41–50 of 159 posts
Earlier quoted context omitted.
What's a line of blame?
I take it to mean when blame is being aimed you are not in the line of fire.
"at a project's beginning, define rules such as 'if component X explodes, it is team ABC's fault'".
context:
> 37. (Henshaw's Law) One key to success in a mission is establishing clear lines of blame.
Number 13. Design is based on requirements. There's no justification for designing something one bit "better" than the requirements dictate. Isn't that the margin for error? I want to go up in a ship that's a little better than the absolute minimum.
Earlier quoted context omitted.
> Both were late What was the "determined" date to have them ready? How do you know they were late? Judging by Elon's estimates? > I wouldn't say that Falcon was built expressly for humans You know of course that requirements for the rocket to launch people are different from the rocket to launch only cargo? There were cases when non-human-rated rocket became human rated (at least Proton), but these days it's better…
> What was the "determined" date to have them ready? How do you know they were late? Judging by Elon's estimates? Crew Dragon was approximately 3 years late, from the original planned launch date of 2017 to the actual date of 2020. Given that the contract for the missions were awarded in 2014, it's a miracle that things have proceeded at the pace they have. > You know of course that requirements for the rocket to lau…
I knew #36 and have used it in the context of software engineering. But much of the rest is similarly applicable. > #36 Any run-of-the-mill engineer can design something which is elegant. A good engineer designs systems to be efficient. A great engineer designs them to be effective.
"boss, I have finished the task. But this time, I activated great engineer mode, hence the result is not only elegant, but efficient and effective."
Hi. I'm Henshaw of Rule 37. AMA.
What's a line of blame?
If there are unclear boundaries between responsibilities, things will fall through the gaps when one group assumes another will take care of something.
Earlier quoted context omitted.
> Both were late What was the "determined" date to have them ready? How do you know they were late? Judging by Elon's estimates? > I wouldn't say that Falcon was built expressly for humans You know of course that requirements for the rocket to launch people are different from the rocket to launch only cargo? There were cases when non-human-rated rocket became human rated (at least Proton), but these days it's better…
> What was the "determined" date to have them ready? How do you know they were late? Judging by Elon's estimates? Crew Dragon was approximately 3 years late, from the original planned launch date of 2017 to the actual date of 2020. Given that the contract for the missions were awarded in 2014, it's a miracle that things have proceeded at the pace they have. > You know of course that requirements for the rocket to lau…
Could you imagine if NASA mandated that SpaceX be the launch platform for Boeing's capsule?
Earlier quoted context omitted.
Falcon 9 (plus Dragon) is the definitive counterexample. The jury on Starship remains out.
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…
Number 13. Design is based on requirements. There's no justification for designing something one bit "better" than the requirements dictate. Isn't that the margin for error? I want to go up in a ship that's a little better than the absolute minimum.
Are the Martian rovers outliers to this rule?
>I want to go up in a ship that's a little better than the absolute minimum.
This makes me think of the "this was built by the lowest bidding contractor" quote
The R100 design was "competing" with the design for the R101; both design teams were simultaneously tasked with constructing a viable airship to make a long-range trip (in the case of R100, crossing the Atlantic in 78 hours, which was a remarkable achievement for the time). The difference was that the R101 project was state-owned whereas the R100 was privately-owned.
R101 crashed and burned in France, en route to India on 5th of October, 1930, likely due to structural issues damaging the airships gasbags, of which the only survivors were those lucky enough to be in the engine cars.
In the autobiography, Norway describes how the difference in program management led to the disaster. There are a lot of factors that led to the crash, as you might imagine, but one of the points he makes is that the publically-owned project was not held to strict requirements in its design process. The privately-owned R101 had a strict contract that they needed to complete, with a tight budget to complete it. They had constraints. Whereas the public-sector project was allowed to continually revise their design as they went, making many successive rewrites and changes without much structure. In particular, they cut the ship in half and rebuilt it at one point in it's development. And when they arrived at the end of their development cycle, they had no leeway to maneuver because they had a lot of public money wrapped up in the project, along with a lot of public visibility and responsibility, pressuring them into rushing the launch without complete trust in their design, and into terrible weather conditions.
*13. Design is based on requirements. There's no justification for designing something one bit "better" than the requirements dictate.*
Decide/envision your outcome, and set your constraints correspondingly early on in development, aligned with realistic expectations of resources, folks.
To underline my point, here's a quote from the Wikipedia page.
"Shortly before R101's flights in June 1930, the Cardington [R101] engineers tentatively suggested that the long flights to Canada and India might be postponed until 1931 on the grounds that neither of the two airships was fit to make a lengthy flight at their current developmental stage. The R100 team replied that their airship was perfectly capable of flying to Canada, and that the Canadian flight was a part of their contract."
R101 did not have a contractual obligation to meet, but did not want to outright state they needed more time, lest admit defeat. R100 had requirements that they needed to meet, which they were ready to meet, as they had them written from the start in clear. R100 launched successfully. R101 was forced to launch to compete before it was ready, due to this "spontaneous requirement". R101 burned for it.
Number 13. Design is based on requirements. There's no justification for designing something one bit "better" than the requirements dictate. Isn't that the margin for error? I want to go up in a ship that's a little better than the absolute minimum.