Great discussion. Great minds think alike. In college I proposed two types of propulsion. The first is similar with monatomic hydrogen, except that I accelerated protons to near the speed of light. Working to maximize the MV. The other one was a matter/anti-matter propulsion. I laid out the potential production from CERN, etc. It wasn’t very long before they started collecting antimatter.
You may be right. Another invention disclosure was my effort to arrive at a propulsion system that would enable interstellar travel on a culturally feasible timeframe. I took Alpha Centauri as a target distance and 100 years as a maximum feasible time that an organization could cohere and persist to receive data from an interstellar probe. Then it came down to estimating the Isp needed for a reaction propulsion system. Without going into what peyote dreams got me there, I arrived at the use of Birkeland Rays, streams of million-electron-volt electrons, using relativity to give them relativistic momentum far in excess of their subrelativistic levels. MeV electrons are fairly easily made. As a suitable propellant source for electrons, I selected lithium. Hydrogen and helium would be low-density cryogens, not good candidates for a long-duration mission. Lithium had 3 electrons to offer when fully ionized, and the positive nuclei could be dumped overboard in a conventional ion engine. The net result was an Isp of about a million seconds.
But, at the end, I realized the dismal problem of all high-Isp systems: the deadweight of the power supply system...as power scales with the square of the exhaust velocity. This is why satellite ion propulsion systems are not operated at the highest Isp they are capable of performing: the reduction in propellant mass is more than overcome by the increase in power system mass.
I am scared shitless about antimatter. No containment system can be perfect, and a containment failure would be catastrophic for anything beyond specimen level. I don't want to be around when bright young fellows think they can make it by the gram. It is for similar reasons that I have never been seduced by the use of liquid ozone as an oxidizer (though I will admit to wondering how far one can cheat). Great gain in performance...but it is likely to detonate if you look at it the wrong way. Or the right way. Equal opportunity group suicide complex.
O3 sounds like fun to me. If I were younger, I would ride that candle.
Imagine if we could stabilize triatomic hydrogen in liquid form and combine it stabilized O3 in liquid form. That would be wild.
For humans interplanetary travel, I was pondering a high mass flow rate from orbit for the initial speed jump, followed by an ion engine.
The nuke power is a weight challenge. I was working with some folks on a small nuclear power plant for a diesel submarine conversion for the Navy, especially the Seals. But Boeing snatched that and the funding dried up. The key was a thermal electric conversion of 30%. Double the best I could find before them.
Ion engine: Accelerating electrons is easier, but my idea was to accelerate protons for the mass advantage.
Have you read the book "Ignition" by John Clark? It is a broad history of propellant behavior and lore from the Naval Air Rocket Test Station (NARTS) days. He deals with all the strange actors. Ozone was nothing to kid about. The only stable deal I read about was to mix it as a minor solute with oxygen difluoride. The raw stuff was just too touchy. Worse than nitroglycerine. (It will mix with liquid oxygen, stable at a low percentage. But the problem is that oxygen has a lower boiling point and will boil off faster. If the concentration rises above 30%, the mixture will stratify into ozone-poor and ozone-rich [90%] layers, and the high-ozone layer is unstable.)
Your interplanetary thrust / Isp split sounds reasonable. I'm more inclined toward nuclear thermal rocket propulsion. I'm fascinated with nuclear fission rockets, where the nuclear reactions are mingled with the propellant: much higher operational temperatures and specific impulse (about 4000 seconds), but problems with loss of unreacted fissionables. I diagnose the problem as there being too high a loading of fissionables in the thrust chamber, in order to maintain a critical mass. I think the critical neutron flux should be supplied mainly by a solid annular reactor, and only the consumable fissionable mass added to the propellant...but I hadn't gotten a Ph.D. in nuclear engineering. (That's retrospect. Part of not knowing what I needed to do in earlier life.) Sigh. But who knows what terrible mistakes my alternate life could have made? Not nice to second-guess God's plan.
Was Boeing interested in submarines at that point? Or did they just acquire the money? At one point in the 80s, Boeing was working on an oxygen-aluminum electric cell that worked on the oxygen dissolved in seawater, for submerged drone application (miniature unmanned submarine). The Navy never took it up...that I ever heard of. But 30% nuclear powerplant conversion efficiency is pretty good, considering most commercial nuke powerplants are maybe at 40%, and they are fine-tuned.
The trick to my Relativistic Electron Beam Engine Concept (REBEC) was obtaining a high momentum from an initial rest mass. To do the same trick with protons would require them to be accelerated to an energy of about 2 GeV. Difficult to do with massive equipment.
Interesting. I like NTP to get things moving, then switching to Ion. NTP is usually liquid hydrogen, but I was thinking about liquid water. I haven’t sorted out the proton acceleration challenge. But, as I always told people who said it was too hard or impossible: You just need to be more creative. Guaranteed discussion win and it is true. This is fun. I haven’t gotten into the weeds in a long time. Add this to your pondering: A train like ship where the propellant “cars” are launched into orbit and attached to the crewed spacecraft with the propulsion system.
I never got around to a PHD. I helped my friend get his. Gave him my organizational leadership methodology that worked for small teams to the largest organization. I usually fixed the problems the PHDs didn’t know they had.
Great discussion. Great minds think alike. In college I proposed two types of propulsion. The first is similar with monatomic hydrogen, except that I accelerated protons to near the speed of light. Working to maximize the MV. The other one was a matter/anti-matter propulsion. I laid out the potential production from CERN, etc. It wasn’t very long before they started collecting antimatter.
You may be right. Another invention disclosure was my effort to arrive at a propulsion system that would enable interstellar travel on a culturally feasible timeframe. I took Alpha Centauri as a target distance and 100 years as a maximum feasible time that an organization could cohere and persist to receive data from an interstellar probe. Then it came down to estimating the Isp needed for a reaction propulsion system. Without going into what peyote dreams got me there, I arrived at the use of Birkeland Rays, streams of million-electron-volt electrons, using relativity to give them relativistic momentum far in excess of their subrelativistic levels. MeV electrons are fairly easily made. As a suitable propellant source for electrons, I selected lithium. Hydrogen and helium would be low-density cryogens, not good candidates for a long-duration mission. Lithium had 3 electrons to offer when fully ionized, and the positive nuclei could be dumped overboard in a conventional ion engine. The net result was an Isp of about a million seconds.
But, at the end, I realized the dismal problem of all high-Isp systems: the deadweight of the power supply system...as power scales with the square of the exhaust velocity. This is why satellite ion propulsion systems are not operated at the highest Isp they are capable of performing: the reduction in propellant mass is more than overcome by the increase in power system mass.
I am scared shitless about antimatter. No containment system can be perfect, and a containment failure would be catastrophic for anything beyond specimen level. I don't want to be around when bright young fellows think they can make it by the gram. It is for similar reasons that I have never been seduced by the use of liquid ozone as an oxidizer (though I will admit to wondering how far one can cheat). Great gain in performance...but it is likely to detonate if you look at it the wrong way. Or the right way. Equal opportunity group suicide complex.
O3 sounds like fun to me. If I were younger, I would ride that candle.
Imagine if we could stabilize triatomic hydrogen in liquid form and combine it stabilized O3 in liquid form. That would be wild.
For humans interplanetary travel, I was pondering a high mass flow rate from orbit for the initial speed jump, followed by an ion engine.
The nuke power is a weight challenge. I was working with some folks on a small nuclear power plant for a diesel submarine conversion for the Navy, especially the Seals. But Boeing snatched that and the funding dried up. The key was a thermal electric conversion of 30%. Double the best I could find before them.
Ion engine: Accelerating electrons is easier, but my idea was to accelerate protons for the mass advantage.
Have you read the book "Ignition" by John Clark? It is a broad history of propellant behavior and lore from the Naval Air Rocket Test Station (NARTS) days. He deals with all the strange actors. Ozone was nothing to kid about. The only stable deal I read about was to mix it as a minor solute with oxygen difluoride. The raw stuff was just too touchy. Worse than nitroglycerine. (It will mix with liquid oxygen, stable at a low percentage. But the problem is that oxygen has a lower boiling point and will boil off faster. If the concentration rises above 30%, the mixture will stratify into ozone-poor and ozone-rich [90%] layers, and the high-ozone layer is unstable.)
Your interplanetary thrust / Isp split sounds reasonable. I'm more inclined toward nuclear thermal rocket propulsion. I'm fascinated with nuclear fission rockets, where the nuclear reactions are mingled with the propellant: much higher operational temperatures and specific impulse (about 4000 seconds), but problems with loss of unreacted fissionables. I diagnose the problem as there being too high a loading of fissionables in the thrust chamber, in order to maintain a critical mass. I think the critical neutron flux should be supplied mainly by a solid annular reactor, and only the consumable fissionable mass added to the propellant...but I hadn't gotten a Ph.D. in nuclear engineering. (That's retrospect. Part of not knowing what I needed to do in earlier life.) Sigh. But who knows what terrible mistakes my alternate life could have made? Not nice to second-guess God's plan.
Was Boeing interested in submarines at that point? Or did they just acquire the money? At one point in the 80s, Boeing was working on an oxygen-aluminum electric cell that worked on the oxygen dissolved in seawater, for submerged drone application (miniature unmanned submarine). The Navy never took it up...that I ever heard of. But 30% nuclear powerplant conversion efficiency is pretty good, considering most commercial nuke powerplants are maybe at 40%, and they are fine-tuned.
The trick to my Relativistic Electron Beam Engine Concept (REBEC) was obtaining a high momentum from an initial rest mass. To do the same trick with protons would require them to be accelerated to an energy of about 2 GeV. Difficult to do with massive equipment.
Were you referring to an NSWR propulsion system? Interesting.
Interesting. I like NTP to get things moving, then switching to Ion. NTP is usually liquid hydrogen, but I was thinking about liquid water. I haven’t sorted out the proton acceleration challenge. But, as I always told people who said it was too hard or impossible: You just need to be more creative. Guaranteed discussion win and it is true. This is fun. I haven’t gotten into the weeds in a long time. Add this to your pondering: A train like ship where the propellant “cars” are launched into orbit and attached to the crewed spacecraft with the propulsion system.
I never got around to a PHD. I helped my friend get his. Gave him my organizational leadership methodology that worked for small teams to the largest organization. I usually fixed the problems the PHDs didn’t know they had.