- Slides: 37
Electromagnetic Pulse as a Result of Nuclear Pulse Propulsion My study of Project Orion
Description n n Project Orion is a spacecraft designed to be launched by rapid nuclear bursts on the back end of it. A pusher plate causes it to be propelled forward. See picture below.
History of Orion n n Started by General Atomic in 1958. Funded by the Atomic Energy Committee at first. Funded mainly by the Air Force research center throughout it’s history. Most popular in 1962. Died because it was thought too radical in 1963.
Useful Tests from Orion n n There were many tests to try to protect the pusher plate against the nuclear blast. It was found if a plate is greased, it is protected. There were several tests that used conventional weapons to test theory. A model was built called the Hotrod. The Hotrod at first stayed on the launch pad. See the next slide.
Hot rod, too heavy. This is the Hot Rod that would not launch. It was found that it was too heavy, and stripped down to the bare essentials to attempt to launch it.
Hot Rod Stripped Down. This is the striped down Hot Rod. The next slide will test if this will launch or not.
Hot Rod Test
Test results n n n As you can see, the Hot Rod launched. It’s max height was about 100 m. The film inspired Van Braun to promote Orion. Van Braun was the principal creator in the liquid chemical rocket. The Hot Rod currently resides in the Smithsonian Institute. There is a theory that this chemical pulse propulsion might be a good way to get into space.
More about Orion Below is a diagram of how Orion would work, in a nutshell.
Forces on Orion The green circle in this diagram represents the pushing power of Orion. The yellow circle represents the explosion part of the Orion.
More Orion Pictures
Book on Project Orion
Pros of Orion n Could carry over 1000 tons of payload beyond the Earth and back. A Saturn V, the largest rocket ever built, could only carry a tenth of that into orbit, not traveling the greater distance to Saturn and back. Could potentially travel anywhere in the Solar System, to Mars, Jupiter, Saturn, Pluto, or anywhere really. Would have high ISP and Thrust.
Thrust n n The thrust of a rocket is it’s ability to accelerate. This is critical if you want to arrive at the destination faster, especially if it is nearby. Most chemical rockets have high thrust. Most newer efficient drives such as the Ion drive have very low thrust. Orion has a thrust similar to Chemical rockets, it can accelerate very fast.
ISP n n n ISP is a measure of how efficient a rocket is. It is measured in pounds thrust per pound propellant. A typical ISP for a chemical rocket is 300. That is not high enough to achieve orbit in one stage. Orion’s ISP is about 10, 000, which is about the same as the ultra-efficient Ion drive. Other forms of nuclear power are lower thrust and slightly lower ISP. Orion’s combination of Thrust and ISP is what allowed it to even be considered.
Cons n n n Pusher Plate stress Similar to H-bombs Fallout Misfire Electromagnetic Pulse(EMP) Space EMP
H-bomb Similarities n n n Hydrogen bombs use fission triggers to create fusion explosions. Orion pulse units are closely related to hydrogen bombs. Both use shaped nuclear charges Below is a picture of an Orion pulse unit.
Fallout n n Fallout is the radiation damage caused from the launch of a nuclear bomb. The fallout expected for an Orion launch is about 1% of the combined atmospheric nuclear testing from Russia and the United States It is estimated that it would kill 20 people randomly throughout the world. This would be reduced greatly if launched at the poles, as little radiation would return from space.
Why is fallout reduced at poles? The picture to the right shows Earth’s Magnetic Field lines. If launched near the Magnetic North Pole, particles are allowed to escape the earth, instead of being trapped by to fall to the Earth at a later date.
Need for Simulator n n As I approached the last problems, that of EMP, misfires, and space EMP, the need to do large numbers of calculations began to sink upon me. I decided to resolve this by programming a computer program to do all of this for me.
My simulator n n n Below is a snapshot of the simulator The simulator measures escape velocity, gravity, velocity, altitude, and mass of Orion spacecraft. This is what the simulator looks like when it is complete. Note that the velocity is greater than the escape velocity.
Process n n n Building the Orion simulator required a great deal of research. It is not perfect, but it is close enough to provide reasonable estimates to what I tested. The power figures were based on 200 bombs to 125, 000 ft. high. I found these to be off the optimum, so I made them optimum. It tests up to 800 bombs fired. This also required research on my part on the effects of gravity.
Formulas n Here a few formulas that played key roles in my simulator
Misfiring n n One of my major concerns was, what if a nuke misfires? To test this, I put a random factor of misfiring into my simulator, and had it abort if it ran into the ground. Remember, Orion was launched from 135 ft. The tests came back that it would take almost half of the nukes to fail to have Orion hit the ground, which is plenty safe in my view, as only les than 1% of nukes do not explode.
EMP n n n EMP is the effect of a nuclear bomb that tends to destroy electrical equipment for large areas. EMP has not been tested to any great degree, and there is no declassified formulas for estimating the area affected by nuclear bombs. EMP is actually a wave of electrons which will often be too many for electronics to hold, causing them to burn.
EMP(continued) n n n I used the probably false assumption that EMP power is linear based on size. I then took estimates for the amount of damage done, based off of declassified works. I based my figures by taking the Starfish Prime nuclear test of Project Dominic. There a 1. 4 megaton bomb launched 400 km above the ground damaged a radius of at least 1300 km. Note that the actual area is probably more. I calibrated these so that a number of 100 would destroy most electronics, and anything higher would be more destructive.
Formulas for EMP n These formulas were used to determine line of site, distance from a point on a circle based on arc length, and distance EMP traveled through the atmosphere.
Results from EMP testing n n n My results were saved into a file for later use. This file included the distance from ground 0, the most powerful strike of EMP, the number of EMP strikes in that area, and the altitude of the first strike of EMP. Note that this segment is the most useful because it is the cutoff for 100 level EMP strikes.
Results page §To the right is a sample of a part of the results. §Note that the entire file is much larger than this. §This piece was chosen because it is the point where the EMP is first considered dangerous. KEY Dis=Distance from ground 0 #= Num. of nukes Dam= Max. Damage index Alt=Altitude of max dam. Dis. # dam Alt. 269 725 103 30102 270 725 103 30102 271 725 102 30102 272 725 102 30102 273 725 101 30102 274 725 101 30102 275 725 100 30102 276 725 100 30102 277 725 99 30102 278 725 99 30102 279 725 98 30102 280 725 98 30102 281 725 97 30102 282 725 97 30102
Final results from EMP. n n n As the last page tells, there is a radius of about 276 km, or 170 miles that is affected significantly. Remember that this is probably not accurate, but is a good estimate. In reality, EMP changes with location, my results figured nothing based upon that. The only place on the globe that this would not cause significant damage is at the poles. These aren’t going to be launched from the continental US.
Space EMP n n Space EMP is the effect of nuclear weapons to damage satellites in low earth orbits. It could cause millions of dollars in damage, but would not effect the critical satellites for communications. It is caused when nuclear blasts take place in the Van Allen belts, or other magnetic field lines. Those in the Van Allen belts are the worst. The best test I could do was to measure the number of blasts taking place in or near the belts.
Space EMP results n n n I calculated that no blasts to take place in the Van Allen belts, if launched near the equator Although none were launched in the Van Allen belts, there would be some damage, esp. to low earth satellites, such as the ISS and Hubble. A good defense against this is to launch at either of the poles, which also reduces fallout and EMP.
Final Conclusion n As a whole, I would sate that Orion is very dangerous if not used properly, and probably would cause a great deal of damaged. However, I do not think that if it was launched at the poles it would cause much of this damage. I conclude that an Orion ground launch would be safe enough by my standards, if launched at the poles, and a way was found to reduce fallout even more, but should be a cooperative effort among all of the industrialized countries of the world.
Where it could be launched