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The problems with Starship make the Saturn V and STS programs even more impressive. However, I still don't get the rationale of building a rocket with such a la
by fsh 1y ago
The problems with Starship make the Saturn V and STS programs even more impressive. However, I still don't get the rationale of building a rocket with such a large payload. The rocket equation will always force you to build an absolute monster compared to a series of smaller rockets. Even worse if you have to haul up a massive orbiter each time. No wonder that small/medium sized rockets (Soyuz, Atlas, Ariane, Falcon 9,...) have always been the most successful.
- quotemstr 1y ago> STS programs The shuttle was a deathtrap. It had inadequate abort modes and a launch process that practically guaranteed minor (until it wasn't) damage to the heat shield during launch. Classic example of https://danluu.com/wat/ https://danluu.com/wat/ --- the normalization of deviance. STS crews were lucky that only two of the things got violenly disassembled.
- fsh 1y agoSure, the Saturn V and STS were much less safe than smaller rockets. Still, they blew up an awful lot less than other rockets of their size like N1 or Starship.
- nomel 1y ago> Still, they blew up an awful lot less than other rockets of their size like N1 or Starship. I think the only reasonable comparison would be after cost equivalency. The Starship has a long way to go, to catch up.
- jeroenhd 1y agoCost equivalency ignores the R&D and decades of scientific progress and advancements in tooling capability. The prices of materials have shifted, but designing and manufacturing a precise propulsion system with modern CAD and simulation tools is a lot cheaper than the hand work hundreds of people used to be doing to verify much simpler engine designs. Precision machining and tools to inspect metal fatigue and imperfections have also come a long way. Of course commercial rockets are always going to be as shoddy as they can get away with rather than as good as possible, but if it still takes SpaceX or Boeing as much money to build a rocket as it did back in the Saturn V days, they're doing something wrong.
- Aeolun 1y agoIf you use that as an argument any comparison becomes meaningless by default.
- b112 1y agoMany Saturns blew up during testing. Starship is still in testing. Your arguments are strange, a mirage concocted to fit a narrative of denigration and darkness. You mock with zeal, yet have no point to the mocking. Always with the mocking, you cause an ache which cannot be balmed. Cease, I pray you. Stop these machinations, this mad canter. Falcon was built the same way. It blew up many times too, explosions aplenty. Now it is the most successful lift on the planet.
- ubercore 1y agoWould love to read about Saturn V explosions during testing. Have a link?
- b112 1y agoI recall reading the engines blew up in testing, the rockets on the pad, on and on. And why wouldnt it? No one has ever built a plane, or even a car without breakage during testing. The very idea is absurd. There's a whole profession called "test pilot". I don't know why anyone would suggest otherwise. I'm sure there are links aplenty, but the absurd suggestion here would be building a rocket and having zero incidents of failure. That beyond weird. That's what needs a "do you have a link" question.
- rsynnott 1y ago> I recall reading the engines blew up in testing, the rockets on the pad, on and on. And why wouldnt it? You're recalling wrong, or you were reading nonsense. Lots of engines were destroyed in testing (particularly before computer modelling, this was basically how rocket engines were _developed_), but no, no Saturn V ever exploded on the pad. Prior to this incident, the most-impressive on-pad boom was one of the N1s. No fully assembled Saturn V ever failed, though a few of them had near-misses.
- b112 1y agoWell we're discussing testing only here, so are you sure none explpded on a test a pad? It's a weird debarc point to discuss non testing craft vs testing. And "fully assembled", when spacex is flying non-final builds on purpose, using a different test methodology.
- aredox 1y agoAlso, both Saturn V and the Space Shuttle were dual-purpose programs - they had military goals on top of the scientific ones.
- blkhawk 1y agoWell the military purpose was why the Shuttle was so crappy. The original design was smaller and meant to sit on top of its rocket. This would have probably prevented loss of crew in both of the instances where shuttle failed.
- panick21_ 1y agoEventually Starship will also be bid for military programs. And Saturn V never had a military mission, neither had Shuttle.
- TheOtherHobbes 1y agohttps://en.wikipedia.org/wiki/Category:Department_of_Defense_Space_Shuttle_missions https://en.wikipedia.org/wiki/Category:Department_of_Defense...
- m4rtink 1y agoShuttle regularly launched spy sats and was designed to grab an enemy one in a single orbit mission. Also Soviets believed it would nuke Moscow by sudden plane change via its wings & build their own version as a result. That sounds military enough for me.
- dotancohen 1y agoThe bombing of the Soviet Union was to happen via polar launch. The wings were there not for plane change, rather for cross range landing after the single orbit polar mission.
- m4rtink 1y agoInteresting - I was never sure about the exact mechanism m, just that the orbital speed & lift provided by wings were part of it. :)
- cma 1y ago> It had inadequate abort modes Does Starship have launch abort boosters? Seems infeasible with the amount of fuel and mass on it since it also serves as a second stage, but maybe they solved that somehow?
- MPSimmons 1y agoStarship doesn't currently have launch abort modes
- mjevans 1y agoNor does it have any crew / passenger cargo.
- cma 1y agoDearMoon was supposed to launch 2022, passenger space service between LA and Ridhya by 2028 (announced in 2018 and they said it was on track for 2028 still several years later). They said it would be around the price of business class air travel and be in full commercial operation by then. That might have been after they started adding "aspirationally" to most Musk company statements following some lawsuits.
- imtringued 1y agoI suggest you read up on the rocket equation again. There is a massive difference between payload mass fraction and payload. The latter scales linearly with respect to the total mass.
- fsh 1y agoThat's the problem. Building a heavier rocket is much harder than building a lighter one (see explosion above). So why not send a few lighter ones instead of a heavy one? This is what the launch market has concluded for a long time.
- danw1979 1y agoLet’s assume starship works out and they come up with a nifty wide-opening payload door solution, one of the advantages will be payload volume as well as mass - the JWST’s main mirror would have fit inside without being folded (although the heat shield would not have).
- SlightlyLeftPad 1y agoThis is a long but great video from Destin that goes over this in detail: https://www.youtube.com/watch?v=OoJsPvmFixU&pp=0gcJCdgAo7VqN5tD https://www.youtube.com/watch?v=OoJsPvmFixU&pp=0gcJCdgAo7VqN...
- JumpCrisscross 1y agoDestin’s arguments make sense if we want to redo Apollo. They break down if we’re trying to make repeated missions into deep space more economical.
- ThrowMeAway1618 1y ago>So why not send a few lighter ones instead of a heavy one? This is what the launch market has concluded for a long time. I want to do Apollo again.[0] [0] https://www.youtube.com/watch?v=A4J9uvhJQM0 https://www.youtube.com/watch?v=A4J9uvhJQM0
- 1y ago
- trhway 1y ago> However, I still don't get the rationale of building a rocket with such a large payload Operations cost. They are sublinear on payload/size. At least this is what Space X/Musk seem to go for.
- e_y_ 1y agohttps://en.wikipedia.org/wiki/Big_dumb_booster https://en.wikipedia.org/wiki/Big_dumb_booster There's also many advantages to being able to lift something large/heavy in one go, rather than smaller payloads that need to be unfolded (like JWST) or assembled in space, which can drastically increase the development costs.
- hliyan 1y agoEven more impressive to me is the fact that Saturn V did in a single launch with 1969 technology, what we're now proposing to do with 10-15 Starship launches (each as large as a Saturn V) and an additional SLS launch for Orion return capsule. What's more, the US had orbital launch expereince of just 3 years (Explorer 1 in 1958) when the Apollo program began, and 8 years later they were on the moon. Perhaps web development is not the only thing that is susceptible to bloat.
- trhway 1y ago>Saturn V did in a single launch with 1969 technology, for up to 0.8% US GDP per year. Today that would be $200B/year, pure spent. Where is Space X today is making, ie. it has a revenue, $15B/year. >Perhaps web development is not the only thing that is susceptible to bloat. similarly - web dev today can be done on $300 laptop by any schmuck. Even simple programming back then required a computer which cost a lot, and it was an almost academic activity.
- supermatt 1y agoSure, but spacex are building on the shoulders of what came before. Easy to save 200bn on research and development if someone else has already paid for it and shares the results for free.
- inglor_cz 1y agoThis is true, but also a bit trivial to observe. Even the Primitive Technology channel, which usually starts with mud and clay, builds on knowledge of other people. The value added is interesting. For example, both the Merlin and the Raptor family of engines. These are some fine engines, and they are remarkably cheap and reusable.
- supermatt 1y agooh sure, no doubt - and the universe before that, etc. but here the baseline set by the comment i responded to was "whatever nasa spent 200b on".
- panick21_ 1y agoFalcon 9 is by no means small or even medium. In the history of rockets its quite a large and powerful rocket. And so is Ariane 5. Not sure what you are referencing with Ariane, I guess Ariane 1-4 were small. So far in history, we didn't have enough to launch. If the volume we launch increases then a larger rocket flying often is helpful. We are at the peak of what a rocket the size of Falcon 9 can do. If you want full re-usability, the size helps you out quite a bit. And hauling the 'orbiter' into 'orbit' is only wasteful if you can't reuse it. I would argue what's actually wasteful is throwing the second stage in the ocean, even when it costs minimum 10million $, and likely more.
- DavidSJ 1y agoA larger rocket mitigates the effects of the rocket equation. The wet (loaded with propellant) to dry (empty of propellant) mass ratio is determined via the rocket equation to be the exponential of delta V divided by exhaust velocity. Certain parts of the rocket, such as the external tank structure, scale sub-cubically with the rocket's dimension, as do aerodynamic forces; whereas payload and propellant mass scale cubically. Hence if the rocket is smaller than a critical threshold size, the requisite vehicle structures are too large relative to its propellant capacity to permit the required wet:dry mass ratio to achieve the delta V for orbit. At exactly this size, the rocket can reach orbit with zero payload. As the rocket increases in size beyond this threshold, it is able to carry a payload which is increasingly large relative to the rocket's total mass.
- trklausss 1y agoAdded to that, Full-flow stage combustion engines are bigger, heavier, and more expensive, but are way more efficient. So a bigger rocket is the only option to get one of those onboard, and helps with taking more mass to orbit because they are more efficient than other options.
- perihelions 1y agoI don't believe there's any performance advantage for full-flow, which SpaceX alone is attempting. The only point is to lower the combustion temperature inside the turbines, at the expense of (much) higher flow rates through those turbines, in order to increase their lifespan. (There's a large difference between staged combustion generally and gas-generator engines, which throw away performance by dumping fuel out of the turbine exhaust).
- schiffern 1y agoSince the temperature limit of available materials is the fundamental limitation (even after making custom high-temp alloys), this allows them to maximize mechanical power from the turbopumps, which raises performance. We might imagine a conservative FFSC design which accepts very low temperatures in exchange for making it easy (low R&D cost) to reach high longevity. Raptor is not a conservative design, so it requires more R&D to achieve that longevity. https://www.youtube.com/watch?v=twnZYPdFgbU https://www.youtube.com/watch?v=twnZYPdFgbU
- inglor_cz 1y agoCompared to Starship, Falcon 9 may look like a medium rocket, but it is actually quite big, and Falcon Heavy is bona fide a heavy launcher, not just a hype-name.
- tim333 1y agoThe rationale was "Occupy Mars". https://in.mashable.com/science/85790/elon-musks-dream-to-occupy-mars-could-be-disastrous-if-rushed-says-award-winning-book https://in.mashable.com/science/85790/elon-musks-dream-to-oc...
- mlindner 1y agoWhat Saturn V and the Shuttle were trying to do pales in comparison to what the design goals of Starship are. If you were trying to repeat what those vehicles were doing you would've designed the launch vehicle significantly different.
- Robotbeat 1y agoNote that Saturn several stages on the test stand like this.