Long cables to power "ioncraft" to orbit?

[Robert Clark]

The ioncraft is a method proposed for decades for aircraft and
spacecraft propulsion:

Ioncraft.
http://www.markwilson.com/ioncraft/ioncraft.html

It works by ionizing the air by electrical charge thereby creating an
air flow between the electrodes, generating thrust. There are several
examples of these, called "lifters", made by amateurs:

The Lifters Experiments home page by Jean-Louis Naudin.
http://jnaudin.free.fr/lifters/main.htm

The problem with them is their power supplies are much heavy than the
weight they can lift. But why not leave the power supply on the ground
and connect it to the craft by long power cables?

There are carbon fibers that could support their own weight up to
hundreds of kilometer of altitude:

Carbon fiber (Dani Eder)
http://yarchive.net/space/exot­ic/carbon_fiber.html

And power transmission lines carry electrical power up to 250km away
at up to 600 megawatts of power:

Baltic-Cable.
http://www.answers.com/topic/baltic-cable?method=5

This page calculates you can lift 3.91 grams using 7.681 watts of
power or about a ratio of 1 to 2:

Lifter Theory.
http://jnaudin.free.fr/html/lftheory.htm

Then you could lift 1,000,000 kg using 2 gigawatts of power. The space
shuttle main engines produce a maximum of 37 million horsepower, or
27.6 gigawatts of power:

Boeing: Rocketdyne: Space Shuttle Main Engine Amazing Facts.
http://www.boeing.com/defense-space/space/propul/SSMEamaz.html

Then you could leave the large heavy engines and heavy fuel on the
ground and use it just to run electrical generators to drive the
ioncraft.
If the electrical cable was 4 cm wide made of carbon fiber, a 100km
long cable would have volume Pi*.02^2*100000 = 125.7m^3. At a density
of 1800 kg/m^3 for carbon fiber this would be 226,000 kg. Then twice
this number in kilowatts or 452 megawatts would be needed to support
the weight of the wire alone. You could have take this from the 10's of
gigawatts supplied to the ioncraft or have small versions of the lifter
drive all along the length of the power cable itself drawing off some
portion of the power to support each small portion of the cable.
The question: how much power would be lost by sending it along a 100km
long cable?


Bob Clark

 

[Uncle Al]

The ioncraft is a method proposed for decades for aircraft and
spacecraft propulsion: [snip]

It works by ionizing the air by electrical charge thereby creating an
air flow between the electrodes, generating thrust. There are several
examples of these, called "lifters", made by amateurs:

[snip crap]

Hey stooopid, thrust in this case varies as surface area but payload
varies as volume. The demo is bullshit when applied to the real world
product.

The problem with them is their power supplies are much heavy than the
weight they can lift. But why not leave the power supply on the ground
and connect it to the craft by long power cables?

[snip]

Dumber than a used tampon. Hey stooopid, rockets don't launch
straight up - not for long they don't. Getting 100 miles high is a
no-brainer. Scaled Composites mostly pulled it off ad hoc. Getting to
25,000 mph at 100 miles altitude is something else again.

 

[George Dishman]

The question: how much power would be lost by
sending it along a 100km long cable?

Choose your voltage. Divide power P by voltage V to
get current I. Loss is I^2 * R. You need to work
out R using the resistivity of the material and the
length. Remember to count both wires.

George

 

[Charles Jean]

Choose your voltage. Divide power P by voltage V to
get current I. Loss is I^2 * R. You need to work
out R using the resistivity of the material and the
length. Remember to count both wires.

George

I assume you will be running two cables for the power, a hot and a
return. How about insulation of the wires from each other? Is the
conductor here the carbon fiber itself or some metal? Then calculate:
a) the total mass of 100,000 ft. of the cables
b) the electrical resistance of 100,000 ft. of the the conductors
c) power loss through the conductors
d) temperature rise through the conductors


"There are known knowns. These are things that we know we know.
There are known unknowns. That is to say, there are some
things that we know we don't know. But there are also unknown
unknowns. These are things we don't know we don't know."
-Secretary of Defense Donald Rumsfeld

 

[Luhan Monat]

"There are known knowns. These are things that we know we know.
There are known unknowns. That is to say, there are some
things that we know we don't know. But there are also unknown
unknowns. These are things we don't know we don't know."
-Secretary of Defense Donald Rumsfeld

Rumsfeld must have taken EST. That was part of the course introduction.

 

[Jim Thompson]

Rumsfeld must have taken EST. That was part of the course introduction.

It's deja vu all over again ;-)

...Jim Thompson

 

[Rich Grise]

The problem with them is their power supplies are much heavy than the
weight they can lift. But why not leave the power supply on the ground and
connect it to the craft by long power cables?

Because 100 miles of copper power cable is even heavier?

Thanks,
Rich

 

[John Larkin]

Rumsfeld must have taken EST. That was part of the course introduction.

We had a lot of them here. We called them estholes:

"Yes, I'm standing on your face, and I'm wearing cleats, but if you
really want to be miserable, it's your problem."

John

 

[[email protected]]

Because 100 miles of copper power cable is even heavier?

I've been wondering how long it'll take before somebody states the
obvious.

Mati Meron | "When you argue with a fool,
[email protected] | chances are he is doing just the same"

 

[Ben Bradley]

Because 100 miles of copper power cable is even heavier?

And at Monster Cable(TM)(R) prices it's hugely expensive.

 

[[email protected]]

Because 100 miles of copper power cable is even heavier?

Thanks,
Rich

Aluminum is almost always used for high voltage power lines. This is
because of its lower weight:

Aluminium's Electrical Uses.
http://www.world-aluminium.org/applications/electrical/

At 2700 kg/m^3, it's weight is only 50% more than carbon fiber. So a 4
cm wide, 100km long aluminum cable would only weigh 340,000 kg. This
compares to 2 million kg for the space shuttle with solid rocket
boosters.
While carbon fiber is electrically conductive, you might want to use
aluminum for higher conductivity (lower power loss). Then you would use
carbon fiber to provide strength for the cable.


Bob Clark

 

[Ban]

Robert Clark wrote:
snip childish BS
I remember being 13yrs. old and discussing things like this with my
roommates at public school. It is a nice exercise being kids, but a grown up
person should switch on the probability check before x-posting to all these
NGs.

 

[bz]

[email protected] wrote in @f14g2000cwb.googlegroups.com:

Aluminum is almost always used for high voltage power lines. This is
because of its lower weight:

Aluminium's Electrical Uses.
http://www.world-aluminium.org/applications/electrical/

At 2700 kg/m^3, it's weight is only 50% more than carbon fiber. So a 4
cm wide, 100km long aluminum cable would only weigh 340,000 kg. This
compares to 2 million kg for the space shuttle with solid rocket
boosters.
While carbon fiber is electrically conductive, you might want to use
aluminum for higher conductivity (lower power loss). Then you would use
carbon fiber to provide strength for the cable.

How much current is going to flow? If those aluminum wires are 3 cm in
diameter, the resistance of two 100 km wires is going to be about 750 ohms.

Most of your power is going to end up heating your wire.




--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[GWBush]

Robert Clark wrote:
snip childish BS
I remember being 13yrs. old and discussing things like this with my
roommates at public school. It is a nice exercise being kids, but a grown up
person should switch on the probability check before x-posting to all these
NGs.

You are assuming that these peopleare grown-up and mature to start.

 

[Robert Clark]

[email protected] wrote in @f14g2000cwb.googlegroups.com:


How much current is going to flow? If those aluminum wires are 3 cm in
diameter, the resistance of two 100 km wires is going to be about 750 ohms.

Most of your power is going to end up heating your wire.

This page gives the resistance over 200 km for a 3 cm diameter cable
as only 7.9 ohms:

Electric Current.
"A high voltage transmission line has an aluminum cable of diameter
3.0cm, 200km long. What is the resistance of this cable? Solution:
The resistivity of aluminum is 2.8*10^(-8)ohm-m. the length of the
cable is 2*10^5m. The diameter of the cable is 3cm and its
cross-sectional area is equal to Pi*(d/2)^2 or 7.1*10^(-4) m^2.
Substituting these values into R = rL/A the resistance of the cable can
be determined.
R = (2.8*10^(-8)*2*10^5)/( 7.1*10^(-4)) = 7.9 ohms".
http://electron9.phys.utk.edu/phys136d/modules/m6/current.htm

For a wider cable the resistance will be less in proportion to the
cross-sectional area.


Bob Clark

 

[bz]

This page gives the resistance over 200 km for a 3 cm diameter cable
as only 7.9 ohms:

Electric Current.
"A high voltage transmission line has an aluminum cable of diameter
3.0cm, 200km long. What is the resistance of this cable? Solution:
The resistivity of aluminum is 2.8*10^(-8)ohm-m. the length of the
cable is 2*10^5m. The diameter of the cable is 3cm and its
cross-sectional area is equal to Pi*(d/2)^2 or 7.1*10^(-4) m^2.
Substituting these values into R = rL/A the resistance of the cable can
be determined.
R = (2.8*10^(-8)*2*10^5)/( 7.1*10^(-4)) = 7.9 ohms".
http://electron9.phys.utk.edu/phys136d/modules/m6/current.htm

For a wider cable the resistance will be less in proportion to the
cross-sectional area.

You are correct.

The discrepancy is in this figure: 2.8*10^(-8) ohm meter
Mathcad has 2.655 x 10^-6 ohm cm.

I used 2.655e-6 ohm meters!

I didn't look at the units closely enough.

I should have said 7.512 ohms for two 3 cm wires.


--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[Luhan Monat]

We had a lot of them here. We called them estholes:

"Yes, I'm standing on your face, and I'm wearing cleats, but if you
really want to be miserable, it's your problem."

Some friends of mine who did EST long before I did, already used the
term 'estholes' themselves.

 

[Ed Kyle]

Because 100 miles of copper power cable is even heavier?

Not to mention all of the untangling that would be
required after each launch.

- Ed Kyle

 

[Eric Chomko]

Charles Jean ([email protected]) wrote:
: On Tue, 17 May 2005 22:21:34 +0100, "George Dishman"

: >
: >: >
: >> The question: how much power would be lost by
: >> sending it along a 100km long cable?
: >
: >Choose your voltage. Divide power P by voltage V to
: >get current I. Loss is I^2 * R. You need to work
: >out R using the resistivity of the material and the
: >length. Remember to count both wires.
: >
: >George
: >


: I assume you will be running two cables for the power, a hot and a
: return. How about insulation of the wires from each other? Is the
: conductor here the carbon fiber itself or some metal? Then calculate:
: a) the total mass of 100,000 ft. of the cables
: b) the electrical resistance of 100,000 ft. of the the conductors
: c) power loss through the conductors
: d) temperature rise through the conductors


: "There are known knowns. These are things that we know we know.
: There are known unknowns. That is to say, there are some
: things that we know we don't know. But there are also unknown
: unknowns. These are things we don't know we don't know."
: -Secretary of Defense Donald Rumsfeld


Makes me think of the little passage from the Koran I think:

He who knows not and knows he knows not is simple, teach him,
He who knows and knows not he knows is asleep, awaken him,
He who knows not and knows not he knows not is a fool, shun him,
He who knows and knows he knows is a leader, follow him.

Eric

 

[Stephen Horgan]

The ioncraft is a method proposed for decades for aircraft and
spacecraft propulsion:

Ioncraft.
http://www.markwilson.com/ioncraft/ioncraft.html

It works by ionizing the air by electrical charge thereby creating an
air flow between the electrodes, generating thrust. There are several
examples of these, called "lifters", made by amateurs:

The Lifters Experiments home page by Jean-Louis Naudin.
http://jnaudin.free.fr/lifters/main.htm

The problem with them is their power supplies are much heavy than the
weight they can lift. But why not leave the power supply on the ground
and connect it to the craft by long power cables?

There are carbon fibers that could support their own weight up to
hundreds of kilometer of altitude:

Carbon fiber (Dani Eder)
http://yarchive.net/space/exot­ic/carbon_fiber.html

And power transmission lines carry electrical power up to 250km away
at up to 600 megawatts of power:

Baltic-Cable.
http://www.answers.com/topic/baltic-cable?method=5

This page calculates you can lift 3.91 grams using 7.681 watts of
power or about a ratio of 1 to 2:

Lifter Theory.
http://jnaudin.free.fr/html/lftheory.htm

Then you could lift 1,000,000 kg using 2 gigawatts of power. The space
shuttle main engines produce a maximum of 37 million horsepower, or
27.6 gigawatts of power:

Boeing: Rocketdyne: Space Shuttle Main Engine Amazing Facts.
http://www.boeing.com/defense-space/space/propul/SSMEamaz.html

Then you could leave the large heavy engines and heavy fuel on the
ground and use it just to run electrical generators to drive the
ioncraft.
If the electrical cable was 4 cm wide made of carbon fiber, a 100km
long cable would have volume Pi*.02^2*100000 = 125.7m^3. At a density
of 1800 kg/m^3 for carbon fiber this would be 226,000 kg. Then twice
this number in kilowatts or 452 megawatts would be needed to support
the weight of the wire alone. You could have take this from the 10's of
gigawatts supplied to the ioncraft or have small versions of the lifter
drive all along the length of the power cable itself drawing off some
portion of the power to support each small portion of the cable.
The question: how much power would be lost by sending it along a 100km
long cable?


Bob Clark

Leaving aside the engineering problems, you have to get to escape
velocity to make orbit and at altitude you run out of air to ionise.