Fusion Rocket to the Moon

Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

On Feb 14, 7:56 pm, "Williamknowsbest" wrote:
Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

'Small detonatoin [sic] events amounting ot [sic] 60 tons of TNT are
totally
containable.' I would question that assertion, especially in the
context of something designed to fly and with 100 detonations
occurring per second. Most designs for fusion rockets, at least the
ones I have seen, have good deltaV numbers, allowing for high impulse
transfers, but low thrust. The problem of getting out of Earth's
gravity well is a formidable one, especially if you don't want to
spray the launch area with radioactives.

I think you have some good ideas here and something along these lines
will eventually be developed.
Hopefully research can be started (or has started already) within the
near future.

I would not be aiming for the Moon though. I feel there are far more
exciting places to visit.
I would suggest Mars, Europa and a Titan should be top of the list.

Williamknowsbest wrote:
Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .



They should call he first ship "The Jesus Christ" starship.

"Williamknowsbest" wrote in message
oups.com

Lo and behold, we still haven't the expertise nor the required
fly-by-rocket technology for safely getting ourselves to/from the deck
of that nasty moon. However, going for our moon's L1 makes perfect
sense, and it's entirely affordable and highly fly-by-rocket worthy of
such efforts being of station-keeping efficient to boot (just ask those
nice Clarke Station wizards).

Terraforming the moon (that's typically made double IR/FIR hotter than
hell and otherwise TBI lethal by day) is going to become so much easier
than our doing Mars, and that effort is going to directly benefit 100%
of humanity and that of eventually salvaging our badly failing
environment from the very get go. Once the LSE-CM/ISS by China is up
and running, as such the daunting task of terraforming that physically
dark and nasty sucker becomes doable, especially if mostly robotics and
a few brave humans are working within the relative safety of earthshine.
(it's technically so much easier staying warm than it is for keeping
your cool)

However, as long as we're in the process of losing our protective
magnetosphere at the ongoing demise of -.05%/year, as such that factor
alone could become the worse news to our frail DNA than whatever's
global warming us to death. With applied technology and spare energy
(also meaning your having spare loot), we can adapt ourselves to
surviving whatever's too hot, too cold or even too ocean rising wet.
However, cosmic and solar radiation is an entirely different matter, as
having spare energy simply isn't going to protect your frail DNA unless
it's in the form of being artificially shielded from ourpolluted sky,
that's no longer of sufficient density w/o magnetosphere in order to
defend yourself from the influx gauntlet of all that's becoming dark and
nasty (including the TBI worthy dosage that's derived from our very own
nearby moon).

What's so terribly taboo/wrong with relocating our moon to Earth's L1,
thus blocking off roughly 3.5% of our sun, as well as having gotten rid
of most of that rather pesky gravity/tidal force, plus having eliminated
the secondary IR/FIR that's also a touch global warming us to death at
the same time?

Wouldn't it also be a darn good thing, for getting that horrific salty
and physically dark old reactive orb of gamma and hard-X-rays a little
further away from us?

At having established four times the distance, we'd have roughly 1/16th
of that lethal dosage to deal with, and due to such efforts having
accomplished nearly zilch worth of centripetal related force is why we'd
have accomplished a mere fraction of what's pertaining to tidal energy
influx that's keeping us a little too extra warm (inside and out).

Establishing the LSE-CM/ISS (along with its tether dipole element that's
still capable of reaching to within 4r of Earth) is still perfectly
doable, and actually much better off for such being within the
protective shade of that moon, and otherwise getting full-earthshine
illuminated as being more than ideal for such a lunar space elevator and
interplanetary depot/gateway of efficient operations.

Where's the down side?
-
Brad Guth


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

On Feb 14, 3:54 pm, "Stephen Horgan" wrote:
On Feb 14, 7:56 pm, "Williamknowsbest" wrote:





Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

'Small detonatoin [sic] events amounting ot [sic] 60 tons of TNT are
totally
containable.' I would question that assertion, especially in the
context of something designed to fly and with 100 detonations
occurring per second. Most designs for fusion rockets, at least the
ones I have seen, have good deltaV numbers, allowing for high impulse
transfers, but low thrust. The problem of getting out of Earth's
gravity well is a formidable one, especially if you don't want to
spray the launch area with radioactives.- Hide quoted text -

- Show quoted text -

http://www.memagazine.org/backissues.../contexpl.html

The work on impulsive loads is largely classified and not studied in
the course work of most mechanical engineering and structural
engineering courses. However, since 9/11 that is changing. A
detailed understanding of the mechanics of impulsive forces - even
those known at the time of the construction of the World Trade Center
- may have been sufficient to save that structure from the crash of a
fully loaded airliner into both of the towers.

The reason for this information being classified is obvious. Anyone
with the knowledge of how to build a container for a nuclear explosion
can use that knowledge to create a reinforced shelter proof against an
atomic blast. But, the benefits of securing this sort of generally
useful knowledge is small compared to the long-term benefits of having
this knowledge.

Clearly knowing how to deflect an atomic bomb driven shockwave is not
the same sort of knowledge, which is now possessed by such nations as
North Korea and Pakistan, of creating nuclear weapons in the first
place. So, there should be a general review of such classified
literature in the modern age.

Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range. Such capacity dramatically increases the efficiency
of nuclear pulse propulsion, and creates spacecraft of unprecedented
capabilities.

While the moon is the first and simplest target of such a spacecraft,
since we have experience travelling there already, obviously owners of
such a spacecraft would not stop there, they would move across the
solar system taking stock of the resources of the place, in a manner
similar to Lewis and Clark in early US history, and like the USGS in
later times. A United Nations Solar System Survey (UNSSS) would
collect and correlate all information, and then through some sort of
solar system lease arrangement, provide for the development of
resources found there. The owners of the spacecraft technology and
production infrastructure, would benefit obviously since their
technology would be required to develop such resources. The rate of
import of raw materials from across the solar system by Earth, and the
value it creates to human industry, would set the costs and prices
involved in creating this transport infrastructure. This is well
beyond the science and engineering of such spacecraft, and in the end
gives capacity and cost targets.

A list of strategic materials is given here;

http://www.globalsecurity.org/milita...y/dod/dnsc.htm
http://www.defenseindustrydaily.com/...tals/index.php

So, use of metals important to industrial activity, metals like
Aluminum, Lead, Titanium, Copper, Nickel, Indium, and so forth, can be
examined in today's market and compared to the economic activity it
supports at the current price levels, and amounts can be estimated
going forward, assuming a global population of 10 billion living at
current US, Japanese and Western European standards of living, or
perhaps the top quartile of those populations.

One can do this by looking at USGS analysis of US use, and dividing it
out per capita.

http://minerals.usgs.gov/minerals/pubs/commodity/

For example Aluminum;

http://minerals.usgs.gov/minerals/pu...alumimcs07.pdf

The US used 2,300,000 metric tons of primary aluminum in 2006 (the
rest was recycled) which had a value of $6 billion ($1.20 per pound).
The US has 0.3 bilion people, so a population of 10 billion people
using aluminum at the same rate would require 76,700,000 metric tons
of production. This is a demand of 2.4 metric tons per second. This
would generate $200 billion per year in revenues.

A similar analysis of the world's other strategic material makes the
total imports add up to 3.2 metric tons per second.

An interplanetary infrastructure capable of producing a 2 meter
diameter conical shell 10 cm thick, with ceramic aerogel TPS coating,
and a MEMs based RCS, fired from launchers at the production site,
with metals layered to the appropriate thickness, should be able to
provide a 3.2 metric ton strategic material source disc, that would
start at 2 disc's landing in the US south west every minute to meet
current US needs, and expanding at 7% per year, to 60 disc's per
second, guided by GPS, to meet future world needs from US soil within
51 years.

Allocating 20% of the revenue to support off-world infrastructure,
that is, $2.4 billion per year rising to $80 billion per year with the
balance going to governments, marketers, and resellers. The economy
this supports rises from $12 trillion to $400 trillion in 51 years -
say from 2010 to 2061.

Large spacecraft of huge capacity can also orbit very large solar
power satellite networks that capture significant energy in GEO to
form IR laserbeams. These beams are sent to reforming satellites in
LEO which beam energy directly to many users on Earth's surface. Such
systems can also power industrial and propulsion systems throughout
cislunar space. Here is a representation of the LEO reformer segment

http://web.archive.org/web/199902091...tech/viz1.html

IR laser energy operating between 1,000 nm and 1,100 nm would
efficiently pump silicon panels at high intensity. Operation on the
ground would be limited to 400 W/m2 - about what the heating of the
Earth would be. But with nearly 100% conversion efficiency, and
operation in desert regions over 85% of the year, energy storage
requirements are minimized, and surface area per person is less than 5
m2 on the ground to meet all terrestrial energy needs. Using these
panels to produce hydrogen gas can also provide fuel for transports.

The United States currently spends $450 billion per year on its
primary energy needs. Again, allowing 20% to support the off-world
infrastructure, provides $90 bilion per year revenue to support the
powersat arrays. The balance going for taxes, and to support existing
marketers and resellers and processors of energy.

Growing at 7% per year over a 51 year period allows the US to export
hydrogen and IR radiation to other nations, this total rises to
$15,000 billion - 20% of which is $3,000 billion. The economic
activity supported by this activity rises from $12 trillion today to
$400 trillion by 2061.

At high altitudes above cloud layers, MEMs based hydrogen fueled
rocket arrays, can be augmented by high-intensity IR lasers beaming
energy to power electrostatically driven rocket arrays (built into the
same system) at 100,000 W/m2. Such vehicles would be capable of long-
range ballistic flight at low cost, as well as providing general
purpose access to space and beyond.

This may provide the technical means to expand economic activity well
beyond today's per capita levels as well as energy use.

Beyond MEMs rocket and general availability of ballistic transport and
interplanetary spaceflight, laser light sail technology gives us the
capacity to migrate to early interstellar transport systems in the
future beyond.

In this range of products, micro-nuclear explosions play an important
role in establishing the infrastructure described here as well as
expanding it. Laser light sails departing the solar system for nearby
star systems will very likely use nuclear pulse type propulsion
systems for local travel within the target star system until laser
based powersats are established.

Deployment of IR laser beaming powersats in orbit around distant stars
provide for easy two way interstellar commerce, with a growing number
of target stars.

On Feb 20, 1:16 am, wrote:
On Feb 14, 3:54 pm, "Stephen Horgan" wrote:



On Feb 14, 7:56 pm, "Williamknowsbest" wrote:

Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

'Small detonatoin [sic] events amounting ot [sic] 60 tons of TNT are
totally
containable.' I would question that assertion, especially in the
context of something designed to fly and with 100 detonations
occurring per second. Most designs for fusion rockets, at least the
ones I have seen, have good deltaV numbers, allowing for high impulse
transfers, but low thrust. The problem of getting out of Earth's
gravity well is a formidable one, especially if you don't want to
spray the launch area with radioactives.- Hide quoted text -

- Show quoted text -

http://www.memagazine.org/backissues.../features/cont...

The work on impulsive loads is largely classified and not studied in
the course work of most mechanical engineering and structural
engineering courses. However, since 9/11 that is changing. A
detailed understanding of the mechanics of impulsive forces - even
those known at the time of the construction of the World Trade Center
- may have been sufficient to save that structure from the crash of a
fully loaded airliner into both of the towers.

The reason for this information being classified is obvious. Anyone
with the knowledge of how to build a container for a nuclear explosion
can use that knowledge to create a reinforced shelter proof against an
atomic blast. But, the benefits of securing this sort of generally
useful knowledge is small compared to the long-term benefits of having
this knowledge.

Clearly knowing how to deflect an atomic bomb driven shockwave is not
the same sort of knowledge, which is now possessed by such nations as
North Korea and Pakistan, of creating nuclear weapons in the first
place. So, there should be a general review of such classified
literature in the modern age.

Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range. Such capacity dramatically increases the efficiency
of nuclear pulse propulsion, and creates spacecraft of unprecedented
capabilities.

While the moon is the first and simplest target of such a spacecraft,
since we have experience travelling there already, obviously owners of
such a spacecraft would not stop there, they would move across the
solar system taking stock of the resources of the place, in a manner
similar to Lewis and Clark in early US history, and like the USGS in
later times. A United Nations Solar System Survey (UNSSS) would
collect and correlate all information, and then through some sort of
solar system lease arrangement, provide for the development of
resources found there. The owners of the spacecraft technology and
production infrastructure, would benefit obviously since their
technology would be required to develop such resources. The rate of
import of raw materials from across the solar system by Earth, and the
value it creates to human industry, would set the costs and prices
involved in creating this transport infrastructure. This is well
beyond the science and engineering of such spacecraft, and in the end
gives capacity and cost targets.

A list of strategic materials is given here;

http://www.globalsecurity.org/milita...y/dod/dnsc.htm...

read more »

'Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range.'

It is not at all plain. And the design here calls for containment, not
partial containment, at 100x60 ton equivalent explosions per second.
It there any actual reference to support this? Why on Earth would a
United Nations Solar System Survey with de facto ownership of the
entire Solar System make for more efficient space development? Even if
the market was not more efficient why would any nation accept its
decisions?

On Feb 21, 3:15 pm, "Stephen Horgan" wrote:
On Feb 20, 1:16 wrote:

On Feb 14, 3:54 pm, "Stephen Horgan" wrote:

On Feb 14, 7:56 pm, "Williamknowsbest" wrote:

Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

'Small detonatoin [sic] events amounting ot [sic] 60 tons of TNT are
totally
containable.' I would question that assertion, especially in the
context of something designed to fly and with 100 detonations
occurring per second. Most designs for fusion rockets, at least the
ones I have seen, have good deltaV numbers, allowing for high impulse
transfers, but low thrust. The problem of getting out of Earth's
gravity well is a formidable one, especially if you don't want to
spray the launch area with radioactives.- Hide quoted text -

- Show quoted text -

http://www.memagazine.org/backissues.../features/cont...

The work on impulsive loads is largely classified and not studied in
the course work of most mechanical engineering and structural
engineering courses. However, since 9/11 that is changing. A
detailed understanding of the mechanics of impulsive forces - even
those known at the time of the construction of the World Trade Center
- may have been sufficient to save that structure from the crash of a
fully loaded airliner into both of the towers.

The reason for this information being classified is obvious. Anyone
with the knowledge of how to build a container for a nuclear explosion
can use that knowledge to create a reinforced shelter proof against an
atomic blast. But, the benefits of securing this sort of generally
useful knowledge is small compared to the long-term benefits of having
this knowledge.

Clearly knowing how to deflect an atomic bomb driven shockwave is not
the same sort of knowledge, which is now possessed by such nations as
North Korea and Pakistan, of creating nuclear weapons in the first
place. So, there should be a general review of such classified
literature in the modern age.

Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range. Such capacity dramatically increases the efficiency
of nuclear pulse propulsion, and creates spacecraft of unprecedented
capabilities.

While the moon is the first and simplest target of such a spacecraft,
since we have experience travelling there already, obviously owners of
such a spacecraft would not stop there, they would move across the
solar system taking stock of the resources of the place, in a manner
similar to Lewis and Clark in early US history, and like the USGS in
later times. A United Nations Solar System Survey (UNSSS) would
collect and correlate all information, and then through some sort of
solar system lease arrangement, provide for the development of
resources found there. The owners of the spacecraft technology and
production infrastructure, would benefit obviously since their
technology would be required to develop such resources. The rate of
import of raw materials from across the solar system by Earth, and the
value it creates to human industry, would set the costs and prices
involved in creating this transport infrastructure. This is well
beyond the science and engineering of such spacecraft, and in the end
gives capacity and cost targets.

A list of strategic materials is given here;

http://www.globalsecurity.org/milita...y/dod/dnsc.htm...

read more »

'Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range.'

It is not at all plain.

Why do you insist this is so?

And the design here calls for containment, not
partial containment,

Yes it does. A parabolic reflector is far more efficient than a
containment that thermalizes the shock and exhausts it through a
nozzle.


at 100x60 ton equivalent explosions per second.

Huge thrust, huge reflector.

It there any actual reference to support this?

What exactly references are you looking for? Thrust containment
references or market efficiency references?

Why on Earth would a
United Nations Solar System Survey with de facto ownership of the
entire Solar System make for more efficient space development?
the market was not more efficient why would any nation accept its
decisions?

What are you arguing? Markets are more efficient than what exactly?
You are confused here. You seem to think that establishing the
conditions for efficient markets somehow preclude the operation of
markets. Foolishness.

Fact is, free markets operate best in a specific context. In a
specific environment. This includes;

1) clear and fairly applied civil laws
2) open information sources
3) strong property laws fairly applied

None of these exist regarding the solar system today. There is no
generally accepted civil laws markets can rely on to enforce their
rights, or a court that can decide cases even if the laws existed or
an agency to enforce the decisions of such a legal body if it were to
exist. The basic resources of the solar system are largely unknown at
this point. It is at present illegal for nations, corporations, or
individuals to claim ownership of real property off-world.

In this environment there is no opportunity for a market to arise,
investments to be made, or resources to be developed. So your
assertion that markets would be more efficient is just plain missing
the point.


clear and fair rules, open publicly available information regarding
available resources and their value and fair and strong property laws
and a open system of exchange. None of this applies to the solar
system yet. The first step in creating a market is creating a solid
base of information, an clear

The development of this sort of thruster would transform life on
Earth! Each tube would lift up to 45,000 metric tons of deadweight
and clusters of up to 10 tubes would create vessels as large as any
that ply the oceans of the world today. More analysis below

On Feb 14, 11:01 pm, "steve"
wrote:
I think you have some good ideas here and something along these lines
will eventually be developed.
Hopefully research can be started (or has started already) within the
near future.

I would not be aiming for the Moon though. I feel there are far more
exciting places to visit.
I would suggest Mars, Europa and a Titan should be top of the list.

A ship with this capacity would be able to sail across the solar
system. We'd have constant gee out to about 30 million miles, with
only a 10% propellant fraction. Then we'd have to figure out how to
lower the acceleration to make efficient use of propellant beyond that
point.

Interplanetary navigation would be pretty easy. We'd just point the
ship toward the spot the planet will be when we get there. But of
course computer guidance systems will bring things within inches. of
where we want them.

It would be cool to get rid of the fissile material altogether.
Lithium-6 Deuteride is an interesting fuel. If we can compress a 65
mm diameter ball of the stuff massing some 112 grams into a tiny ball
some 3 mm in diameter, we could attain fusion of the material.

One way to achieve this is to subdivide the fusion LiD sphere into 12
similar parts and fire them at each other at a velocity of about 4 km/
sec. Accurate assembly like this will provide the neessary
compressive energy to cause the pellets to compress to achieve
fusion. A rail gun system would work to achieve this or a laser
sustained detonation rocket ablating plastic propellant attached to
the LiD would also work.

Firing the 12 components at each other at 20 km/sec so that the center
of the compressing assembly is moving away from the component
injectors at 18 km/sec or so, would allow the detonation to take place
well away from the injection assembly. A blast door in the pusher
plate synchronized with the injection event would operate to allow
entry of the compressing pellet but deflect the shock wave from the
fusion blast. A parabolioid of rotation thrust chamber would
collimate the blast and produce an effective 24,000 km/sec thrust from
the 112 gram pellet. Retrieving only 1 part in 1 million of the energy
from the escaping plasma would be sufficient to power the injectors.
Tapping a small portion of the exhaust energy would also power other
vehicle systems.

133 detonations per second is the speed a 4-cylinder engine idling at
2,000 rpm handles fuel and air. Assuming its not problem building a
system to handle LiD in this way, we can estimate the power and thrust
of the rocket.

2.4e+7 m/sec = Ve
133/sec * 0.112 kg = 14.9 kg/sec = mdot

F = mdot * Ve = 3.57e+8 N = 36.4 kTf

N=newtons
kTf = kilo-tonnes force!

This would be sufficient to lift a vehicle some 22 million pounds (10
kilo-tonnes) at 3.64 gees!

Throttling back to half this force would be sufficient to blast off at
1.82 gees! The vehicle accelerating some 8 m/sec every second it
rises into the sky when launched from Earth.

With 10% of the vehicle mass LiD nuclear fuel and an exhaust speed of
24,000 km/sec final velocity under ideal conditions would be

Vf = Ve * LN(1/(1-u))
= 2.4e+7 ( LN(1/(1-.1))
= 2.5e+6 m/sec

This is a final velocity of 2,529 km/sec. Divide this figure by four
to get a round trip top speed. That's 6.3e+5 m/sec - or 630 km/sec.
Earth escape speed is 11 km/sec.

Now, if we have a constant gee thrust over say 20 million miles (32
million km = 3.2e+10 m) to Mars at a certain point in time. Then,
half the distance is accelerating and half the distance is slowing.
So,

d = 1.6e+10 m = V^2 /(2*a)

And V = 6.25e+5

Solving for a;

a = V^2 (2*d) = (6.3e+5)^2 / (2*1.6e+10) = 12.48 m/sec/sec

This is 1.27 gees!

At this acceleration it would take 28 hours to fly to Mars.

Acelerating at 1/3 gee would be possible over this distance;

a = 9.82 / 3 = 3.27 m/s/s

D = V^2 / (2*a) = 630,000^2 / (2*3.27) = 60,626,272,900

That's 60.6 million km. A similar distance would be needed to slow
down at your destination, so, a journy of 121.2 million km could be
undertaken at this acceleration and not outrun the fuel capacity of
the ship. That's pretty much the inner solar system.

Jupiter ranges from 519 million km from Earth to 965 million km.
These are 'legs' of 259.5 million km to 482.5 million km. Taking the
longest of these we have 1/24th gee to make this distance at this
propellant fraction with this vehicle. Sufficient gee force to keep
things from floating around.

The 133 impulses per second drop to 2 impulses per second at these
lower gees. Some sort of shock absorber to smooth these out would be
desireable.

Another possibility would be to reduce the size of the impulse units
and increase the detonation rate. Or increase the size of the ship
and increase the detonation rate. But this would limit top gees.

This thruster would propel a 10,000 metric ton ship at 3.6 gees - it
could also propel a 20,000 metric ton ship at 1.8 gees.

Increasing detonation rate from 133 per second and operating a 500
cycles per seond - a 4 cylinder engine operating at 7500 rpm has this
many detonations per seond - would lift a 45,000 metric ton vessel at
3 gees, but operate at 7 impulses per second at 1/24th gee.

Once the basic thrust unit or tube were proven operable, it could be
configured in a variety of forms and attached to a variety of
airframes.

Clustering these units in groups of 5 to 10 would create
interplanetary vessels comparable in carrying capacity to today's
largest ships

The largest super-tankers operating at around 2 gees at 500 Hz
injection rate would require only 10 fusor tubes (2 groups of 5). A
container ship would require only 2 fusor tubes

Three satellites in GEOSYNCH orbit operating 2 tubes each at 133 Hz,
blowing in opposite directions, could power a laser system that would
provide 30x all today's power to the world. Operated at 1/30th
thrust, 32,000 tons of lithium deuteride delivered to each satellite
each year would provide the world's energy needs today.

Laser sustained propulsion systems could be powered from GEO and
provide global access to cislunar space. These vehicles would dock
with larger cruise vessels for rapid interplanetary transport.

Today's Ocean Going Vessels and their sizes


Name Ships Type Length Displacement

Knock Nevis 1 Supertanker 458 m 564,763
Batillus class 4 Supertanker 414 m 550,000
Esso Atlantic 2 Supertanker 406 m 516,000
Esso Pacific Supertanker 406 m 516,000
Emma Mærsk 3 Container 397 m 170,974
Estelle Mærsk Container 397 m 171,000
Eleonora Mærsk Container 397 m 171,000
Hellespont 4 Supertanker 380 m 234,006
Hellespont Tara Supertanker 380 m 234,006
Hellespont Alha Supertanker 380 m 234,006
Hellespont Metr Supertanker 380 m 234,006
Gudrun Mærsk 6 Container 367 m 97,933
Grete Mærsk Container 367 m 98,000
Gunvor Mærsk Container 367 m 98,000
Gjertrud Mærsk Container 367 m 98,000
Gerd Mærsk Container 367 m 98,000
Georg Mærsk Container 367 m 98,000
Genesis of the 2 Cruise ship 360 m 220,000
Genesis class Cruise ship 360 m 220,000
AS-Class Mærsk 6 Container 352 m 75,000
CS-Class Mærsk 8 Container 347 m 70,000
RMS Queen Mary 1 Ocean liner 345 m 148,528
Berge Stahl 1 Bulk cargo 343 m 364,768
Enterprise 1 Aircraft ca 342 m 93,500
Freedom of the 3 Cruise ship 339 m 154,407
Liberty of the Cruise ship 339 m 160,000
Independence of Cruise ship 339 m 160,000
E-Class Mærsk 6 Supertanker 333 m 159,187
Nimitz class 10 Aircraft ca 333 m 102,000
Ford class 3 Aircraft ca 332 m 100,000
Kitty Hawk 4 Aircraft ca 327 m 83,960
Forrestal 4 Aircraft ca 325 m 80,000
Midway class 3 Aircraft ca 306 m 45,000
Adm. Kuznetsov 2 Aircraft ca 302 m 67,000
Porte-Avions 2 Aircraft ca 283 m 75,000
Carrier Future 2 Aircraft ca 280 m 65,000
Lexington 2 Aircraft ca 270 m 50,000
Iowa class 4 Battleship 270 m 56,500
Shinano 1 Aircraft ca 266 m 71,890
Yamato 2 Battleship 263 m 72,000
Admiral 1 Battlecruis 262 m 45,200
Bismarck 2 Battleship 251 m 50,900
Norwegian Star Cruise Ship 294 m 91,000
Norwegian Dawn Cruise Ship 294 m 92,250
Norwegian Jewel Cruise Ship 294 m 92,000
Pride of Hawaii Cruise Ship 294 m 93,558

On Feb 22, 2:24 am, "Williamknowsbest" wrote:
On Feb 21, 3:15 pm, "Stephen Horgan" wrote:

On Feb 20, 1:16 wrote:

On Feb 14, 3:54 pm, "Stephen Horgan" wrote:

On Feb 14, 7:56 pm, "Williamknowsbest" wrote:

Nuclear pulse rockets have been proposed as a way to use directly the
energy available from nuclear reactions;

http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

But the amount of nuclear materials disposed of in the atmosphere
during a rocket's ascent is a problem with these devices. An
uncompressed critical mass of weapons grade plutonium is at least 10
kg. And 1,000 devices are needed to achieve orbit. So, 10 metric
tons of plutonium reaction products would have to be released into the
atmosphere for each flight. Clearly unacceptable.

The amount fissile needed to achieve criticality is inversely
proportional to the square of the density of the material. Since
shaped plastic explosives can compress plutonium to 3x its rest
density, critical mass is reduced to 1.1 kg per device. Reducing the
pollution of each flight by this level.

Density is a function of pressure, and the pressures achieved with
chemical explosives are limited.

Is there a way to increase pressure and therefore density?

Well, there are techniques that have been developed to initiate fusion
reactions in pellets of lithium deuteride. These techniques, ranging
form Zeta-pinch to particle beam compression to inertial compression
(firingpieces at high speeds toward one another) to laser beam
compression - can achieve pressures 3,000 times greater than can be
achieved by chemical explosives. This means that densities of 10,000x
can be contemplated.

When applied to fissile materials this means that the amounts of
materials can be reduced by a factor of 100 million - critical masses
as small as 100 micrograme may be possible in the limit using these
techniques. When system simplicity and ease of manufacture are taken
into account, factors of 400 to 2,000 seem very easily achieved using
Z-pinch technique

http://en.wikipedia.org/wiki/Z-pinch

This implies bomblets using as little as 3 milligrams to 63 milligrams
of fissionable material each. This translates to a release of 3 grams
to 63 grams of fission byproducts per 1000 pulse unit launch.

When these very small fissile devices are used as a primary trigger
for a Lithium-6/Deuteride secondary, a large fusion device can be
contemplated that has very little fissile emissions.

Increasing densities reduces fissile materials required. Replacing
the fissile material with some sort of anti-matter trigger would also
be possible - reducing the use of fissile materials to zero.

Some have reported that by scattering a positron off of a neutron
undergoing decay, anit-protons can be created with far less energy
than they otherwise might by direct creation. This provides total
conversion of mass to energy with only a small input of energy to
create the positron in the first place. This can be used as a sort of
desk top anti-proton generator and when used as an anti-matter spark
plug - sustains desktop fusion or detonation of fusion secondaries in
sequence.

In any event these devices are very small - in the 10 gram to 100 gram
range, and due to fundamental limits of inertial confinement systems
and their triggers - they are limited to 6 kT/kg yeild. About 60 ton
to 600 ton yield. that's 240 GJ to 2.4 TJ per device.

The exhaust speeds achieveable with this sort of device are well above
7,000 km/sec. A continuous fusion rocket is capable of no more than
24,000 km/sec exhaust speed.

Small detonatoin events amounting ot 60 tons of TNT are totally
containable. Impulse units containing 10 grams of fusion material in
a rocket operated at 100 detonations per second totally deflected by
thrust structure, has a propelant flow of 1 kg per second and an
exhaust speed of 7,000 km/sec. That's a thrust of 700,000 kgf - or
700 metric tons of force.

Accelerating at local gravity pluse 1/6th gee from Earth to Moon, with
turn-around halfway there, requires 1-1/6 gee at takeoff from Earth,
1/6th gee through transit, and 1/3rd gee at landing on the moon. The
vehicle detonates 62,516 pulse units massing 6.25 metric tons. The
vehicle masses 400 tons empty and carries 20 tons of pulse units.

It takes 8.5 hours to reach the moon from Earth, and 8.5 hours to
return at 1/6 gee. A total of 17 hours. With a 3.5 hours spent at
each end of the journey, the vehicle can provide daily flight service
to the moon. A fleet of four vehicles can provide a departure every 6
hours. Six vehicles provide spares and reasonable service times to
maintain this flight rate.

6AM 12 Noon 6PM Midnight

Six launch pads, a central control tower and dispatch, a ring of
support hangars, warehouses, and staging areas beyond that, road and
rail feeding into the center - a spaceport at each end of the journey
- one pad for every vehicle at either end.

A structural fraction of 20% - means that 80 tons are vehicle. Leaving
a payload of 320 tons - A total of 1280 tons per day to the moon and
back. At 350 kg per passenger, and 200 passengers per flight a total
of 120 tons per fight for passengers and 250 tons per flight for
cargo.

What could a fleet of six vehicles offering 4 flights per day to the
moon?

A ton of supplies will support 1 person on the moon for a year. So,
without any ability to recycle or make use of lunar resources - 1000
tons per day cargo supply rate could support 365,000 people on the
moon. A balanced allocation to growth and support would allow an
initial city of 100,000 be built in the first year, and support
100,000 tourists - with an average stay time of 4 days then, 200,000
tourists per year would visit the moon and use very little resources,
the remaining 165,000 inhabitants would live in 40,000 high end homes
built on a lunar housing development built over a 3 year period.

The Merrill Lynch World Wealth Report indicates that to maintain this
rate of demand for flights prices in the $100,000 per stay range, and
housing prices in the $10 million per unit range with daily use
charges for air, water, food and so forth. The tourists and luxury
home buyers help support the infrastructure for research and
development, and provide jobs for researcher extended families.

This is sort of the 1950s vision of Luna City - .

'Small detonatoin [sic] events amounting ot [sic] 60 tons of TNT are
totally
containable.' I would question that assertion, especially in the
context of something designed to fly and with 100 detonations
occurring per second. Most designs for fusion rockets, at least the
ones I have seen, have good deltaV numbers, allowing for high impulse
transfers, but low thrust. The problem of getting out of Earth's
gravity well is a formidable one, especially if you don't want to
spray the launch area with radioactives.- Hide quoted text -

- Show quoted text -

http://www.memagazine.org/backissues.../features/cont....

The work on impulsive loads is largely classified and not studied in
the course work of most mechanical engineering and structural
engineering courses. However, since 9/11 that is changing. A
detailed understanding of the mechanics of impulsive forces - even
those known at the time of the construction of the World Trade Center
- may have been sufficient to save that structure from the crash of a
fully loaded airliner into both of the towers.

The reason for this information being classified is obvious. Anyone
with the knowledge of how to build a container for a nuclear explosion
can use that knowledge to create a reinforced shelter proof against an
atomic blast. But, the benefits of securing this sort of generally
useful knowledge is small compared to the long-term benefits of having
this knowledge.

Clearly knowing how to deflect an atomic bomb driven shockwave is not
the same sort of knowledge, which is now possessed by such nations as
North Korea and Pakistan, of creating nuclear weapons in the first
place. So, there should be a general review of such classified
literature in the modern age.

Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range. Such capacity dramatically increases the efficiency
of nuclear pulse propulsion, and creates spacecraft of unprecedented
capabilities.

While the moon is the first and simplest target of such a spacecraft,
since we have experience travelling there already, obviously owners of
such a spacecraft would not stop there, they would move across the
solar system taking stock of the resources of the place, in a manner
similar to Lewis and Clark in early US history, and like the USGS in
later times. A United Nations Solar System Survey (UNSSS) would
collect and correlate all information, and then through some sort of
solar system lease arrangement, provide for the development of
resources found there. The owners of the spacecraft technology and
production infrastructure, would benefit obviously since their
technology would be required to develop such resources. The rate of
import of raw materials from across the solar system by Earth, and the
value it creates to human industry, would set the costs and prices
involved in creating this transport infrastructure. This is well
beyond the science and engineering of such spacecraft, and in the end
gives capacity and cost targets.

A list of strategic materials is given here;

http://www.globalsecurity.org/milita...y/dod/dnsc.htm...

read more »

'Plainly, we know how to deflect and partially contain small
explosions, and likely small nuclear explosions, in the 60 ton TNT
equivalent range.'

It is not at all plain.

Why do you insist this is so?

Because the assertion suggests that the scientific and engineering
knowledge required to do this exists. It does not, for example no
working examples exist.

And the design here calls for containment, not
partial containment,

Yes it does. A parabolic reflector is far more efficient than a
containment that thermalizes the shock and exhausts it through a
nozzle.

As opposed to disintegrating? Containment is required to achieve
fusion in any case.

at 100x60 ton equivalent explosions per second.

Huge thrust, huge reflector.

Huge means massive, and this is in the context of a contained fusion
reaction, which makes all of the other components huge and massive as
well.

It there any actual reference to support this?

What exactly references are you looking for? Thrust containment
references or market efficiency references?

That the engineering problems associated with this have been solved,
because I must have missed them.

Why on Earth would a
United Nations Solar System Survey with de facto ownership of the
entire Solar System make for more efficient space development?
the market was not more efficient why would any nation accept its
decisions?

What are you arguing? Markets are more efficient than what exactly?
You are confused here. You seem to think that establishing the
conditions for efficient markets somehow preclude the operation of
markets. Foolishness.

Markets are more efficient than the sort of central planning for
resource allocation that is being advocated. How does one body with
total control over the resources of the entire Solar System make for
any kind of a market?

Fact is, free markets operate best in a specific context. In a
specific environment. This includes;

1) clear and fairly applied civil laws
2) open information sources
3) strong property laws fairly applied

None of these exist regarding the solar system today.

Many nations on have clear and fairly applied civil laws, which would
apply to space activity in and around earth and the use of
extraterrestrial resources on earth. Information regarding solar
system resources is currently freely available and scientific
information of that type will probably continue to be. Information
relating to prospecting activity will probably be confidential, as
similar information is here on earth. Property laws already apply in
earth orbit and would develop further as exploitation of the Solar
System became a practical proposition.

There is no
generally accepted civil laws markets can rely on to enforce their
rights, or a court that can decide cases even if the laws existed or
an agency to enforce the decisions of such a legal body if it were to
exist. The basic resources of the solar system are largely unknown at
this point. It is at present illegal for nations, corporations, or
individuals to claim ownership of real property off-world.

Given that earth will be the hub of space activity for generations and
that offworld resources will largely be consumed on earth then civil
law and international agreements relating to space will apply.

In this environment there is no opportunity for a market to arise,
investments to be made, or resources to be developed. So your
assertion that markets would be more efficient is just plain missing
the point.

If several nations or companies develop the capability to mine NEAs
then a market in offworld minerals would establish very quickly.

clear and fair rules, open publicly available information regarding
available resources and their value and fair and strong property laws
and a open system of exchange. None of this applies to the solar
system yet. The first step in creating a market is creating a solid
base of information, an clear

Markets do not require that all information relating to commercial
activity be available, just the information that relates to exchanges.
The open system of exchange that would be used would probably be money.