Looking Back at Orion

Tom Kalbfus · 2016-08-31 09:12:20

interstellar-space-travel-concepts-adrian-mann-superorion.jpg?1327004035

Looking Back at Orion
by Paul Gilster on September 23, 2006

Whenever I think about Project Orion, I recall the ‘putt-putt’ experiments that tested the propulsion concept back in 1959. It was hardly an atomic spaceship, but the little putt-putt called ‘Hot Rod’ is as far as Orion ever got operationally. Using chemical explosives, Hot Rod rose 100 meters, a brief flight that nonetheless validated the idea that a spacecraft built around nuclear bombs, propellant and a pusher plate could be made to take stable flight.
An atomic spaceship. There was a time when the idea seemed to have interstellar possibilities. Freeman Dyson, a key figure in Orion, envisioned one version that used a copper pusher plate twenty kilometers in diameter. Driving the ship would be a nuclear arsenal of staggering proportions: 30 million nuclear bombs, each of which would explode 120 kilometers behind the vehicle at intervals of 1,000 seconds.
With a total acceleration time of five hundred years—and a comparable time for deceleration—this mammoth super-Orion would carry a colony of 20,000 Earth people to Alpha Centauri. Flight time: 1,800 years, making it a true multi-generation ship, where the distant descendants of the initial crew arrive at the target to make a new start for humanity. Later Dyson would ponder a pared down version that used 300,000 bombs to reach a final velocity of 10,000 kilometers per second, with arrival at Alpha Centauri in 130 years.
These days Project Orion’s interstellar capabilities seem vastly over-rated, even though its potential for travel to the outer Solar System was very real. Dyson himself now considers nuclear options unviable for missions to another star. When I was researching my book, I asked him his current views about Orion as a way to reach Alpha Centauri. Here’s a bit of what he said:

The Orion idea was exciting, but as far as interstellar trips are concerned, nuclear energy just doesn’t cut it… Youre using less than one percent of the mass with any kind of nuclear reaction whether it’s fission or fusion. The velocities you get are limited to much less than a tenth of lightspeed. Nuclear methods are great inside the solar system but not outside; in interstellar terms, they are not very interesting.
But what a story, and if you haven’t read George Dyson’s book about his father’s work, you’re missing out on a great experience. It’s Project Orion: The True Story of the Atomic Spaceship (New York: Henry Holt & Co., 2002). Online, the ever-reliable Anthony Kendall offers up a fine account of Orion. Here Kendall describes the vehicle, which would have dwarfed any rocket ever made:

A full-size Orion vehicle would have had a mass of 4,000 tons – about 40 times that of the Space Shuttle – and would include a “pusher plate” about 1-meter thick at the center. This solid mass of metal served to reflect the Orion craft away from the nuclear explosions, while at the same time protecting the passengers from the neutron radiation. The enormous shock absorbers between the pusher plate and the crew module would then distribute the 10,000 G’s of each nuclear blast to something much more comfortable for Orion’s passengers. In fact, an Orion launch would probably be much more comfortable than a conventional chemical rocket because of the sheer mass of the vehicle.
So vast were some Orion concepts that Ted Taylor, a weapons designer who became a guiding force behind the project, once considered installing a 4000-lb barber’s chair on the ship, thumbing his nose at the piddling chemical rocket designs that measured out payload in teaspoons. But of course, those chemical payloads got larger even as political currents made the nuclear option less realistic. The nuclear test ban treaty was but one of many blows that put an end to the program. Dyson talks about all this in Disturbing the Universe (New York: Harper and Row, 1979).
Be sure to read Kendall’s account for the overview, then George Dyson’s book, a volume I could hardly put down. And if you want to follow some of the interstellar references, start with Freeman Dyson’s paper “Interstellar Transport,” in Physics Today (October, 1968), pp. 41-45. The drama of Orion’s demise is told in Dyson’s “Death of a Project: Research Is Stopped on a System of Space Propulsion Which Broke All the Rules of the Political Game,” Science 149, No. 3680 (July 9, 1965), p. 141. And keep an eye on an Orion descendant called External Pulsed Plasma Propulsion, which may have much to teach us still.

http://www.centauri-dreams.org/?p=831
This could be of use in setting up Mars colonies, and on Missions to the Proxima Planet. I think it could establish a high enough velocity to plant a seeder colony on the Proxima planet with further development of Artificial Intelligence and Artificial Womb technology. if 0.1% of the speed of light can be achieved, and I believe that it can be with Orion nuclear pulse technology, then a mission to the Proxima Planet could be launched. Perhaps with some preliminaries to establish the nature of the planet. Humans can be raised on the planet with AI parents perhaps, eliminating the need to bring an O'Neill colony along, perhaps they can be raised on the planet's surface. If the planet's orbit takes it in front of Proxima, then that would establish its mass towards the more lower limit of 1.3 Earth masses, which means gravity would be just a shade higher than on Earth's surface. Hopefully there are some more Earthlike planets orbiting the other two stars in the Alpha Centauri System.

tahanson43206 · 2025-02-22 14:41:41

This post is reserved for an index to posts that may be contributed by NewMars members over time.

It would help greatly if members could include a one-line summary of the post that I could copy and paste into the index.

(th)

tahanson43206 · 2025-02-22 14:43:59

This post contains a copy of a conversation with Gemini (Google's search assistant) about a modern implementation of the Orion concept.

The subject has come back into view as a result of an initiative by PhotonBytes to consider what it would take to fly to Mars in 15 days.

Conversation with Gemini
Hi Gemini! Thank you for your assistance with previous questions! Today I have a search request for you. Many years ago, in the 1950's, there was a concept for space propulsion called Orion. I think this concept may be associated with Dr. Freeman Dyson. Nothing came of the idea, except for one critical data point. It was observed that a metal plate (called a pusher plate) would survive a nuclear blast. This was a critical confirmation that the Orion concept could be put into practice. The idea has come back into view in the context of the need for faster travel between the Earth and Mars that is allowed by Chemical propulsion. My request for you today is to see what you can find that might have been added to the knowledge base in the past 60 years. Of particular interest is anything you can find about how to handle EMP radiation, that is an unwelcome side effect of the Orion concept.
It's fascinating how the Project Orion concept continues to capture imaginations! You're right, it presents some incredible possibilities, along with some significant challenges. Here's a breakdown of what I found, with a focus on advancements since the 1950s, particularly regarding radiation and EMP:
Project Orion Revisited:
The Core Concept:
Project Orion's fundamental idea involves propelling a spacecraft by detonating nuclear explosions behind it. The "pusher plate" would absorb the force of these blasts, driving the vehicle forward.
Its potential for high thrust and high specific impulse makes it very attractive for deep-space missions, especially to Mars.
Challenges and Considerations:
Radiation:
The primary concern is, of course, the intense radiation produced by nuclear detonations. This includes both direct radiation and induced radioactivity.
Modern materials and shielding techniques have advanced significantly since the 1950s. This allows for more effective protection of the crew and sensitive equipment.
The data gathered from NASA's Artemis I mission is very important in this area. The data from the artemis 1 mission is being used to better understand radiation in deep space, and how to protect astronauts from it.
EMP (Electromagnetic Pulse):
Nuclear explosions generate powerful EMPs, which can damage or destroy electronic systems.
Advancements in electronic hardening and shielding are crucial for mitigating EMP effects. This includes:
Faraday cages: These conductive enclosures can block EMPs.
Hardened electronics: Components designed to withstand high levels of electromagnetic radiation.
Redundant systems: Having backup systems can ensure mission-critical functions continue even if some electronics are damaged.
Nuclear Test Ban Treaty:
The 1963 Partial Test Ban Treaty, which prohibits nuclear explosions in space, remains a major obstacle.
Modern Context:
Interest in Orion-like concepts has resurfaced due to the desire for faster deep-space travel.
Modern computer simulations and materials science allow for more accurate modeling and design of Orion-type spacecraft.
The advancement of fusion technology, could provide a much cleaner and more efficient version of the orion drive.
Key Advancements:
Radiation Shielding:
NASA's Artemis program is providing valuable data on radiation exposure in deep space, which is informing the development of more effective shielding.
Advanced materials, such as composites and specialized alloys, offer improved radiation protection.
EMP Protection:
The military and aerospace industries have made significant progress in hardening electronics against EMPs.
Nanomaterials and advanced shielding techniques are being explored to further enhance EMP protection.
Computational Modeling:
Powerful computers enable detailed simulations of nuclear explosions and their effects, allowing for more precise design and risk assessment.
In summary, while the challenges of radiation and EMP remain significant, advancements in materials science, electronics, and computational modeling have made the Orion concept more feasible.
Thank you for this comprehensive and detailed overview! Thanks for the reminder of the Nuclear Test Ban treaty. In the scenario we are considering, explosions would be very modest in size, but there would be a lot of them. In order for this advanced propulsion system to move forward, re-negotiation of the Nuclear Test Ban treaty would be needed. In any case, strict control of fuel elements would be essential. I'd like to take up a detail you kindly mentioned. We are familiar with the Faraday cage in the context of a room fitted with metal walls to prevent escape of electromagnetic radiation from the room or entry of outside radiation into the room. The question we have for you is: Can a Faraday shield prevent radiation to the front and sides, if there is an opening in the back for rocket exhaust?
You've hit upon a very important and complex aspect of applying Faraday cage principles to a system like a nuclear pulse propulsion spacecraft. Here's a breakdown of the challenges and considerations:
Faraday Cages and Openings:
Ideal Faraday Cage:
A perfect Faraday cage is a continuous, conductive enclosure. Any openings compromise its effectiveness.
The degree of compromise depends on the size and shape of the opening relative to the wavelength of the electromagnetic radiation being blocked.
The Rocket Exhaust Problem:
The rocket exhaust in an Orion-type drive creates a massive, unavoidable opening.
This opening would allow EMP and other forms of radiation to escape or enter.
Therefore, a perfect Faraday cage is impossible in this scenario.
Mitigation, Not Elimination:
The goal, then, becomes mitigation, not complete elimination, of EMP effects.
This involves a combination of strategies:
Localized Shielding:
Critical electronic systems could be housed in heavily shielded, localized Faraday cages within the spacecraft.
These internal cages would provide an extra layer of protection.
Redundancy:
Having redundant electronic systems can ensure that the spacecraft remains operational even if some systems are damaged by EMP.
Hardened Electronics:
Using electronic components designed to withstand high levels of electromagnetic radiation.
Directional Shielding:
It might be possible to design shielding that is more effective in the directions where the most intense EMP is expected. This would mean very heavy shielding on the sides, and front of the ship.
Pulse Shaping:
If it is possible to control the nature of the nuclear explosions, then it might be possible to shape the EMP pulse to reduce its most damaging frequencies.
Key Considerations:
Frequency Dependence:
The effectiveness of a Faraday shield varies with the frequency of the electromagnetic radiation.
Higher frequencies are generally easier to block.
Material Properties:
The conductivity and thickness of the shielding material are crucial.
Engineering Trade-offs:
Shielding adds weight, which reduces the performance of the spacecraft.
Engineers must balance the need for protection against the need for performance.
In Conclusion:
While a perfect Faraday cage is not feasible with a rocket exhaust, careful engineering and a combination of mitigation strategies can significantly reduce the impact of EMP.
The problem is extremely complex, and would require very advanced engineering solutions.
Sources and related content
How to Make a Faraday Cage & Why You Should - Mountain House
mountainhouse.com
Faraday Cage: What Is It? How Does It Work? - Gamry Instruments
www.gamry.com
Thank you for carefully considering the design of components for the space vessel. Please re-evaluate your answer with a focus upon protecting the Earth or satellites in orbit around the Earth from strong EMP radiation. We are thinking of operating the propulsion system midway between the Moon and Earth, so that distance reduces the strength of EMP. However, the question is whether a Faraday shield around the propulsion system would protect the Earth and it's satellites from radiation.
You've raised a critical point about the potential for collateral damage from a nuclear pulse propulsion system, even when operated at a significant distance from Earth. Here's a breakdown of the factors involved:
EMP Propagation in Space:
Unimpeded Propagation:
Unlike on Earth, where the atmosphere can absorb and scatter EMP, space offers virtually no resistance. This means that EMP can travel vast distances with minimal attenuation.
Therefore, even a relatively small nuclear detonation midway between the Earth and the Moon could generate an EMP that reaches Earth and its satellites.
Factors Affecting EMP Strength:
The yield of the nuclear device is the primary factor determining EMP strength.
The distance from the detonation to the target (Earth and satellites) also plays a crucial role.
The frequency characteristics of the EMP pulse can also influence its effects.
Faraday Shielding Limitations:
Directionality:
While a Faraday shield can attenuate EMP, it's most effective in directions where it provides a complete, conductive enclosure.
As discussed earlier, the rocket exhaust creates a significant opening, which would allow EMP to escape in that direction.
Even with directional shielding, it's extremely difficult to guarantee that no EMP would leak out.
Scale of the Problem:
The scale of the EMP generated by even small nuclear detonations is enormous.
Building a Faraday shield that could effectively contain such a powerful EMP would be a monumental engineering challenge.
Even if a good portion of the EMP was blocked, the portion that escapes could still be very damaging.
Secondary Radiation:
It is not only the EMP that is a problem. Nuclear explosions also produce other forms of radiation, that could also damage satellites, and harm the earth.
Protecting Earth and Satellites:
Mitigation Strategies:
Distance: Operating the propulsion system at a greater distance from Earth would help reduce EMP strength.
Yield Reduction: Minimizing the yield of the nuclear devices would also reduce EMP generation.
Pulse Shaping: If possible, shaping the EMP pulse to minimize its most damaging frequencies could be beneficial.
Satellite Hardening: Hardening satellites against EMP is essential. This includes shielding sensitive electronics and implementing redundant systems.
Operational Restrictions: Strict operational protocols would be needed to minimize the risk of accidental or uncontrolled detonations.
The Difficulty of Guaranteeing Protection:
It's important to acknowledge that it's virtually impossible to guarantee complete protection from EMP in this scenario.
Even with the most advanced shielding and mitigation measures, there would always be a risk of some level of damage.
In Conclusion:
While a Faraday shield can help mitigate EMP, it cannot provide complete protection.
Protecting Earth and its satellites would require a multi-layered approach, including distance, yield reduction, pulse shaping, satellite hardening, and strict operational controls.
Due to the nature of EMP, and other radiation emisions, there will always be a risk to satellites, and the earth.
Thank you for a helpful analysis and for your suggestions of items for study.. I'll now share our conversation with a small team. While I'm away, best wishes for similar success as you attempt to help your thousands of other customers.
You're very welcome! I'm glad I could provide some helpful insights. I understand you'll be sharing this with your team, and I wish you all the best in your discussions.
And thank you for your kind wishes. I'm always striving to assist users to the best of my ability. Have a productive meeting!

(th)

New Mars Forums

Announcement

#1 2016-08-31 09:12:20

Looking Back at Orion

#2 2025-02-22 14:41:41

Re: Looking Back at Orion

#3 2025-02-22 14:43:59

Re: Looking Back at Orion

Board footer