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On the 'repeated failures' piece, that's somewhat new for aerospace. Traditionally, things would be over-engineered, and losing a test vessel would be considere
by cmoscoe 6y ago
On the 'repeated failures' piece, that's somewhat new for aerospace. Traditionally, things would be over-engineered, and losing a test vessel would be considered a bad thing. SpaceX seems very content to blow up a bunch of rockets on their way towards not blowing up rockets.
This seems to have caused at least part of their recent issues with the FAA, who seem to be less ok with explosions. It will be very interesting to see if this iterative approach leads to more reliable rockets down the line!
- bondolo 6y agoThe FAA seems to be concerned with exploded bits falling on innocent people. You are welcome to blow up your rockets all day long if you aren't putting other people at risk.
- sneak 6y agoThe SpaceX rockets don't fly anywhere near people. Nobody is underneath any part of their flight path or within any possible destruction radii.
- elmomle 6y agoPlenty of American rockets failed, especially early on! https://www.youtube.com/watch?v=13qeX98tAS8 https://www.youtube.com/watch?v=13qeX98tAS8
- DennisP 6y agoAnd SpaceX has blown up ten Falcons on landing attempts.
- CydeWeys 6y agoAfter accomplishing their primary mission, which is a key distinction. If you blow up on landing that just means you lose your reuse discount on a future flight.
- AstralStorm 6y agoThat's no good for Starship, which is meant to land with passengers and hardware on board.
- CydeWeys 6y agoYeah, which is why they're making Starship better than the Falcon 9 in being able to land safely even when things go wrong (i.e. Starship can throttle down enough to hover). They're still in the early prototyping stages. You can't judge potential long-term reliability based solely on what we've seen so far.
- Alupis 6y ago*While building the first space rockets in the world, literally making it up as they went. That's not quite the same situation SpaceX is in right now.
- DennisP 6y agoActually it is the same situation. The launch was fine. What blew it up is something nobody has attempted before.
- unanswered 6y agoIt's totally different because only the government is allowed second chances! Everyone else has to get it right the first time. Especially if they're competing with <insert defense/aerospace contractors here>!
- deleted 6y ago[deleted]
- HarryHirsch 6y agoNever attempted what? Relight an engine? Engines are routinely re-lit, especially on upper stages, yet Space-X gets it wrong with regularity. The Russians and Arianespace do it just fine.
- twicetwice 6y agoI'm sorry, what? SpaceX are the undisputed champions of re-lighting engines. They've landed orbital rockets 73+ times, each of which involves multiple engine re-lights while falling through the atmosphere. Let alone gets it wrong "with regularity" — the Falcon 9 Block 5 is a remarkably reliable rocket. Anyway, landing Starship involves a bunch of things never before attempted: landing a fully-reusable second stage, landing a vehicle of this size, relighting and running engines during the belly-flop-and-flip maneuver, and flying and relighting full-flow staged-combustion engines. Probably some other firsts too.
- minikites 6y agoWhy is SpaceX making the same mistakes 70 years later?
- naikrovek 6y agoI don't recall NASA ever doing a rocket landing so I'm not sure which mistakes you are seeing repeated.
- bacon_waffle 6y agoI was surprised to learn recently that NASA did do some rocket landings in the 90s: https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X
- naikrovek 6y agoOk, so which mistakes is SpaceX making that NASA also made?
- sudosysgen 6y agoNASA and the USSR did many powered rocket landings, actually. NASA even had a program for reusable first stages via powered landings that was scrapped because automatic guidance wasn't feasible yet.
- naikrovek 6y agoOk, so which mistakes is SpaceX making that NASA also made?
- sudosysgen 6y agoFailing to restart an engine in a retrograde trajectory. A difficult task that both the Soviets and NASA (and Arianespace and the Chinese) had issues with, but worked out. It's very difficult because of the turbulent airflow in an engine bell pointed against the airspeed vector. Despite this, many rocket engines can do it reliably.
- deleted 6y ago[deleted]
- HPsquared 6y agoThe early days of the Soviet space program were similar - fast construction and iterative improvements with each successive test.
- avmich 6y agoSoviet rocketry was developed in the artillery department. There iterations are normal. US rocketry was developed under Air Force - here more experienced pilots, lots of training...
- toss1 6y ago>> On the 'repeated failures' piece, that's somewhat new for aerospace Unless you go back to the early pre-Mercury program days of NASA - they had lots of failures, and that was just trying to go up without re-usability, not land and reuse. There's all kinds of fun failure reels (e.g., [1]) and lists (e.g., [2]) [1] https://www.youtube.com/watch?v=g79K-R7xTFo https://www.youtube.com/watch?v=g79K-R7xTFo [2] https://en.wikipedia.org/wiki/List_of_spaceflight-related_accidents_and_incidents https://en.wikipedia.org/wiki/List_of_spaceflight-related_ac...
- bryananderson 6y agoIt’s really a throwback to the old days of aerospace. From the 1930s to the early 1960s, the standard method was to iterate rapidly with relatively cheap hardware, to learn and fix problems as quickly as possible. The von Braun and Korolev teams operated this way, among others. They all blew up a ton of rockets. What changed was the necessity of completing Saturn V and landing on the Moon by the end of the 1960s. Apollo program head George Mueller recognized that, with the planned number of iterative tests, they were going to be too late. He made the gutsy decision to launch “all-up”: spend a ton of money up front to overengineer the crap out of the vehicle and cut out most of the iteration. It worked! But alas, the aerospace world overlearned the lesson and has been cargo-culting it ever since. Mueller’s decision was purely a matter of expediency to meet Kennedy’s goal and beat the Russians. It wasn’t a statement that this was the best way to do engineering, absent those constraints. To make matters worse, all-up only works under the funding conditions of Apollo: a massive spike in funding to cover the up-front cost. Without that spike, the costly development phase has to be stretched out, and the whole thing ends up taking longer than iteration. In other words, you can save time this way when money is absolutely no object, but otherwise you lose time. See Boeing’s SLS: basically 15 years of development and they just static-fired it for the first time. Launch is maybe a year away. We’ve all gotten used to the all-up style of development, and SpaceX’s rediscovery of rapid iteration makes it seem like a new and untested way of doing things. But I think the dominant narrative—that all-up is prudent and conservative while iterative is risky—is completely backward. All-up carries a massive amount of risk that fundamental design issues won’t become apparent until the tremendously costly development phase is done. Iteration allows assumptions to be tested and modified as quickly as possible. Most of SpaceX’s early ideas about reusability turned out to be wrong. If they had committed all the money and time to those early concepts before flight-testing, they would have never accomplished it. The early rocketry pioneers operated this way, and it’s why they accomplished the things they did. Maybe SpaceX will finally free the space industry from perpetually repeating what worked for Apollo, which after all operated under unique political conditions.
- bernulli 6y agoI’m not sure 3200 full scale tests of Saturn V’s F-1 engine, 2000 in an iterative trial-and-error scramble to suppress combustion instabilities is what I would call “overengineered to cut out iteration” during Apollo http://www.yang.gatech.edu/publications/Journal/JPP%20(1993,%20Oefelein).pdf http://www.yang.gatech.edu/publications/Journal/JPP%20(1993,...
- ekianjo 6y ago> that's somewhat new for aerospace Because NASA does not launch anything anymore. If they were doing hundreds of launches per year you can bet you'd see failures the whole time.
- MPSimmons 6y agoYou're basically watching the CI/CD workflow for the best aerospace organization in the world, live on YouTube.