701–710 of 1001 posts
Earlier quoted context omitted.
I still don’t understand why that post was flagged so quickly.
> SpaceX's Texas Rocket Is Going to Cause a Lot More Damage Than Anyone Thinks It might be the over-the-top title didn't do it any favors. It's in a gray zone between truth and click bait.
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That's an interesting point about the flight plan - if the intention of the flight was to test the vehicle at max Q, then the rest of the plan is almost a contingency. SpaceX: We expect the vehicle to reach 40km at which point it will probably blow up. FAA: Ok but what if it doesn't blow up? SpaceX: Well I suppose we could separate the stages. FAA: And then what happens? SpaceX: Well I suppose we could try to land th…
>> the intention of the flight was to test the vehicle at max Q, then the rest of the plan is almost a contingency. We don't know what the intention or internal expectation was. What we have are public statements, which are generally more conservative in order that every success be an amazing surprise, every failure an expected event. What SpaceX was internally hoping for, what they were aiming for, and the details o…
Of course there are plenty of systems after maxq they want to test, but not to sound like a software project manager, but "is the juice worth the squeeze?" Everything past maxq may not happen if the rocket goes RUD before or at that point, so how many points do you really want to be putting into stage separation, boostback, reentry, when those engineers could be triple checking Stage 0, fueling, start sequence, and liftoff?
Was it supposed to tumble and explode? Of course not. How many weeks of delay of booster launch is "don't tumble during stage separation" worth? SpaceX says on the order of zero, save it for the next unit in the heckin rocket assembly line (that is wild to say out loud but that's what it is).
People want to see 100% success in all things. But that isn't very economical. Compare the SLS to Starship. SLS has had a 100% success rate. One launch, one success. But it costs $2B per launch (and climbing) and has taken 12 years to get here. Plus, it's stealing pieces of the Space Shuttle, which was developed in the 70s over a long period of time. Starship will launch a half a dozen "failures" before they achieve…
>> People want to see 100% success in all things. But that isn't very economical. That sounds logical, but isn't really a thing in aerospace/space. Complicated high-energy systems have thousands of failure points. So to have any chance of success each failure point needs to be engineered below, by way of example, a 0.0001% chance of failure. That costs lots of money. But say one decides to accept more risk for less c…
Our ex ante ability to estimate these probabilities is lacking. Especially when they’re coupled. And redundancy, instead of tighter tolerances, is often cheaper than the classic approach. These are proven lessons from SpaceX.
People want to see 100% success in all things. But that isn't very economical. Compare the SLS to Starship. SLS has had a 100% success rate. One launch, one success. But it costs $2B per launch (and climbing) and has taken 12 years to get here. Plus, it's stealing pieces of the Space Shuttle, which was developed in the 70s over a long period of time. Starship will launch a half a dozen "failures" before they achieve…
Daily Mail (UK) and NY Post (US) are quoting the cost of this launch as $3B
> Musk has said the entire program will cost anywhere from $3 billion to $10 billion.
These can't both be true.
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The Soviet N1 moon rocket, which SpaceX shares a bit of design (30+ engines for example) failed 4 times before being scrapped. The Soviets had the 'launch often, fail fast, learn faster' view that SpaceX employs today. However, nobody viewed the N1 launches outside the Soviet Union as successes. I'm glad to see that 'fail fast, learn faster' is finally part of American aerospace engineering.
Very different situations. N1 was a technical blunder on many levels (and it wasn't a moon rocket - it was a hastily repurposed LEO launcher intended for in-orbit assembly, not optimal for the TLI). Instead of adopting the proven R-7 stacking scheme which was much easier to test piece by piece, Korolyov opted to a novel design which was too wide (17m!!), and static fires required a humongous and prohibitively expensi…
Why? It had pretty advanced engines, conservative fuel choices, architecture optimized for low requirements at manufacturing. And it was originally planned for Mars missions, not LEO missions.
> Korolyov opted to a novel design which was too wide (17m!!)
Why too wide? Technical decisions were made with all degrees of justifications available at the time. That it's wider than anything else till today, including Starship, doesn't make it "too wide".
> Combine this with other technical mistakes (the shape led to the extra weight while the modularity wasn't required, too much drag, etc)
Extra weight in weight-carrying construction is compensated, at least to a degree, by lesser weight of spherical tanks. Modularity was present so even N-11 was considered - two upper stages of N-1. Too much drag - comparing to what?
N-1 was quite state of the art technically when it was created. I don't see how calling it a technical blunder can be justified.
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I agree with this assessment and probably the biggest problem in the test. After that, they still have a fair way to go on Raptor reliability; I was a bit disappointed with the number of engine outs: clearly the engines have not arrived. I think the big win of the day was the overall resilience of the vehicle. It seemed to handle (what looked to be) possibly explosive engine failures and kept going and stayed intact.…
> but having that gut feeling that maybe there's more to a situation than the numbers would have you believe is still something that humans can do better In my life experience so far, humans having gut feelings it 99% of the time complete nonsense. But people forget the 99 times and that one time their gut was right they tell that story forever about how smart they were.
Yes, computers are really good at making calculations, but we have to tell them which calculations to make, so there's still (will always be?) a weak link in the chain.
People want to see 100% success in all things. But that isn't very economical. Compare the SLS to Starship. SLS has had a 100% success rate. One launch, one success. But it costs $2B per launch (and climbing) and has taken 12 years to get here. Plus, it's stealing pieces of the Space Shuttle, which was developed in the 70s over a long period of time. Starship will launch a half a dozen "failures" before they achieve…
starship will always be a failure built on lies. just youtube 'starship debunked'.
I get that there are multiple endpoints being tested here and some of them may have been satisfied, but I feel like I'm living in a bizarro world on hacker news where people are arguing that multiple failed engines, a failed stage detachment and an exploding rocket worth millions of dollars and and carrying a large number of limited supply raptor engines is a "massive success". Can we just call it for what it is? Mix…
People want to see 100% success in all things. But that isn't very economical. Compare the SLS to Starship. SLS has had a 100% success rate. One launch, one success. But it costs $2B per launch (and climbing) and has taken 12 years to get here. Plus, it's stealing pieces of the Space Shuttle, which was developed in the 70s over a long period of time. Starship will launch a half a dozen "failures" before they achieve…
How much did starship cost?
If you hang the entire R&D plus materials cost for Starship on this one launch, it's a huge amount.
If you consider this as R&D that will be amortized over decades of launches, not that much.
It's the same math that gets you the military buying $5000 hammers: it all depends how you allocate fixed costs across units.
Earlier quoted context omitted.
I still don’t understand why that post was flagged so quickly.
> SpaceX's Texas Rocket Is Going to Cause a Lot More Damage Than Anyone Thinks It might be the over-the-top title didn't do it any favors. It's in a gray zone between truth and click bait.