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SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

arstechnica.com

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Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#281

Post by abledon »

patagurbon wrote: post #265
abledon wrote: post #136

Earlier quoted context omitted.

> because real problems are always more complicated than simple, inspirational ideas Colonizing another planet 'is' a real problem? Also, if we can 'just fix Earth' tell us how we convince all nations to come together and sing Kumbaya, put aside our resource differences and disarm all nuclear missiles (I'm looking at you North Korea)

North Korea is nowhere close to the major issue there.

ya, def not as big as climate change etc.. i just finished lex fridman podcast on north korea so it was on my mind

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#282

Post by onedognight »

908B64B197 wrote: post #31
milansuk wrote: post #14

In 2019, Elon tweeted[0] that the price of one Raptor engine is under $1M with the goal going under 250K for the next version. Any recent info where there are now? I'm still surprised they moved to this orbital fly so quickly without doing more tests. Going from 3 engines to almost 30 is crazy. Also, If I understand it right, both booster and starship will end up in the ocean. I hope they will be able to reuse at lea…

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”.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#283

Post by supperburg »

kristofferR wrote: post #257
matmatmatmat wrote: post #165

Earlier quoted context omitted.

> Go ahead and start "fixing earth" then, you're free to do so if you think it is "sexy". I don't think it's sexy, at all. It's hard work, but it's also necessary. > "colony run by a dictator" A space colony is a pretty harsh environment. I'd be that it'll tend toward harsh, centralized leadership sooner rather than later, but, you know, maybe I'm wrong on that. In my defense, the things that make democracy possible…

The "fix the Earth before archiving your dreams" fallacy would be way more convincing if Elon wasn't also behind Tesla.

And he also donated a hundred million dollars, literally a hundred million, to solving global warming. So the detractors don’t have a leg to stand on.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#284

Post by perl4ever »

dchichkov wrote: post #276
allenrb wrote: post #232

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.

>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 space, but completely unable to support themselves against 1G and so they can't lift off from the ground?

I feel like I've read something that said fusion power would fall in the same category.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#285

Post by [deleted] »

allenrb wrote: post #232

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.

[deleted]

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#286

Post by richk449 »

systemvoltage wrote: post #272
richk449 wrote: post #267

Earlier quoted context omitted.

I just skimmed through that document. Based on your description I was expecting a polemic. But actually about 90% of what they recommend looks like really good ways to improve math instruction. The big problem to me is that teaching math is hard, and teaching math well, as recommended in that booklet, is really hard. You can write all the pamphlets you want, but in the end the answer will be about the same - get real…

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. After having read the actual document, why would you think reading that letter would change my mind?

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#287

Post by fastball »

lucideer wrote: post #35
mulmen wrote: post #26

Earlier quoted context omitted.

This whole "whatever I don't like and/or understand isn't worth doing" philosophy is just not interesting. Humanity is not a hivemind. We can do more than one thing. History has countless examples of innovation in one area leading to breakthroughs in another. Just make your own contribution to humanity where you can, we will be fine.

That's true most of the time. Where it falls down is in cases where it's not "we". There's plenty of orgs doing worthwhile and important space exploration. There's a bunch of individuals destroying this planet who want to go to space and are selling a nice colonists fantasy to get backing. You're right that it's not either or: let's continue supporting viable space efforts. But let's not be naive about it.

Your comment sounds like you should be supporting SpaceX. SpaceX is one of the only orgs that has re-used orbital class rockets for useful payloads.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#288

Post by HALtheWise »

milansuk wrote: post #79
gridspy wrote: post #56

Earlier quoted context omitted.

The test flight trajectories are posted with the FAA and covered in numerous places, for instance Article: https://spaceflightnow.com/2021/05/13/spacex-outlines-plans-... Video (Marcus House): https://youtu.be/9-9k513UIVw?t=298 Basically both vechicles (the massive booster and the starship itself (2nd stage) are going to "land" on the water, which means a hover and then sinking into the water. Booster - Boost and sep…

Yep, this is what I meant, thanks for the sources. Although, I'm not sure about that "then sinking into the water" part. There are big LO2 and methane tanks and If they are empty enough and closed, both Starship and Booster shouldn't sink. I guest, we'll see it soon.

It's generally considered unlikely that the skyscraper-sizes rocket can fall over in the water and remain intact enough to float, although it did happen once to Falcon 9, so it's not impossible.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#289

Post by spfzero »

allenrb wrote: post #232

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.

Look at the numbers. SpaceX is doing it’s thing for a few billion a year. That’s chump change compared to the money being spent on, let’s say professional basketball. Not picking on basketball it’s my favorite spectator sport. But saying, if you want to find something less worthy than “improving the earth”, you have about a hundred better targets than space exploration.

Re: SpaceX installed 29 Raptor engines on a Super Heavy rocket last night

#290

Post by [deleted] »

sandworm101 wrote: post #254
dnautics wrote: post #247

Earlier quoted context omitted.

> 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…

[deleted]
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