LOX is liquid oxygen, which is not a fuel, but an oxidizer. Starship is fueled by liquid methane. Methane can not be made from just water, you need a source of carbon. On Mars for example methane could be produced from CO2 in the atmosphere and water from ice.
ylph
joined 1 year ago
YouTube video ads can't be blocked with just DNS blocking unfortunately, they are served from the same hosts as YouTube videos.
I don't know much about the Hyperloop - I was never interested in it, and it never seemed like a real project, some kind of Musk BS probably, but I don't know enough to debate it. Full Autonomous driving is definitely also a very ambitious project. I do think it is in principle feasible, and has great potential, but also serious possible obstacles. I think it's worth pursuing to figure it out. I would say that selling it to the mass market is premature at this point, and has been overhyped by Musk a lot. Also don't know anything about the Human/Robot AI program, that also sounds like Musk BS, so I don't really follow it.
I do think Musk is a narcissist, I don't think he is an idiot. I don't think calling him a con-man is really justified. I also don't think he is a genius, more like someone with decent amount of technical competence who often unreasonably clings to slightly insane visions and an ability to assemble talented people and push them to try to execute on those visions and ideas, which sometimes leads to legitimate breakthroughs, for example in case of SpaceX.
I would never take Musk's predictions, economic or technological at face value, he is clearly always talking far ahead of anything currently happening, an his predictions are notoriously unreliable and wildly optimistic. I don't think that takes away much from the actual achievements of both Tesla and especially SpaceX however.
I also personally would never buy a Tesla, for a variety of reasons - I actually have a lot of disagreements with the Tesla philosophy, and will probably never own a self-driving car either, but whatever.
If a NASA program had as many failures as SpaceX has, it would be closed down.
94 successful Falcon 9 launches this year so far (0 failures) - 90% with reused boosters, with a single booster being flown for the 19th time yesterday - no launch system has ever come close to these kinds of numbers before.
If by "many failures" you are referring to Starship, those are literally test articles/pathfinders/prototypes tested to destruction. It's a different development approach than NASA's, so I am not sure how the comparison is applicable. It took many failed booster landings early in the Falcon program to perfect the droneship landing, and look where it is now.
Starship is a very ambitious program, really pushing the boundaries of our technological capability and challenging a lot of existing conventions. Even Elon admits success is far from certain, but declaring it doomed based on the test flight results so far is really premature.
Yup, Corsair replaced a pair of modules that were ~4 years old for me earlier this year, they even shipped the replacements first before I sent the bad module in - all at no cost in the end (only a deposit for shipping first, which was fully refunded once they received my old modules). I didn't even realize they had lifetime warranty at first, didn't think such things even exist anymore, so it was a really nice surprise.
I had years of infrequent random crashes that I finally tracked to a bad DRAM module - I was kicking myself for not running the full memtest earlier.
What's wrong with using a text editor to remove lines ? In vim for example :g/pattern/d or :g!/pattern/d with regular expressions is a powerful tool for removing lines in bulk if needed.
The first computer I used was a PDP-8 clone, which was a very primitive machine by today's standards - it only had 4k words of RAM (hand-made magnetic core memory !) - you could actually do simple programming tasks (such as short sequences of code to load software from paper tape) by entering machine code directly into memory by flipping mechanical switches on the front panel of the machine for individual bits (for data and memory addresses)
You could also write assembly code on paper, and then convert it into machine code by hand, and manually punch the resulting code sequence onto paper tape to then load into the machine (we had a manual paper punching device for this purpose)
Even with only 4k words of RAM, there were actually multiple assemblers and even compilers and interpreters available for the PDP-8 (FOCAL, FORTRAN, PASCAL, BASIC) - we only had a teletype interface (that printed output on paper), no monitor/terminal, so editing code on the machine itself was challenging, although there was a line editor which you could use, generally to enter programs you wrote on paper beforehand.
Writing assembly code is not actually the same as writing straight machine code - assemblers actually do provide a very useful layer of abstraction, such as function calls, symbolic addressing, variables, etc. - instead of having to always specify memory locations, you could use names to refer to jump points/loops, variables, functions, etc. - the assembler would then convert those into specific addresses as needed, so a small change of code or data structures wouldn't require huge manual process of recalculating all the memory locations as a result, it's all done automatically by the assembler.
So yeah, writing assembly code is still a lot easier than writing direct machine code - even when assembling by hand, you would generally start with assembly code, and just do the extra work that an assembler would do, but by hand.
The only fuel you can make from water is hydrogen. The RS-25 engines used on the SLS core stage and the Space Shuttle used liquid hydrogen, as did the J-2 engines on the second and third stage of the Saturn V (but not the first stage, which used RP-1 (kerosene) burning F-1 engine)
Starship's Raptor engines use liquid methane however. There are a bunch of tradeoffs between the different fuels, but generally liquid hydrogen is more difficult and expensive to deal with. With low cost reusability being one of the primary objectives of Starship, liquid methane was chosen as the best option. The fact that it can also be manufactured on Mars was also considered, since CO2 is abundant in Martian atmosphere.