Pulsar Fusion Rocket Has Working Components

22 thoughts on “Pulsar Fusion Rocket Has Working Components”

1. As difficult as the primary problem is, why are they wasting resources developing chemical rockets? Why not let Starship solve the first mile problem? It has to be cheaper than what they are proposing.

   • I’m purely guessing they don’t want to assume, or be reliant on, anything that others are trying to do. Even SpaceX strongly believes in vertical integration.

     Given the current situation regarding space access (Ariane 5 was retired before Ariane 6 was operational, ULA’s customers [including SNC and their DreamChaser] are waiting for issues with Vulcan’s upper stage *and* BE-4 engines to be resolved, and Blue Origin needs more flight experience with those same engines before [already late] New Glenn can hope to fly…and Starship isn’t nearly there yet either, despite having gotten some daylight under it.), that may be a wise tactic.

2. I’ll take laboratory results and the hours I spent chatting with Richard Dinan (Pulsar’s CEO) in said laboratory over the rants of online experts any day.

   I’ve always been inclined to believe people who offer me a lot of transparency. I’m getting this transparency from Pulsar, and we’ll see what actually happens in the next four years.

   Thanks so much for posting this story!

   • You probably would have believed Stockton Rush and Rossi as well ..

   • I appreciate your position: trusting people who (seem to) offer transparency. In a way, it is exactly my position, too. Numerical transparency.

     As I’ve done here and on thousands of other comments at NextBigFuture, I have started with trying to determine some sort of paper-napkin mathematical transparency. Run the numbers, show where numerical physics agrees with the marketing hype (always good!), and where it disagrees. Follow the numbers (as per Brett Bellmore’s concerns) to work out the overall physics consequences of heat, mass, energy, magnetic field maintenance, and The Projections. Like going to Mars in 30 days. Like 1,000 kg spacecraft. Like (you choose) 2 megawatts or 200 megawatts of fusion enhanced ion energy. Those things.

     Believe it of not, using paper napkin math alone, with relative ease, I confirmed SpaceX’s projections well before the first rocket launch. I estimated and was pleased to confirm the amount of reserve fuel needed to soft-land the spent boosters. No, not exactly, but to within 25%, which is pretty good for napkin math.

     And I’ve done just such napkin math to call into question the gleeful marketing projections of the ‘flying car’ wannabes, the Rossi free energy claims, any and every magical thinking ‘tech’ announcement when encountered.

     Don’t get me wrong: I’m very, Very, VERY happy shaking hands with, and investing in those emerging technologies that actually pass the napkin math test before launch. But … maybe its becoming a lost Art, but ‘napkin math’ is how we got men to the Moon. A lot harder than ‘napkin math’ to prove it, to prove the power requirements, the materials strength and durability requirements. Actual woo-hoo computers ( a big thing in the 1960s ), with 11 decimals of precision. And remarkably useful math estimators called ‘slide rules’ for everything between.

     I believe this right now is a Pulsar Fusion paper tiger, backed by some small-scale real-world experiments … essentially confirming much of what was ‘discovered’ back in the VASIMR days, the 1970s and 1980s. As yet, not a single laboratory, anywhere, has demonstrated a thrust-producing nuclear fusion enriched rocket engine, at ANY scale, from the size of a ballpoint pen to a sub-kiloton monster. Nuthin’. Let’s just say, that I’ll be much, much more inclined to believe the marketing when the very basis Science itself begins to be proven.

     ⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
     ⋅-=≡ GoatGuy ✓ ≡=-⋅

3. I can’t do it, lads. Bolstering or ‘debating’ this is little like 17th century Jesuits wrangling over the number of angels that fit on the head of a pin. My disbelief meter is pegged and smoke is coming from its coils.

   ONE — 200,000,000 Watts in a 1,000 kg all-in weight probe

   Remember those ridiculously bright orange-white ‘sodium discharge bulbs’ that used to dot our highways, grocery megastore and used car lots? To work, they ionized a plasma of mercury and sodium metals to 5,000 °K or so, and SOMEHOW keep it contained (for years!) in the glass bulb. Without melting down, or exploding. Hardly ever.

   Being young and quizzical, I was struck by how fragile they looked. The secret, I later learned, was fuzed quartz. The sodium-mercury plasma bulb IN THE CENTER was made from ultra-high purity fuzed quartz, a material with enough heat resistance to contain the gasses while itself running up to over 1,500 °K.

   The ‘thermal problem’ even for the bulb-inside-the-bulb was a radiative one. To ‘beautify’ the color toward white, the outer bulb is coated with a UV fluorescent phosphor. Whitens the color substantially whilst increasing lumens per watt. Win-win.

   The point being though: temperatures high enough to melt almost all transparent materials, contained in a little bulb the size of a breakfast sausage. Quartz. Tungsten wires. 1,000 W in it. Plasma, no magnets.

   Pushing this up in scale to 200,000,000 W to me is mind boggling. At the very least, the staggering amount of power would need to be ‘bottled’ in something capable of dealing with the heat-per-area dissipation problem. Even if nearly all quartz (allowing for 1000 °K or higher operation), with an power-per-area density on the same level as the HPS light bulb, we’re still talking at least 500× the sausage dimensions.

   500 × 0.1 m = 50 m long.
   500 × 0.02 m = 10 m diameter.

   Volumetrically, that’s 50 m × 10 m • π (πD) × 0.003 m (thick) = 4.7 m³ of containment vessel. Which does NOT have a mass of a few hundred kg. Quartz has a ρ of 2,650 kg/m³ so that’d be 12,600 kg.

   BUT BUT BUT “you don’t need to contain it in space, right?”

   Oh, sure. Magnetic magic bottles. Big honking magnet coils powered by Holy Water, held apart from each other by magic wands. NOPE. My Disbelief Meter is pegging.

   We’re back to the basic 18th century physics issues again: mass, volume, mass, area, dissipation, heat, systems, complexity, mass, mass, mass and mass.

   See, I didn’t get to point number TWO.

   I haven’t even touched on

   (2) internal energy sources
   (3) thermal self-destruction mitigation systems
   (4) electronics overhead
   (5) science payload
   (6) reaction/fusion gas storage bottles
   (7) superconducting cryogenics cooling/retention
   (8) sputtering losses

   It really looks like a ‘paper tiger’ at this point. With CGI. Lots of yummy sweet CGI.

   ⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
   ⋅-=≡ GoatGuy ✓ ≡=-⋅

   • “ONE — 200,000,000 Watts in a 1,000 kg all-in weight probe”

     All of the material put out by Pulsar Fusion says 2,000,000 watts not 200,000,000 watts. I’m not saying it will work. I’m only pointing out the power claims by Pulsar Fusion are two orders of magnitude lower.

   • The gas temperature at the “throat” of a raptor engine is 3600K, much hotter than melting temps of anything its made of. Rockets, unlike sodium lamps, work some kind of magic involving an insulating layer of cooler gas (900k) in immediate contact with engine parts, in fact the whole art of rockets of all sorts is keeping them from melting even tho any exhaust worth exhausting (the thrusty fraction) is hot enough to melt them. Mystery to me. Felix on wai had a wonderful video titled “why dont rockets melt”, wish I understood it better but they observably dont melt and are not made from brittle ceramics.

4. I was talking to them a few weeks ago about it. They’re concentrating primarily on traditional in-space thrust and effectively just using this as a marketing tool to get their name out there until the tech matures.

   • That makes perfect sense. However, it does them no good in making such outrageous predictions and timeline

5. ‘Working Components’.. now that’s funny.

   Their video was simply pathetic. Perhaps OceanGate investors can send them some money.

6. “They just create the plasma and then the plasma generates the thrust on its own because it’s both ionized and high velocity and easily controlled by electromagnets. ”

   But that’s just VASIMR. Really, that’s all it is. Without fusion generating a lot of energy, ideally reaching engineering breakeven so that you don’t need a massive secondary power source, it’s just VASIMR.

   Agreed, it might be worth demonstrating that much works, while trying to get the fusion reaction going. But without a lot of fusion going on, it’s just VASIMR.

   And, again, I have to ask: Where are the radiators? Once they get it fusing, they’re going to have huge amounts of waste heat to dispose of, and it won’t all be going out the end.

   • I don´t understand the VASIMR comments.

     VASIMR works by ionizing an inert gas with radio waves and then accelerating it with magnets.

     Heating gas and accelerating it is the basic propulsion method of even a Saturn V.

     Thus you need 200 MW of power to ionize the gas then accelerate it to the high speeds at enough quantity to reach Mars in “30 days”.

     200 MW. With ultra light source. You can´t do it even with fusion. Maybe a Polywell Fusion reactor would do it with mass requirements.

     But anything that can do it with 200 MW, can do it better without all the losses of conversion.

     Pulsar plans to do it generating much less power.

     That happenes because you avoid conversions. You don´t ionize gas with radio waves. You don´t accelerate it with magnets.

     You fuse and then DIRECT the exhaust.

     That also means that if you can get 200 MW of fusion like the VASIMR requirements to reach Mars in 30 days, you can do much better than VASIMR

     • With no fusion it IS VASIMR, precisely. The more fusion they can achieve, the less like VASIMR it becomes, the more thrust per watt input they will get, because some of the energy in the exhaust is generated internally.

       So, I agree that even short of engineering breakeven, it would be substantially better than VASIMR if they’re fusing atoms. But the real payoff is if they can achieve engineering breakeven, and avoid having a secondary power supply.

       A secondary issue is that they plan on using a De-He3 reaction. He3 is extremely rare and expensive, world production annually is in the tens of kilograms. Their proposed mission to Pluto would wipe out the world supply. I assume they want to use it so they don’t have to deal with as many neutrons, but that’s going to be a real problem.

       • We agree. Pretty much ‘as always’. Thanks again!

       • world production is tens of kilograms even without any facilities dedicated to producing it. Li6 + N->H3+H4 can be used to make as much tritium as desired, in well-understood fission reactors, in a proven process long used to produce tritium for nuclear weapon boosting. 5% of that tritium would decay to He3 all by itself every year. Many reactors might be required but they would be much much cheaper and simpler than any D-D fusion reactor could ever be.

     • Fusion doesn’t happen all on its own You still have to heat up the atoms the exact same thing that you’re doing with a iron thruster. To say that these jokers intend to get the same thrust out of two megawatts instead of 200 megawatts means that they’re expecting to get huge fusion yields. Otherwise the math simply doesn’t work out. And obviously no one has gotten a huge fusion meals in the many decades of research on the subject. This is 110% vaporware.

       • The 2MW does not contribute to thrust. Those particles are not electrostatically accellerated, quite the opposite; electricity is generated by inductively SUBTRACTING a tiny fraction of the velocity from the charged exhaust. Its a byproduct. That electricity is just to run their equipment, lights, hairdryers, electric shavers, etc.

   • Speaking of radiators, Pulsar plans to get to Mars in 30 days with 2 MW of Power.

     VASIMR would need 200 MW.

     I guess the radiator problem is 2 orders of magnitude greater for VASIMR.

     • Heat dissipation has been my question all along. I know some heat will go with the exhaust, but for the rest how large will the radiator fins have to be ?

     • IIRC, the 200 MW for VASIMR was for a manned mission and not a 1 metric ton space probe.

     • The 2MW does not contribute to thrust, in fact is generated by SUBTRACTING a tiny fraction of the velocity from the charged thrust particles by induction. Does not need any turbine. its a byproduct. That electricity is just to run their equipment, lights, hairdryers, electric shavers, etc.

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