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I don’t understand why these chemical rockets and another flight to the moon are needed. Isn’t it a dead end? And pointless carbon emissions on the way? Nucle
by startupsfail 3y ago
I don’t understand why these chemical rockets and another flight to the moon are needed. Isn’t it a dead end? And pointless carbon emissions on the way?
Nuclear fusion gives a path to clean energy and allows star-flight. Chemical rockets don’t.
- usrusr 3y agoIf we had fusion, methane rockets would be exactly what we'd want to build
- anon84873628 3y agoCarbon "sequestration" and space travel all in one!
- tekla 3y agoPlease inform the rest of us, the unwashed plebs, exactly what technology exists to get us off this rock to the moom that isnt chemistry based and can be used in the next 20 years
- verdverm 3y agoPerhaps a space elevator if we put in the effort
- startupsfail 3y agoWhat happened to ground based laser propulsion? Where you heat up the propellant with a ground based laser during takeoff and then use the same laser source to power your ship is space? I remember a few videos of launching small rockets with a ground based laser from some twenty years ago. Haven’t laser technology improved since?
- taylorportman 3y agoA plasma jet powered by fusion?
- ianburrell 3y agoNone of the proposed fusion reactors are suitable for getting off the planet. They will be too heavy. And won’t produce plasma jets. Fission reactors have the same problem. It is possible to use them in space but not to get into space.
- startupsfail 3y agoPFRC2? There’ve been some attempts to build an atomic aircraft, decades ago. Haven’t technology of compact reactors improved since?
- ianburrell 3y agoAll the recent work on compact reactors has been on modular ones that don’t care about weight. I think there have been studies about nuclear rockets but no active development programs. Fission rockets are useless for launching to space because the thrust is too low, or the weight is too high. They could be useful in space because their higher exhaust velocity. But high exhaust velocity means low thrust.
- wiml 3y agoDo we have any approaches to fusion that would be usable for launches? I mean, ones that we could possibly prototype within a decade, not just Project Rho links, much as I enjoy Project Rho.
- startupsfail 3y agoPFRC2? I think the whole fusion thing is like A.I. or electric vehicles. You simply need someone to really push it, and you can get there. Instead of having the status quo keepers running the things on fossil fuels and collecting guaranteed income to build even larger yachts.
- bryanlarsen 3y agoEstimated performance is 10 Newtons per megawatt. Useful to replace ion engines for interstellar spacecraft, but not useful to escape Earth's gravity well. cf Starship with about 75 million Newtons of thrust. https://en.m.wikipedia.org/wiki/Direct_Fusion_Drive https://en.m.wikipedia.org/wiki/Direct_Fusion_Drive
- startupsfail 3y agoIf you have a good, compact inexhaustible source of clean energy that gives you megawatts of it, you should be able to turn it into delta-V. You can use atmosphere as the propellant. And accelerate as much as you need at the upper levels of atmosphere. Potentially you can use aerodynamics (basically fly inverted) to get to even higher velocity than the orbital velocity. Then, you can stay there at the upper levels, as long as you need to, and charge your tanks (you can initially take off with an empty tank of propellant). Once this is done, you can adjust the angle of attack and ease of into the higher orbit, switching to space flight. It involves hypersonic flight, but there is nothing impossible here.