291–300 of 421 posts
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> SpaceX didn't invent rocket engines They kind of did invent full-flow engines though, which were an unattained holy grail of rocketry.
https://en.wikipedia.org/wiki/Integrated_Powerhead_Demonstra...
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I suggest to read the open letter (signed by more than 600 professors and professionals including 2 Nobel laureates) before you make conclusions: https://www.independent.org/news/article.asp?id=13658
The letter appears to be criticizing a different document: The California Mathematics Framework. That framework appears to be around a thousand pages, which I don't have time to read right now, unfortunately. It is strange that you think that letter would change my opinion though. It doesn't really contain any analysis or arguments. It just says that the changes are bad, and here is a long list of people that agree.…
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Just ... No. Read the history. At least read Wikipedia. "Staged combustion (Замкнутая схема) was first proposed by Alexey Isaev in 1949. The first staged combustion engine was the S1.5400 (11D33) used in the Soviet planetary rocket, designed by Melnikov, a former assistant to Isaev.[1] About the same time (1959), Nikolai Kuznetsov began work on the closed cycle engine NK-9 for Korolev's orbital ICBM, GR-1. Kuznetsov…
> The first flight test of a full-flow staged-combustion engine occurred on 25 July 2019 when SpaceX flew their Raptor methalox FFSC engine at their South Texas Launch Site.[8] (Yes, there are others listed, but SpaceX was first to actually fly something.)
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Using these resources to improve chemical flamethrowers is sub-optimal. A dead end. Nuclear fusion is a more likely answer to spaceflight and Earth's clean energy problem. It likely should be the priority.
>Nuclear fusion is a more likely answer to spaceflight and Earth's clean energy problem. Considering we don't even have fission rockets or airplanes in normal use, making a fusion powerplant that is light enough to get off the ground seems very far fetched. Even if we eventually use fusion for travel beyond earth orbit, I'd bet chemical rockets would still be in use. Don't we already have thrusters that are useful in…
Yes. For example ion thrusters have specific impulse that is like an order of magnitude or two (or three?) better than chemical rockets, but they can't lift anything out of the atmosphere.
> I feel like I've read something that said fusion power would fall in the same category.
Sorry I have no idea about that.
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This is such an annoying argument. The government gave $18B to the SLS and so far has vapor: https://en.wikipedia.org/wiki/Space_Launch_System The government spent $211B on the shuttle program and got 133 launches. SpaceX will probably surpass that number this year at a fraction of the cost. NASA's record on rockets since Apollo has been abysmal. I don't think government is necessarily bad (the Russians did a much be…
> Russians did a much better job in recent decades The multiple problems with Nauka suggest they've lost their edge and never learned the lessons from docking issues with Progress in the past.
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> SpaceX didn't invent rocket engines They kind of did invent full-flow engines though, which were an unattained holy grail of rocketry.
Just ... No. Read the history. At least read Wikipedia. "Staged combustion (Замкнутая схема) was first proposed by Alexey Isaev in 1949. The first staged combustion engine was the S1.5400 (11D33) used in the Soviet planetary rocket, designed by Melnikov, a former assistant to Isaev.[1] About the same time (1959), Nikolai Kuznetsov began work on the closed cycle engine NK-9 for Korolev's orbital ICBM, GR-1. Kuznetsov…
How so many educated, intelligent people seem to think that we (as a species, or even as Americans) are so resource-poor that “space exploration” and “improving the earth” yield an either/or decision absolutely mystifies me. You want to free up resources for either one? Start with global military spending and the financial sector. Both have their place and both have grown far beyond it.
Using these resources to improve chemical flamethrowers is sub-optimal. A dead end. Nuclear fusion is a more likely answer to spaceflight and Earth's clean energy problem. It likely should be the priority.
Fusion still shares the same fundumental problem that chemical rockets or even more advanced options like blackhole or antimatter drives face - the rocket equation. We need to use near term reusable launch vehicles like the Starship to help set up the required launch assist structures that would make genuine mass transit of people and cargo into orbit possible.
Things like skyhooks, lofstroom loops, and eventually orbital rings that would allow people to ride trains or cable cars from an earth city straight into orbit for the same price range as intercity travel today. Needless to say, that is not going to happen until there is enough of an industry up there to justify the large upfront costs of such megaprojects (especially the orbital ring) so the Starship is our best near term hope of getting us up to that point.
Note that none of these projects require advanced materials or new technologies (as opposed to the space elevator that is likely to remain science fiction when it comes to dealing with a body with the gravity well of earth anyway), they're just massive engineering projects.
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Only in America things like this can happen. A whole industry bootstrapping itself to make semi-conductors doubling every 18 months, going from exotic, mission critical hardware to commodity; SpaceX is doing the same thing with flight hardware. Contrast that with previous generation engines (the RS-25 comes to mind) with a sticker price of 125 millions... per engine! [0] [0] https://spacenews.com/aerojet-rocketdyne-d…
SpaceX has quite a few engineers that learned the practical details of rocketry on the government’s dime. Be it at NASA or Boeing or an aerospace department at a university that gets government funding. I don’t mean to detract from SpaceX’s accomplishment, but they “bootstrapped” themselves the way a rich kid starts a company using the resources and connections put in place by his “family”.
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https://en.wikipedia.org/wiki/Integrated_Powerhead_Demonstra...
different fuels from the raptor, though, so it's not like spacex didn't have to figure a ton of stuff out anyways, and also it never flew.
That the IPD was hydrolox and didn't proceed to the point of a full engine, let alone a flight is besides the point.
What you said was: "They kind of did invent full-flow engines though", which is completely false.
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Using these resources to improve chemical flamethrowers is sub-optimal. A dead end. Nuclear fusion is a more likely answer to spaceflight and Earth's clean energy problem. It likely should be the priority.
>Nuclear fusion is a more likely answer to spaceflight and Earth's clean energy problem. Considering we don't even have fission rockets or airplanes in normal use, making a fusion powerplant that is light enough to get off the ground seems very far fetched. Even if we eventually use fusion for travel beyond earth orbit, I'd bet chemical rockets would still be in use. Don't we already have thrusters that are useful in…
As absurd as it sounds nuclear powered aircraft engines are a thing.[1] They have also been proposed for spacecraft, Scott Manley does a great video talking about nuclear rocket engines[2].