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Akin’s Laws of Spacecraft Design

spacecraft.ssl.umd.edu

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Re: Akin’s Laws of Spacecraft Design

#141

Post by singleshot_ »

coldtea wrote: post #91
singleshot_ wrote: post #51

Earlier quoted context omitted.

> In software it's rather clear In software, I perceive there to be almost no separation whatsoever between design and use. I’m using windows 11 right now, and sometime in the next few days it will silently download software patches that were designed over the last few days to address situations not considered in the original design of windows 11. Software goes back and forth from the design process to active use pre…

I don't think that's the case, or all of the case. Windows might download patches and update components but the core OS design, is there for over 15 or more years, and ditto for most of the userland, when it doesn't go back to Windows NT times..

I completely agree with you insofaras parts of the design probably go back to NT. SBut some of the design won’t happen until next week. My interpretation of this is that the design process starts before use and continues until the end of the support lifecycle. I agree that there are some components that we think have been completely designed… but there might be a bug tomorrow in a “core” part of the OS that would require more design, and I don’t think this would surprise anyone if it happened.

I’m not saying necessarily that it’s continuous design, simply that we might return to the design phase at any time.

Re: Akin’s Laws of Spacecraft Design

#142

Post by Zandikar »

DennisP wrote: post #72
Zandikar wrote: post #8

Earlier quoted context omitted.

Err, what? Keyword there: "New". SpaceX still faces large costs and delays in developing new launch vehicles, including starship, which is delayed and unfinished btw, so no matter how you try to spin it, Starship is not (currently) a good example of SpaceX being an exception to the adage. Artermis 3 isn't exactly cheap afterall, and if you don't know what that is but know what Starship is, that proves the adage this…

> And when they were new, well, lots of delays and setbacks and costs as they kept accidentallying rockets trying to land them. They were launching just fine, it's just the landings where they blew up. This wasn't any sort of delay or major cost. Nobody else was landing rockets at all, they were just blowing them up intentionally. This is still the case today for all production orbital rockets other than SpaceX.

I'm agreeing with the adage in question (#'s 39 in OP) that designing any new rocket is going to be difficult or expensive, and if viable, it's better to use an existing. You acknowledge as much later in this thread:

> Well yeah almost everybody does on their first attempts.

The above poster I was responding to was saying the opposite. I was asserting that that's not true, that SpaceX is embracing the adage of not only "Don't reinvent the wheel" but "Hell, let's reuse the wheel".

Also, just because someone has the foresight to budget extra time and money for the inevitable failures/complications of an initial prototype, doesn't mean there weren't extra cost or time involved in the development of that product than if it had worked reliably like a mature, proven design would.

SpaceX has been killing it. I'm not criticizing. I'm just acknowledging these are some VERY basic tenants of engineering and product design PERIOD, no matter if you're making a stapler or a death star.

Re: Akin’s Laws of Spacecraft Design

#143

Post by Zandikar »

avmich wrote: post #16
Zandikar wrote: post #8

Earlier quoted context omitted.

Err, what? Keyword there: "New". SpaceX still faces large costs and delays in developing new launch vehicles, including starship, which is delayed and unfinished btw, so no matter how you try to spin it, Starship is not (currently) a good example of SpaceX being an exception to the adage. Artermis 3 isn't exactly cheap afterall, and if you don't know what that is but know what Starship is, that proves the adage this…

> The whole point of these two adages is that reusing an existing design is better than a new one. Yes, and that's put in doubt. Starship aims to improve on previous designs - in terms of affordability, that is, making human flights cheaper. This cheapness can't be realized with existing designs, so a new design becomes better in that regard. > SpaceX's REUSABLE rockets are great for a number of reasons yes, but by d…

> I don't know how good definition can exclude reusable rockets from being new

Because you're hung up on trying to tell me that the concept of reusable rockets is new in a grand history since while I'm trying to convey to you that the original Falcon 9 reusable rockets development ended over a decade ago.

> Do you know the difference between designing and using

You're the one struggling with that concept and the semantics around it, because you yet again prove my point while trying to argue it.

> SpaceX benefited immensely from using proven solutions

I'm glad you agree with the core point of my idea. Weird that you're so combative about it.

> Let me try to explain again my main point:

Don't bother, you missed the point of my comment entirely. Have a nice day.

Re: Akin’s Laws of Spacecraft Design

#144

Post by DennisP »

Zandikar wrote: post #142
DennisP wrote: post #72

Earlier quoted context omitted.

> And when they were new, well, lots of delays and setbacks and costs as they kept accidentallying rockets trying to land them. They were launching just fine, it's just the landings where they blew up. This wasn't any sort of delay or major cost. Nobody else was landing rockets at all, they were just blowing them up intentionally. This is still the case today for all production orbital rockets other than SpaceX.

I'm agreeing with the adage in question (#'s 39 in OP) that designing any new rocket is going to be difficult or expensive, and if viable, it's better to use an existing. You acknowledge as much later in this thread: > Well yeah almost everybody does on their first attempts. The above poster I was responding to was saying the opposite. I was asserting that that's not true, that SpaceX is embracing the adage of not on…

I guess I'm misunderstanding how SpaceX follows #39 in the form of "Whatever you do, don't develop any new launch vehicles," since SpaceX developed the Falcon 1, Falcon 9, Falcon Heavy, and is now working on Starship. There's probably been no point in their history when they weren't working on their next launch vehicle. Sure it's difficult, but just saying it's difficult is not the same as "whatever you do, don't do it."

I do think maybe NASA shouldn't develop any more launch vehicles, but I'm sure glad SpaceX is doing it and so are a bunch of newer companies.

Re: Akin’s Laws of Spacecraft Design

#145

Post by themadturk »

tonyarkles wrote: post #86
bryanlarsen wrote: post #28

Earlier quoted context omitted.

A decade is a short period of time by human-rated-spaceflight standards.

I mean… yes and no. The Apollo program started in 1961, had the first manned flight in 1968, and landed on the moon in 1969. Gemini started in 1961 and had two people in ‘65. Don’t get me wrong, I’m perpetually impressed by the things SpaceX is doing, but don’t let the fact that the rest of the industry has slowed down significantly convince you that SpaceX is moving faster than anyone ever has before.

For what it's worth, the Apollo program only had one bespoke launch vehicle, the Saturn V. Mercury used the Redstone (for sub-orbital flights) and Atlas, and Gemini the Titan, all of which were developed as ballistic missile platforms.

Re: Akin’s Laws of Spacecraft Design

#146

Post by themadturk »

jameshart wrote: post #61

I don’t feel like a field that has in its entire history only produced a handful of actual successful designs at all can possibly rate this kind of ‘world weary cynicism’ style of writing. Nobody has the experience or ability to be able to say ‘trust me I’ve built a few spaceships, this is the hard won truth of how it is’. There are exactly nine spacecraft that humans have ever flown in. Only the Mercury/Gemini/Apoll…

"A handful of actual successful designs"? Perhaps we should get the definition clear: a spacecraft in this context is any human-built vehicle flying in space, not just those that carry humans. There are thousands of earth satellites, extra-terrestrial orbiters, landers, rovers, and now even interstellar spacecraft that are very successful. They all needed launch vehicles.

Re: Akin’s Laws of Spacecraft Design

#147

Post by avmich »

Zandikar wrote: post #143
avmich wrote: post #16

Earlier quoted context omitted.

> The whole point of these two adages is that reusing an existing design is better than a new one. Yes, and that's put in doubt. Starship aims to improve on previous designs - in terms of affordability, that is, making human flights cheaper. This cheapness can't be realized with existing designs, so a new design becomes better in that regard. > SpaceX's REUSABLE rockets are great for a number of reasons yes, but by d…

> I don't know how good definition can exclude reusable rockets from being new Because you're hung up on trying to tell me that the concept of reusable rockets is new in a grand history since while I'm trying to convey to you that the original Falcon 9 reusable rockets development ended over a decade ago. > Do you know the difference between designing and using You're the one struggling with that concept and the sema…

No understanding :) .

Re: Akin’s Laws of Spacecraft Design

#148

Post by avmich »

themadturk wrote: post #145
tonyarkles wrote: post #86

Earlier quoted context omitted.

I mean… yes and no. The Apollo program started in 1961, had the first manned flight in 1968, and landed on the moon in 1969. Gemini started in 1961 and had two people in ‘65. Don’t get me wrong, I’m perpetually impressed by the things SpaceX is doing, but don’t let the fact that the rest of the industry has slowed down significantly convince you that SpaceX is moving faster than anyone ever has before.

For what it's worth, the Apollo program only had one bespoke launch vehicle, the Saturn V. Mercury used the Redstone (for sub-orbital flights) and Atlas, and Gemini the Titan, all of which were developed as ballistic missile platforms.

Not counting Saturn-I AND Saturn-IB?

Re: Akin’s Laws of Spacecraft Design

#149

Post by avmich »

bryananderson wrote: post #123
avmich wrote: post #30

Earlier quoted context omitted.

I'd consider development of Crew Dragon to be rather fast - because, in the condition of a private development, it wasn't done before. Comparing to other spacecraft developments, in late 1950-s there was a race, USA vs. USSR, to put a man in space "soonest", and it took Soviets ~3.5 years from the launch of the Sputnik to send Gagarin to orbit. So, just a few short years... and a large government backing. Still, give…

I think the difference between the “private” development of Dragon and the “government” development of Mercury is exaggerated. Like Dragon, the Mercury capsule was (mostly) designed and (entirely) built by a private contractor, McDonnell Aircraft. Like Mercury, Dragon was designed and built with input and strict oversight from NASA, including a contingent permanently on-site with the contractor. NASA always had total…

> Like Mercury, Dragon was designed and built with input and strict oversight from NASA, including a contingent permanently on-site with the contractor. NASA always had total visibility and the final say on everything.

I think that's not a contradiction to the Dragon being designed by a private company in a different, organizationally, way than Mercury was designed by a private company.

Re: Akin’s Laws of Spacecraft Design

#150

Post by jameshart »

themadturk wrote: post #146
jameshart wrote: post #61

I don’t feel like a field that has in its entire history only produced a handful of actual successful designs at all can possibly rate this kind of ‘world weary cynicism’ style of writing. Nobody has the experience or ability to be able to say ‘trust me I’ve built a few spaceships, this is the hard won truth of how it is’. There are exactly nine spacecraft that humans have ever flown in. Only the Mercury/Gemini/Apoll…

"A handful of actual successful designs"? Perhaps we should get the definition clear: a spacecraft in this context is any human-built vehicle flying in space, not just those that carry humans. There are thousands of earth satellites, extra-terrestrial orbiters, landers, rovers, and now even interstellar spacecraft that are very successful. They all needed launch vehicles.

“If you screw up the engineering, somebody dies” does not apply to unmanned spacecraft. In fact, unmanned spacecraft generally operate further away from humans than anything else does. When they go wrong the last thing that’s likely to happen is a human getting hurt.
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