measure of a man is not where he stands in moments of
comfort, but where he stands at times of challenge and controversy."
-- Martin Luther King, Jr.
> I don't think it works like that. You can stick solar panels out in
> the sun, connected to absolutely nothing, and they entirely fail to
> overheat and melt, even though the power has nowhere to go. I'm not a
> physicist, but my understanding is that without some sort of load, the
> current simply stops (i.e., the panels stop generating electricity).
>
ultimately it is a question of numbers. Are the PVs silicon, TiO2, or
some new nanotube construct? Old "inefficient" silicon may have fixed
limits on DC capacity... but how do they hold up against the beta
radiation of the outer Van Allen belt, or solar plasma? When dealing
with megawatts, the physical states of matter must be effected to some
degree unless it gets distributed broadly enough that its conduits are
little stressed. (The North American grid is quite a juggling act of
bringing generators on and off, syncing AC phases, and trying its best
to meet demand. But AC is also more complex than DC, and would likely
be unnecessary on an SPS.) My point was simply that even an
over-ambitious design will not be irresponsible enough to level cities.
- Twisty
You know there has been a few scientist who have recommended using microwaves to keep warm. The logic is your not warming the whole house just your bodies.
Date: Friday, September 19, 2008, 10:53 AM
> These result (in the case of a downlink beam), drift.
>
> There is no good reason, that I can think of, to risk, frying nearby
> villages, towns, cities, aircraft in transit, with a wandering high
> power microwave beam.
Please go off and research SPS a bit more thoroughly before trying to discuss it with others. Just a bit of research would help you to understand why both your notion that a SPS beam could go off-target and remain a beam, or even if it could that it would "fry" entire cities are totally wrong for independent reasons. Also, I'm a bit skeptical that everybody who's ever enjoyed the warmth of a microwave beam is now dead. Can you back that up with authoritative sources? I had a friend who got into microwave beams intense enough to make the helmet on his head buzz, and he was still around many years later to describe it to me.
Regards,
Mike Combs
,,,and yet, none of you mentioned that a short wave radio transmitting from orbit to earth uses a particular frequency/wavelength that passes unabsorbed thru water(H2O), O2, N2 and CO2. W/o absorption, there can be NO heating or other destructive effects, so even if the beam wandered off focus, there would be no problem. Understand???
> Thorium reactors are now a proven technology, several have been
> constucted, and to my knowledge, all dismantled again.
>
> Well, Nuclear power generation has a Uranium economy, not Thorium.
>
> Thorium reactors are much more desirable than Uranium. The waste is
> considered to be high level for approx. 50 years, not thousands.
>
> Thorium reactors can not meltdown, they need a neutron particle
beam
> to keep the neutron density at a critical level as Thorium fission
> does not produce enough neutrons on its own.
>
> Turn off the beam, the reactor stops.
>
> Thorium is more common than Uranium. Thorium can not be used to
> produce fissile material, such as in a breeder reactor, (to my
> knowledge, correct me if wrong). Bombs can not be made.
>
> So, that's nice, what do we do with the mess we have now?
>
> You do not put it on a rocket to send into space. Bad idea.
> Rockets tend to explode every now and then.
> Ever noticed that?
>
> Mass accelerators, keep in mind that if you punch something into
> space using wicked g's, it will no doubt ablate somewhat BEFORE it
> gets into space.
>
> Also, keep in mind the low level waste, hundreds of thousands of
> tons, of liquid poison that is sitting in rusting tanks like oil
> farms. The infrastructure is old and corroding. I don't hear much
> about the fix for this one.
>
> I have no solution for the current mess, but always thought synroc
> was probably one of the better ideas.
>
> Best idea is always to avoid the problem in first place, we are
> beyond that, sadly.
>
> Mass accelerators, magnetic/electric systems are techo and neat,
but,
> when gravity/kinetic/mass/recoil will do the same thing?
>
> Huh? you say.
>
> I see a use for this on the Moon, not Earth. Yet. Unless it's
> military.
>
> DO NOT DO THIS UNLESS YOU HAVE A LARGE EXPANSE OF OCEAN TO YOUR
WEST.
> Even as a test. What goes up comes down, usually to the west due to
> Earth's rotation. Vertical transitions are a piece of cake,
horizontal
> transitions, you will need some mechanical assistance.
>
> This IS dangerous, if it's not obvious.
>
> If too much energy is imparted to the projectile, and it surpasses
> the structural strength of the material used, it will shatter, or
> explode.
>
> There is a toy on the market that actually demonstates this effect
> using rubber balls. The speeds produced by the rubber ball toy are
> much safer but, still dangerous. I am no longer in possesion of the
> formula for the exact calculation. One of those, Hard Drive crashes
> that you will just never get the info again, because it is not
> available for download.
> That I am aware of.
>
> Kevin Forbes, VK3UKF.
> http://www.vk3ukf.com/
> http://www.qsl.net/vk3ukf/
>
referenced. Just by doing a little research, I found that the world
is not as resistant to thorium reactors as you state. There are good
reasons for keeping uranium reactors around, namely for nuclear fuel
generation and for making weapons grade nukes. Ifother people have
them, we should too. I read not too long ago about a few
experimental thorium reactors, one I think in Texas and another in
Norway maybe. With us moving to the Moon, I think you'll see alot
more official research dedicated to the thorium fuel cycle.
Here are a couple good links:
http://selenianboondocks.blogspot.com/2006/05/thorium-reactors-for-
moon.html
http://thoriumenergy.blogspot.com/
Alexander DeClama
Luck is what happens when preparation meets opportunity - Seneca
http://potentiatenebrasrepellendi.blogspot.com/
Nec Aspera Terrent!
Hi All, I have worked in radio propergation, in my past life, for many
years.
switch on a microwave oven in the staff canteen. This was 30 years ago
when microwave ovens were new items. The person concerned had her had
cooked but this was from a faulty device.
I have known and worked with literaly hundreds of people who
themselves work on microwave systems all over the world. I do not know
of one case where they were affected by the microwave beam. Obviously
they took precautions and didn't stand directly in front of the
transmitters antenna, where power levels per square metre can be high.
At the receiving end, this is just not a problem.
In our propergation research, at cellular radio frequencies, we
adopted the Russian standards which were ten times lower than the
American standard and no ill effects were observed. I am talking about
the foremost British research establishment on radio propagation.
The experiments in Hawaii were interesting but this sort of
propergation happens all the time, well not all the time. It has been
quite evedent me that UHF and SHF microwave propergation is acheivable
over quite long distances for some time. I have witnested this for
various cellular systems where micro wave links are needed.
Propergation for GEO is doable with fairly low losses.
The other other objection for SBSS is the business plan. The foremost
objection is lauching to LEO and Starchaser's launch vehicles (of
which I have an interest) will do that at a reasonable cost. Then
geting to LEO, which usually means taking more propellant, however the
eMdrive will not require propellant so that cost is obviated.. ergo.
the the business plan will work. It will have similar costs to a
nuclear plant with no pollution and last a long time but that is a
political decision.
Best Wishes
Paul
Cape Canaveral is located on the East coast, not the West, because the
Earth spins toward its East, providing the added *motion vectors* (and
to a much smaller degree wind thrust) of *Coriolis Forces* in attaining
escape velocity. You'll notice a launching shuttle leans further East
over the Atlantic Ocean as it rises, not West over the populated
countryside.. While it's true that you raise an issue of some other
lift rather than rockets, the argument of Earth's Coriolis-related
motion vectors is still a major reason to choose East over West.
West coast location, such as Perth, Australia. While that would provide
a different rationale, e.g. where does the cable fall if snapped?, I
still question if the West coast is the answer: Most weather systems
tend to continue toward the East, as do motion vectors for the grounded
portion of a snapped cable... while local tropospheric weather and
gravity would make for a more random/downward pile.
But rockets and projectiles, if they want an improved chance of escape
velocity from Earth, point East.
- Twisty
> Of course, for a Space Elevator in Geosync, the argument is often
> for a
> West coast location, such as Perth, Australia. While that would
> provide
> a different rationale, e.g. where does the cable fall if snapped?
>
First we should answer: do we care? Modern space elevator designs
have a paper-thin cable. It would flutter more than fall, and if it
landed on your head while you were wearing a hat, you probably
wouldn't even notice.
were to hit the floating ribbon, and get it tangled up in the rotor.
> But rockets and projectiles, if they want an improved chance of escape
> velocity from Earth, point East.
>
True.
Best,
- Joe
Joe Strout
joe@...
Defend scientific integrity -- we're all better off when we seek the
truth honestly.
http://www.ucsusa.org/scientific_integrity/
Hi All again,
Try propagation as a replacement, sorry, a little dyslexic (if I can
spaell that!!).
Also eMdrive can get us from LEO to GEO in 36 days without additional
propellent.
Paul
1. Hi all. First post. Really glad to be here. Name's Andy. Space
isn't my day job - but it's my passion. Been interested in the same
things SSI's been interested in since I was three years old. I hope to
be an asset to the group. One of the things I hope to bring is space
and engineering knowledge.
why I think you should listen to anything I say. Going to take the
(possibly unwise) step of a short education summary:
-Bachelor of Science in Physics
-Engineer's Degree in Astronautics.
-Thesis work in high energy space power systems
-Day job - nuclear submarine officer
So, I don't work in the space industry professionally, but I've got a
space education, a broad engineering background, and specific
experience (~10 years) in a heavy industry. I don't know everything.
But I'm working hard to learn...
>
> That still begs the question, "What does it do with the accumulated
> power?" If it cannot beam it to Earth, it must either divert it
> elsewhere or overload itself. Well, both are valid options. If it
> cannot find the Earth receiver target, it should have a backup aimed
> elsewhere, e.g. at the Sun. If it cannot track the backup either,
then
> it is inoperative enough to justify its self-destruction by
> overload/meltdown.
>
Short answer: the accumulated power appears as heating of the array.
In typical modern spacecraft, this heat gets radiated off the back side
of the array to space.
Long answer:
This isn't really a problem. Or rather, it's a problem that has long
been solved. There is no "accumulated power", at least, not in the
electrical sense. The only time that an illuminated solar cell
generates electrical power is when attached to a closed electric
circuit. A solar cell is really like a battery that is energized only
when illuminated. The light sets up a voltage difference across the
cell. If you connect an electric device across that cell, then current
flows through the device to power it.
In an SPS this device would be (primarily) the microwave beam
generator. If the SPS cannot find the Earth reciever, you simply open
the circuit to the generator. Off goes the microwave beam. In this
case, what happens is that the array gets hotter than normal. This is
because the fraction of incoming power that is normally converted to
electrical power is not being converted. That energy needs to go
somewhere and it goes to heating up the cell.
The most common way to get rid of heat from a spacecraft's solar panel
is to radiate it to space. The back surface of most solar panels is
the perfect place to do this: there's plenty of surface area and the
back side of the array is not typically facing any large hot object
(like the sun) to interfere with heat rejection.
Andy P.
I do not have a degree in anything, and I
was able to understand your explanation.
Of course, if you're designing a powersat
or other system, the ability to explain it
to a guy like me isn't that important. But
if you're trying to, well, explain it to a
guy like me, such an ability matters a great
deal.
the first habitat.
Hi Andy and All,
spelling).
I wouldn't worry about credentials. However it's good to hear from
fellow engineers.
There are a number of other members who are not engineers / scientists
and it is good to hear their concerns about SBSS. It is all very well
for some of us to go ahead with these great plans but we also need to
listen to others worries about them and then try (if we can), to
ameriolate those concerns.
Paul
Hi Sailor and All,
get the idea across to those who are interested and the general public
so you are quite correct. It is not much good preaching to the
converted when the the general public has no idea what is happening
and what could happen in space.
How to reach the general public? Difficult one.
I think one way would to approch the science corrispondance of various
news papers and TV, internationaly. Then keep up the information route
to them but make sure it is accurate. If we (SSI) could get a data
base of all these science corrispndance in the media, then maybe elect
a member to liase with them all. Then, maybe we could begin to inform
the general pubil about the usefulness of space to them?
Paul
Great. Glad to hear it! Amen on seeing the first powersat.
--- In ssi_list@... "sailor.barsoom"