sevenperforce Posted March 20 Share Posted March 20 28 minutes ago, Nuke said: early fusion drives wont be break even, they dont really have to be self sustaining. it will be nice to eventually tap them for electrical power, say for life support. that wont be until were at second or 3rd gen fusion power. but for now you just want fast charged particles. thus it has the same problem as any other electric thruster. its going to require some wattage. wheres do you get the power? we presently can get a few hundred kw using a really heavy bit of kit that doesn't work too far from the sun (the solar array on the iss). or we got rtgs which last decades on the order of half a kw and decreasing with age. The ever-useful Project Rho has a whole page dedicated to realistic fusion designs. The Firefly Starship is a particularly nice design. It's a true interstellar cruise spacecraft powered by Z-Pinch D-D fusion. Z-Pinch fusion has the advantage of being useful in the near-term. We should be able to do it with only a little more theoretical work, really. You don't have to have a self-sustaining fusion reaction since you are doing it in pulses. Quote Link to comment Share on other sites More sharing options...
Exoscientist Posted March 20 Share Posted March 20 1 hour ago, tater said: PS—taking the SpaceX thread towards fusion seems like pages and pages of off topic, better to make a thread for that, IMO. Probably right. I started a new thread. Bob Clark Quote Link to comment Share on other sites More sharing options...
tater Posted March 20 Share Posted March 20 1 minute ago, Exoscientist said: Probably right. I started a new thread. I think a norm around the ancient USENET practice of "Ob" (obligatory) content related to the subject at hand would go a long way. If a subject is tangential—like fusion—then either a direct connection to SpaceX... "Here's an image of a delivery to Roberts Road in FL of equipment from Fusion Corp!" or at least some legit SpaceX content/update within the post. Quote Link to comment Share on other sites More sharing options...
tater Posted March 20 Share Posted March 20 Quote Link to comment Share on other sites More sharing options...
tater Posted March 21 Share Posted March 21 Quote Link to comment Share on other sites More sharing options...
Nuke Posted March 21 Share Posted March 21 (edited) 17 hours ago, sevenperforce said: The ever-useful Project Rho has a whole page dedicated to realistic fusion designs. The Firefly Starship is a particularly nice design. It's a true interstellar cruise spacecraft powered by Z-Pinch D-D fusion. Z-Pinch fusion has the advantage of being useful in the near-term. We should be able to do it with only a little more theoretical work, really. You don't have to have a self-sustaining fusion reaction since you are doing it in pulses. i actually believe that fusion drives are closer than fusion power. but since its not break even you need an energy supply, eg solar, rtg, or reactor. same problem most plasma thrusters have. there are so many that are stuck on the drawing board or in a trl rut because testing in space is simply not possible (the space station power grid may allow for some thruster testing, that was the plan for vasimir, but as far as i know that is not something that has been done before, since the grid is mission critical, eg life support). we need better space power. Edited March 21 by Nuke Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted March 21 Share Posted March 21 17 hours ago, sevenperforce said: We should be able to do it with only a little more theoretical work, really. I've been hearing that about fusion power for the past 45 years. Quote Link to comment Share on other sites More sharing options...
Nuke Posted March 21 Share Posted March 21 16 hours ago, tater said: I think a norm around the ancient USENET practice of "Ob" (obligatory) content related to the subject at hand would go a long way. If a subject is tangential—like fusion—then either a direct connection to SpaceX... "Here's an image of a delivery to Roberts Road in FL of equipment from Fusion Corp!" or at least some legit SpaceX content/update within the post. weeeeeeeeeeeee! i doubt she was the only one that wanted to test the slide, there was probibly a line behind her. Quote Link to comment Share on other sites More sharing options...
Meecrob Posted March 21 Share Posted March 21 (edited) On 3/21/2024 at 3:35 AM, mikegarrison said: I've been hearing that about fusion power for the past 45 years. The difference between now and 45 years ago is that 45 years ago it would be nice to have fusion, but we had no reason to invest in it aside from research. Also, 45 years ago, we still had leaded gas, CFC's, etc. because we didn't understand (or chose not to understand) our impact on the planet. Now the Earth is literally on [Bill Nye] fire. Today, we NEED to develop fusion. I live in Toronto and we haven't had snow accumulation in the winter for half a decade. It melts after a week. Only a decade or two ago there was snow from January til mid March. To look at it a different way, replace "fusion" with "radar." From Wiki entry on Radar: "As early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects." However it wasn't until 1940 that the Radar was developed, obviously for the war. As soon as people realized radar might help save lives in air raids, they fast-tracked its development. Having said that, I am not accounting for unknown unknowns we might run into. I am more going from the point of view that a bunch of people with serious zeros on the end of their bank accounts are seeing an investment opportunity in fusion. Fossil fuel is dying. Fusion is the next backbone of our energy infrastructure. You better believe, for example, about half of the Saudi royal money is going into fusion R&D because Saudi Arabia is dead in the water when we stop buying oil in a decade. Edited March 24 by Meecrob Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted March 21 Share Posted March 21 11 hours ago, mikegarrison said: I've been hearing that about fusion power for the past 45 years. People say that (incorrectly) about sustainable fusion power, sure, but this is about an unsustainable pulsed Z-Pinch fusion propulsion. That's a much easier problem. If we had the political will to build it, we could do it without any major issues or new physics. Quote Link to comment Share on other sites More sharing options...
Vanamonde Posted March 21 Share Posted March 21 Until SpaceX actually starts working on fusion, please stick to the current topic. Which is SpaceX. Quote Link to comment Share on other sites More sharing options...
Spaceception Posted March 21 Share Posted March 21 About a third of Falcon 9 launches this year have been RTLS on ground pads, not bad. Quote Link to comment Share on other sites More sharing options...
JoeSchmuckatelli Posted March 21 Share Posted March 21 5 hours ago, Meecrob said: it wasn't until 1940 that the Radar was developed, obviously for the war Side note: radar was initially developed for weather and adapted to the war effort. Quote Link to comment Share on other sites More sharing options...
tater Posted March 22 Share Posted March 22 Quote Link to comment Share on other sites More sharing options...
tater Posted March 22 Share Posted March 22 Quote Link to comment Share on other sites More sharing options...
RCgothic Posted March 22 Share Posted March 22 IFT-1 pad destruction was likely as a result of a steam explosion from vaporised groundwater boiled by exhaust gas penetrating the cracked slab, argues a new paper: https://arxiv.org/abs/2403.10788 Quote Link to comment Share on other sites More sharing options...
tater Posted March 22 Share Posted March 22 Quote Link to comment Share on other sites More sharing options...
Spaceception Posted March 22 Share Posted March 22 (edited) Barely a week since the 3rd flight. It took about a month after IFT-2 to get the ship and booster to the pad ahead of static fires. When should we see the Booster on the move? Edited March 22 by Spaceception Quote Link to comment Share on other sites More sharing options...
RCgothic Posted March 22 Share Posted March 22 It took over 3 years for Falcon 9 to get flight cadence to under 3 months from the first flight. Starship not doing badly. Quote Link to comment Share on other sites More sharing options...
tater Posted March 23 Share Posted March 23 Quote Link to comment Share on other sites More sharing options...
tater Posted March 23 Share Posted March 23 Quote Link to comment Share on other sites More sharing options...
Spaceception Posted March 23 Share Posted March 23 I wonder how close they'll look to the IVA suits or promo shots. Quote Link to comment Share on other sites More sharing options...
Vanamonde Posted March 23 Share Posted March 23 Once again, please stick to the topic of SpaceX. Some comments removed. Quote Link to comment Share on other sites More sharing options...
tater Posted March 24 Share Posted March 24 Starlink launch at 11:09 eastern tonight Quote Link to comment Share on other sites More sharing options...
tater Posted March 24 Share Posted March 24 Quote Link to comment Share on other sites More sharing options...
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