View Single Post
  #21  
Old May 23rd 19, 12:16 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default NASA?s full Artemis plan revealed: 37 launches and a lunar outpost

In article ,
says...

On 2019-05-21 23:08, Fred J. McCall wrote:

Except it doesn't work that way. Try to buy an Intel 80486 processor.
You can't. And that will apply to almost every part in the LEM
blueprints.


Since they need hardened CPUs and RAM, they'll use whatever is available
on the market (usually older vintage) or special order some. I am not
advocating they use the same computers as on the 1960s LEM. I even
mentioned they could run this on an iPhone if they wanted it.

But for structures, I have to wonder why they wouldn't re-use the
general design of the LEM, as ugly as it was since it fit the purpose.


So you're advocating for a new LEM, not one that is made to the exact
specs of the 1960s. Do you see how you're already sliding down a
slippery slope? By the time you're done replacing old parts with new
ones made with modern manufacturing techniques, your "proven" LEM design
will actually be a completely new design!

But all your parts are going to be from new vendors using new assembly
lines. You're going to have to certify everything as if it was a
brand new vehicle.


Yes, but re-using a design you know has worked well saves you on the
design stage.

When totally new, you have to certify the design will work and then
certify the hardware as built meets the design. When re-using an
ecxisting design, you only have to certify the new hardware fits the design.


Bull****. You have to also certify the entire *system* design will work
with all those new parts. It's not good enough to design and test the
components and *hope* that they all work together. Almost all of the
hard problems in engineering are at the system level, not the component
level.

Jeff

--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.