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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

#91

Post by coldtea »

singleshot_ wrote: post #51
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…

> 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..

Re: Akin’s Laws of Spacecraft Design

#92

Post by coldtea »

idlewords wrote: post #5
avmich wrote: post #4

This is definitely the wisdom of ages, but some points do show some age. 39. (alternate formulation) The three keys to keeping a new human space program affordable and on schedule: 1) No new launch vehicles. 2) No new launch vehicles. 3) Whatever you do, don't develop any new launch vehicles. Recent SpaceX developments, Starship in particular, put some doubts on this one.

Let's put this comment in the comment cellar for a few years, to fully develop the tannins, and then see how it has aged. Starship progress is a little ways away from proving this adage wrong.

>Starship progress is a little ways away from proving this adage wrong

Yeah, and will perennially be so

Re: Akin’s Laws of Spacecraft Design

#93

Post by coldtea »

avmich wrote: post #22
inamberclad wrote: post #9

Earlier quoted context omitted.

That's still going to be late and over-budget.

Late comparing to what? Maybe SpaceX will not make it ready for NASA's return to the Moon flights as it was planned. However those dates don't look too serious to me - what's the justification for them? I suspect they were specified fully understanding they can easily slip right. Over-budget - what's the planned budget? I suspect Elon Musk himself doesn't have pre-approved specific budget to develop Starship, which m…

So, it's not late because the dates weren't serious to begin with?

Re: Akin’s Laws of Spacecraft Design

#94

Post by GuB-42 »

avmich wrote: post #4

This is definitely the wisdom of ages, but some points do show some age. 39. (alternate formulation) The three keys to keeping a new human space program affordable and on schedule: 1) No new launch vehicles. 2) No new launch vehicles. 3) Whatever you do, don't develop any new launch vehicles. Recent SpaceX developments, Starship in particular, put some doubts on this one.

SpaceX never done a human space program, they are purely about making launch vehicles that, after they have seen substantial development, are taken into consideration by NASA for a human space program.

Furthermore, Starship is not a launch vehicle in the context of Artemis, it is to be used as a lander. The launcher that will launch humans is still SLS (which fits point 39 perfectly).

And SpaceX never was on schedule. Starship development is seriously impressive, but the planned first launch for "BFR" was 2022, and we only got an expectedly failed test flight in 2023. We have absolutely no idea about when it will launch its first payload. Probably not before 2024. The first manned mission (which is not a full manned launch) is planned for 2025 (2 manned launches originally planned for 2024), and is extremely unlikely to make it by that time.

Still excellent by space standards, but doesn't contradict point 39.

Re: Akin’s Laws of Spacecraft Design

#95

Post by visviva »

jameshart wrote: post #85
visviva wrote: post #76

Earlier quoted context omitted.

What makes you think this is limited to human-rated spacecraft?

The multiple references to human spaceflight?

As far as I can tell, only 1 out of the 45 laws (#45) potentially refers to human spaceflight.

Re: Akin’s Laws of Spacecraft Design

#97

Post by yellowapple »

GuB-42 wrote: post #94
avmich wrote: post #4

This is definitely the wisdom of ages, but some points do show some age. 39. (alternate formulation) The three keys to keeping a new human space program affordable and on schedule: 1) No new launch vehicles. 2) No new launch vehicles. 3) Whatever you do, don't develop any new launch vehicles. Recent SpaceX developments, Starship in particular, put some doubts on this one.

SpaceX never done a human space program, they are purely about making launch vehicles that, after they have seen substantial development, are taken into consideration by NASA for a human space program. Furthermore, Starship is not a launch vehicle in the context of Artemis, it is to be used as a lander. The launcher that will launch humans is still SLS (which fits point 39 perfectly). And SpaceX never was on schedule…

> SpaceX never done a human space program, they are purely about making launch vehicles that, after they have seen substantial development, are taken into consideration by NASA for a human space program.

Crew Dragon is not a launch vehicle.

Re: Akin’s Laws of Spacecraft Design

#99

Post by yellowapple »

coldtea wrote: post #93
avmich wrote: post #22

Earlier quoted context omitted.

Late comparing to what? Maybe SpaceX will not make it ready for NASA's return to the Moon flights as it was planned. However those dates don't look too serious to me - what's the justification for them? I suspect they were specified fully understanding they can easily slip right. Over-budget - what's the planned budget? I suspect Elon Musk himself doesn't have pre-approved specific budget to develop Starship, which m…

So, it's not late because the dates weren't serious to begin with?

You can't be behind schedule and over budget if you have neither a schedule nor a budget.

rollsafe.jpg

Re: Akin’s Laws of Spacecraft Design

#100

Post by monkeydreams »

karaterobot wrote: post #58

I have a subset of these printed out and tacked to a cork board in my office, and I refer to this website a few times a year. Very, very good stuff. This one in particular was a big influence on me when I moved from engineering to design. It expressed what I'd felt but hadn't put into words. Not just the look, but nearly every aspect of a project is de facto path dependent, so you want to be as far upstream as possib…

> If you want to have a maximum effect on the design of a new engineering system, learn to draw. Engineers always wind up designing the vehicle to look like the initial artist's concept.

This is a key truth that works in a number of contexts. If you want to make sure the new security policy won't break your workflows, offer to write the first draft. If you want to ensure the new automation system will work for your team's requirements - offer to chair the requirements meetings.

Humans are lazy, though some of them move around a lot in an attempt to mask this. If you get in early and set the parameters of an enterprise, you influence every iteration of that enterprise until its dying day.

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