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Everything posted by Rakaydos

  1. "Enviromental racisim" = minorities are forced to live (via economic pressure, redlining, gentrification, whatever) in places most affected by climate change.
  2. Selected excerps: I'm not sure how you got "Solar is unviable" from this article.
  3. A single reactor is a single point of failure- sabotage, incompetency, enemy actors, political winds, anything that takes it out, takes it ALL out. this also applied to the distribution network to get the power where it needs to go, which isnt 100% efficent either. I dont know the first thing about what the actual numbers are, but at some point, distribution losses and grid failures have to be a larger concern than the "bulk discount" of a larger reactor. A bigger reactor also takes longer to design, build and bring online. That's another advantage to small modular reactors.
  4. Kilopower is a small reactor NASA designed for use on spacecraft... BEFORE Starship was on the horizon to make cheap lift a reality. It's less efficient that Megapower, (Which fits in a shipping container) which is less efficient than utility-scale nuclear, but modular nuclear has the benefits of eventually reaching economies of scale.
  5. There was a brief period when South Africa was looking like it was going to be a worldwide leader in advanced reactor design, back when Advanced meant pebble bed designs. But their teams ran into problems, I dont remember if they were technical or political, and they lost their lead. Also relevant: Megapower. NASA's Kilopower's bigger, earth bound (for now) brother. https://www.lanl.gov/discover/publications/1663/2019-february/_assets/docs/1663-33-Megapower.pdf
  6. Or, you know, lean into scifi even harder, and have some kind of unobtanium that is even more powerful, and cant be released in smaller amounts. Hyperspacial core tap to a higher energy dimension, which can only be opened for a few fractions of a second but releases enough energy to require a shock absorption plate.
  7. Orion was an "elegant in it's simplicity" workaround to the problems of making a nuclear engine. "Open cycle" engines, using your depleted power source as reaction mass, are vastly more effective than "closed cycle" ones, like NERV (a reactor heats propellant intead of burning it), the electric-pump rutherford (which only uses the batteries as a "preburner", and still has to dump batteries on the way up), and Ion engines (which use electricity to propell ions at frankly absurd velocities to get efficency, but not much actual thrust) Chemical rockets are almost all open cycle, burning the propellant in a chamber and letting a jet of the combustion product escape to produce thrust. You cant detonate a nuclear bomb inside a combustion chamber, but Orion showed that you can afford to waste a lot of the potential nuclear blast, if you can run open cycle, even without the chamber to direct the blast into a single jet. (and there was some optimization, that basically turned the bomb into two jets, so they managed to get almost 50% efficency out of it) But the better open-cycle nuclear engine design is the NSWR, which achieves criticallity in the propellant, AT the throat, so the blast happens in the nozzle where it can be directed. Both NSWR and Orion have the problem of spewing radioactive waste over your launchpad and the entire launch track, of course. That's the core problem with open cycle nuclear engines. Noone cares when a hydrogen/oxygen rocket spews H2O gas over the launch track, although some more exotic propellants also have concerns. But none of those concerns match that of nuclear waste.
  8. Modern reactor design loves to play with thermal expansion as an emergency control- because nuclear material has to be densely packed to generate a self sustaining reaction, which heats up the material, which lowers the density of the material. So it's possible to design a reactor that's just barely critical, as long as the coolant loop is functional at removing heat from the reactor- while at the same time making super-criticality a physical impossibility, as the reactor stops working well before the temperatures get high enough to be a problem for containment.
  9. Sounds like a problem with the soyuz, then.
  10. Lets face it, SpaceX's main selling point is "what have they done this week?" and they have very few dry spells. But this was supposed to be New Shepards time to shine... and Bezos made it about him, instead of about the flight.
  11. And yet, it's still cheap to put solar panels on roofs, over parking lots, and wherever they fit.
  12. That's the lie that the oil producers (including russia) have sold us, yes...
  13. I'm sure you love thanksgiving dinner, too, but eat like that every day and you arnt going to last a year. According to studies, plant growth rate is limited by available sunlight- while there is some minor benifit to a higher CO2, they arnt going to consume more with the same sunlight. "Sweater on your crops"- it's called a greenhouse, by the way. Cheapest source of power: Solar and Wind (https://en.wikipedia.org/wiki/Cost_of_electricity_by_source)
  14. There's hard limits there. Heat stroke is becoming an increasingly common problem in the warmer regions of the world. It's not cold that's the problem, it's UNEXPECTED cold. If you know it's coming, you just wear a sweater.
  15. Russia tells its space reporters to stop reporting on the space program | Ars Technica
  16. In case anyone remotely considers the above a serious suggestion- no. The long-chain hydrocarbons you're displacing contains far more carbon than the CO2 you are filling the same volume with, meaning that it's better to leave all the oil (and coal) in the ground than dig it up only to rebury it. We've already done enough damage, reversing millions of years of natural sequestration in only 200 years.
  17. In order for there to be transportation, there has to be a destination worth transporting to. Without the ISS, Commercial crew would never have happened. A SpaceX mars base/colony "beachhead" is a precondition for interplanetary science expeditions. There's no reason for Stanford to do LEO science and Lunar science is the domain of "the Goverment". But in the not so distant future, a non-govermental base on mars that offers base-camp amenities for expeditions into the martian wilderness is something that might attract institution-funded geological lewis-and-clark missions, funding the expansion of the base.
  18. The "committee" in question is the first crew. You want a better name, buy a new-build Dragon capsule flight and name it yourself.
  19. Like a microphone in front of it's speaker, this is not a good feedback loop.
  20. The flaps are actually about balancing during hypersonic entry, with different payloads. An empty tanker might enter with the nose flaps all the way retracted, while a crewed ship entering with heavy nose windows might have the flaps fully extended, to get the same entry profile.
  21. Note that your typical ICE car's gas tank contains the chemical energy of about 40 kilograms of TNT, and people are allowed to just fill them up at the pump, whenever. Even fill spare gascans.
  22. LM has in the past floated the proposal for a lander that was "comically large"... though less so that Starship. Launch it to orbit, utilize a dreaded D-word to get it to the moon, and reuse it for lighter lunar missions than Starship supports.
  23. While true, the military (and astronauts were very military, in the apollo days) is very good at glossing over the "suck" inherent in military duties. Apollo sanitation would just be an extension of that. The fact that Dragon is an improvement over apollo in that regard doesnt mean it isnt a step down from an Airstream camper.
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