JF Mezei wrote on Tue, 21 May 2019
20:04:31 -0400:

On 2019-05-21 06:42, Jeff Findley wrote:

Nope. In order to have enough political support in the Congress, the
pork-lifter will be part of the plan. Note that each of its planned
launches are specifically (prominently, actually) shown in the graphic.

When I saw the graphic, I had i my mind the SLS "icon" as being generic
since I was thinking NASA was open to using commercial rockets to get
this done by 2024.


Then why did you think they had a different rocket "icon" for some of
the flights?


So the graphic shows they can land a man on moon by 2024 by using only 3
porklifter flights (12 of 16 engines).


I think I said that already.


Also shows that each of the 3
components of the LEM will be sent to orbit separately (I guess this is
where the commercial launchers come into play) and I would assume much
of the testing will be done on flights that don't involve SLS.


You can probably assume that all of the testing for Artemis 'elements'
will take place in LEO an not involve SLS.

The graphic shows all of the SLS/Orion flights on it including the
"test" flights. There are no more. There is no money nor the time for
more (if the 2024 date is to be believed).

But the graphics also show generic rockets lifting the 3 components of
the "LEM". So I have to assume that there would be some earth orbit
flights in the 2021-22-23-24 time frame to test the LEM prototypes. (not
sure if manned or not).


Probably some of each; manned and unmanned.


Does Orion have a hatch compatible with Dragon2/station ?


Yes. It has a NASA Standard Docking Adapter. Why is it that you
refuse to look up even the most trivial things for yourself?


If so, could
they send crews on Dragon2 to dock with the "LEM" in LEO for humans to
test the lander and then return to earth in a Dragon? (or Constellation).


What does what Orion has have to do with anything? Orion doesn't dock
to anything other than Gateway.

Same thing will happen for SRB segments too. It's not yet clear what
will happen when those run out.

I was always under impression that only the engines were leftover
inventory from shuttle and limited in supply, and that the core stage
and SRBs were built new, based on designs for shuttle.


I believe you're correct here. I think the original intent was to use
SRB segments that were identical to those used with the Shuttle, but I
think that intent changed.

Did you even read the article? No, the LEM design won't be "dusted
off". It can't operate at sea level internal pressures, which is the
standard today.

Why would LEM-2 need to operate at 1ATM since it will never operate on
earth?


Why does ISS need to operate at 1 atmosphere since it never operates
on Earth? Nevertheless, it does. Why does Crew Dragon need to
operate at 1 atmosphere since it never operates on Earth?
Nevertheless, it does. Why does Boeing's Starliner need to operate at
1 atmosphere since it never operates on Earth? Nevertheless, it does.

Its walls are horribly thin and would not have the
factor of safety required today.

So what magic has happened to allow a lunar lander to now have much
heavier structure t please NASA standards? At the end of the day, won't
they be working with the same limitations on mass/fuel for the lander?


No, they won't. In fact, as I explained to you earlier, there is no
requirement that a Lander even use hypergolic engines and Blue
Origin's lander does not.


I am sure NASA wanted more shielding for the Apollow ERA LEM, but when
engineers come back with "no can do, all we can afford in the mass
budget is aluminium foil walls", then NASA has to bend the rules,
doesn't it?

That is why I asked if engine efficiently had radically changed since
then to allow much heavier vehicle to land on moon.


You asked that question because you made the horrible mistake of
assuming that a Lander Element would use some sort of hypergolic fuel.


And most importantly, the suppliers
are all gone. So you'd have to re-certify everything anyway!

Put blueprints on the RFP and suppliers able to build what is already
designed will bid and get contract.


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.


You save the years needed to design
something. The LEM's design was tested and went through all that
certification back in the 1960s.


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.


--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney