Let's Bring Back "Classic Orion" -- Nuclear Pulse Propulsion

John · Senior Member

Let's Bring Back "Classic Orion" -- Nuclear Pulse Propulsion

androbot2084 · Veteran Member

Yes I am proposing using a laser to detonate a pure fussion device. As far as radiological pollution goes new environmental impact reports will have to be filed but I am sure that the results will be far more optimistic than the environmental impact reports filed 50 years ago where the only clean bomb available was a fission ignited hydrogen bomb. Although those devices were 85 percent fusion they still polluted as much as a Hiroshima fission bomb because of the enormous size of the thermonuclear device.

There is no doubt that using a super laser to ignite small B-B size pellets would result in the most efficient burn and would be ideal for interstellar travel. But the joke is that all of these fusion projects depend on technology that takes about 50 years to develop. The Orion Project realizes its goals in a 10 year time frame which is to send a man almost anywhere in the solar system which is not only Mars but includes Saturn as well. This is imperative in our current economic and political climate where politicians demand results and will not tolerate delays and cost over runs. Also Orion takes a lower tech approach to spaceship construction because weight is no longer a factor so good old fashion steel can be used rather than exotic expensive metals. So the construction of an Orion spaceship is no more difficult than the construction of a nuclear submarine.

NUKE ROCKY44 · Senior Member

Well OK, sounds interesting so we're talking about a Clean Fusion Mini-Magorion EPP?

The company (Ralph Ewing & Dana Andrews) who are huge fans of any Orion are Andrews Space Inc. Seattle Wa.

As an addendum for John they are also the company that uses Ballute Reentry Technology. http://andrews-space.com/content-main.php?subsection=MTA0

Brice Cassinti wrote this in '03

The nuclear devices being considered
are considerably smaller. These devices are pellets in
the range from 15 cm down to 2 cm in diameter.
Detonation can occur using inertial confinement fusion
concepts or a high energy density trigger, such as
antiprotons. In inertial confinement fusion systems the
compression can be provided using laser beams or
particle beams.
Smith, has noted that it is more efficient to annihilate
antiprotons in a fissionable material than to annihilate
the antiprotons in the fusion fuel directly. Each
antiproton annihilation will result in at least one fission
reaction and the energy from the fission reaction can be
used to drive the fusion reaction in the pellet.
The energy transferred from the fission products is
considerably higher than the energy transferred from the
annihilation products. The propulsion systems proposed
by Smith all require some pellet compression of the
fission and fusion fuel for the reactions to proceed
efficiently.
It may be possible to remove the compression system
entirely by combining antiprotons and the transient
magnetic fields generated during the annihilation.
Finally, it is also possible to include fissionable material
that can boost the performance of a fusion propulsion system.

Advances in nuclear pulse propulsion over the last
several decades have been considerable. The earliest
proposals considered using critical mass nuclear
weapons in external and internal pulse systems.
Later concepts examined compression schemes for
inertial confinement fusion to ignite small pellets
without the use of fissionable material. Currently
investigators are looking at triggering fusion reactions
without significant compression using antiprotons.
Other investigators have also looked at hybrid
fission/fusion systems and even completely contained
nuclear pulse systems are again being considered.

PS. inertial confinement schemes require huge laser power. How much mass are
we talking about 'cause some military laser platforms require a 747 ??

Mucho big amigos.

-- Edited by NUKE ROCKY44 on Thursday 18th of February 2010 07:30:51 AM

John · Senior Member

Dr. Terry Kammash of the University of Michigan put together a collection of papers titled "Fusion Energy in Space Propulsion" that maybe a little dated but not much since little has happened since 1995. But, the anti-matter detornated ICF seemed to be the most promising. It is a significantly less massive that using lasers and a lot less massive than magnetic confinement fusion. Cassinti's paper is in the collection.

These are all long term research issues. At one time a was optimistic that we might move to such systems fairly early (maybe 20 or 30 years). But, I think it to be likely to be longer term than that.

Actually mature nuclear/VASIMR systems could be very attractive. This won't be early version but is a powerful space nuclear reactor driving a hydrogen based system could have fairly good thrust at the lower specfic impulse and great propellant efficiency. Consider the following peak specific impluses:

Chemical (LH2/LOX) 450 sec

Nuclear Thermal Propulsion (solid core) 900 sec - 1200 sec

VASIMR 30,000 sec

Fusion 600,000 sec

Total Mass Conversion 30,000,000 sec

The jump to VASIMR is a big jump up from chemical and when you consider the size of the fusion vehicles and the remaining development, it is a very attactive next step.

Bruce, thanks for the link on ballute technology.

androbot2084 · Veteran Member

There is no doubt about that the 600,000 sec Orion is a quantum leap in technology that skips all of the intermediate steps and defies common sense with its you have to learn to fly before you walk philosophy and promises manned missions to Saturn by 1970. Yet Orion can get away with these claims because it relies on existing technology. The reason why aerospace engineers insist on a step by step aproach is that they fear that if technology that is too far advanced is proposed like anti-matter annihilation it will never mature in time to meet the goals of the project so it is more important to set more reasonable goals. But all of this does not apply to Orion because the propulsion is so powerful that saving weight is no longer a consideration and exotic alloys are not needed but rather steel. I even wonder if cyrogenics were needed and had atomic bombs been available during the 1930's could we have sent a man to the moon if all we had were compressed gas cylinders?

So I am assuming that the technology exists today to operate Orion in a much cleaner and less polluting manner without relying on a lot of exotic technology like magnetic rocket nozzles that may be decades in the future so we can attain the goal of a safe manned mission to Saturn in this decade without breaking the bank.

John · Senior Member

I think you have to be careful in mixing the "Orion" of Taylor/Dyson (NPP) that used actual nuclear bombs (of special nature) to propel a craft with a giant plate and shock absorber systems specific impulse to a laser (or antimatter) fusion system (LFP). The later is far more efficient in using the energy released. On the other hand I don't know just how well it would work in the atmosphere. NPP doesn't require fundamental advances but it almost has to be launched from the ground up using low-yield nuclear explosions. How else could we get it in orbit?

My view is that for interplanetary travel the VASIMR propulsion is closer at hand in terms of cost to develop and time to develop. With a small nuclear energy source could be a leap ahead in space travel. We can leave it at this point for now. I sure that more discussion will follow.

Philipum · Veteran Member

John wrote:

I think you have to be careful in mixing the "Orion" of Taylor/Dyson (NPP) that used actual nuclear bombs (of special nature) to propel a craft with a giant plate and shock absorber systems specific impulse to a laser (or antimatter) fusion system (LFP). The later is far more efficient in using the energy released. On the other hand I don't know just how well it would work in the atmosphere.

Hi everybody. Androbot's idea, I think, was to use a laser to ignite big nuclear fusion bombs. It would be great ! However, like many new ideas, unfortunately, it probably wouldn't work, perhaps for several reasons, but a least for the one quoted above: a laser (or an anti-proton beam) shooting through meters of atmosphere will ignite the atmosphere, not the bomb. There may be a way around it... keep thinking ! confuse

androbot2084 · Veteran Member

I think Philipum hit the nail on the head as far as my idea goes which is to ignite big nuclear fusion bombs and perhaps smaller bombs but to avoid for now the attempt to ignite small pellets. Of course any object in the trajectory of a laser beam is a potential target and that may include the atmosphere however most laser systems use multiple lasers so that the trajectories end up converging only on one point which is the target where the lasers are aimed at. Also ignition is designed only to occur at the target because there is simply not enough energy from a single laser to achieve ignition. In designing robotically positioned laser systems accuracy and repeatability are the important factors with accuracy being being how close to the target we can get and repeatabilty being the ability to repeat our accuracy each time the laser is fired. Also frequency is an important goal and at the present it takes n amount of seconds to charge and fire the laser when the real goal is to operate the laser n times each second which is a magnitude beyond are capability.

So hopefully by using bigger bombs rather than small pellets it will be easier to achieve the goal of harnessing fusion power with today's technology and the only major technological hurdle should be designing more effective shock absorber systems which I propose a solution should be to incorporate shock absorbers along the entire 700 foot boom of the ship so that the entire ship goes into a robotic extension and retraction.

NUKE ROCKY44 · Senior Member

For me this issue is best handled with sober science and testing.

History:

HANE shots occurred by both Russia and the US in 50's & 60's in the exoatmospheric environment the highest was at an altitude of 540 km (335.5 mi). The Partial Test Ban Treaty was passed ending atmospheric and exoatmospheric nuclear tests. The Outer Space Treaty of 1967 banned the stationing and use of nuclear weapons in space.

My take is that if you're interested in this science it's best to use words like pulse not bombs. I would suggest triggering pulse devices can be achieved with current and nearer term technology at least for fusion devices.

Testing scenarios would need to establish a scientific rather than military purpose in space where the relevant international partners be involved.

Establish strict in-space operations to designate an "In Space Nuclear Pulse Test Site" this maybe one of the 5 Lagrange points some of which are occupied with other tests and experiments. Or it could involve a designated orbit.

Without some clear definition on how in space nuclear pulse science is conducted it will be difficult to get more space enthusiasts to look at this technology. (ex. EMP disruption).

NASA crashes stuff and explodes stuff on moon/meteors so what's wrong with testing nuclear pulse devices?

So yea, if anyone has an abstract/paper dealing with these issues pass it on to us.

-- Edited by NUKE ROCKY44 on Thursday 25th of February 2010 09:59:28 PM

John · Senior Member

I think Philipum hit the nail on the head as far as my idea goes which is to ignite big nuclear fusion bombs and perhaps smaller bombs but to avoid for now the attempt to ignite small pellets.

I really don't think that making the bomb (err nuclear pluse device) the target of a laser is going to be the solution to laser fusion. Only one part of the problem is hitting the pellet. Even when you get a "hit" getting the yield above breakeven is a lot of the problem.

The other issue that Teller-Ulam device has fission and fusion processes intimantely intertwined. So if you are proposing to replace the primary with a large fusion pellet which will the drive the rest of the device you still have the fisson of the "spark plug" which is a fission device. So you are will going to have some fission yield.

What it might allow you to do would be to down size the device in yield to levels that might allow for smaller space vehicles. I say might because the are some things I don't have confidence in about exactly what it would take to make a "spark plug" function. (And, if I really "knew" I wouldn't be discussing it here. smile

) That is could a compact fusion pellet drive fission in a very small fissile mass well below that achieved with chemical explosives? Also, you have to consider the radioactivity induced by all of the fusion neutrons flying around and the left over tritium released. But if the idea of very low-yield NPDs turns out to be feasible than we might avoid an earth based "blast off" and limit the use to space.

androbot2084 · Veteran Member

Certainly when igniting small pellets to produce fusion power like at the National Ignition Facility in Livermore California you can get away with not calling it a bomb because the explosion is so small it is more like an atomic fire cracker and besides everything is contained and hidden not only by the building which houses the facility but by all the techno mumbo jumbo which the average person cannot understand. Unfortunately this technology is still in the experimental stages and has not yet been proven to work.

However the Orion project is out in the open and its external combustion engine is plainly visible and anyone with any common sense after seeing the first Orion launch will be able to tell that this spaceship is powered by atomic explosions as a result of using atomic bombs. So what we have is a public relations nightmare because the idea will appear insane not that it wouldn't work but rather that we might consider doing it.

Unfortunately Orion technology is our only hope for space colonization because only Orion can lift millions of tons of payload into orbit and build badly needed infrusructure such as solar panels in orbit around the sun and Helium 3 mining on the moon so that we can have electric and hydrogen powered cars. And only Orion technology can produce the fusion power that is so badly needed for the worlds energy demands and if that means creating a Dyson sphere with a diameter of 2 miles wide in order to contain the atomic explosions why should our limited minds stop us if the technology exists to build these vast structures?

However you are right that Orion should not be called a bomb even if it works just like a bomb. Is the Sun considered to be a bomb? Theoretically the Sun can resemble the most destructive device imagineable yet because we are so far away from it the effects of solar radiation are rather benign. And for that matter a passenger jet aircraft can be considered a bomb