In article om,
says...

On 2016-12-10 14:43, Jeff Findley wrote:

After having landed in the ocean, and having spent a good
number of hours floating in salt water the spacecraft will
have to be stripped back to the bare pressure hull to get
rid of the salt.

I assume that engineers knew this all along, but NASA management had to
continue to pretend it would be reusable?

Of course, but NASA is risk averse these days and has ended up with a
design very much like the Apollo CSM when it comes to the Orion, its
service module, its solid escape tower, and etc. And Apollo wasn't at
all reusable after its swim in salt water. Salt water is *very bad* for
most aerospace grade materials like aluminum alloy.

What would it take to get Orion to land on land? Just stronger retro
rockets for final approach? (and appropriate software). Or is the
structure just not designed for this ?

Orion does not have "retro rockets for final approach". It lands via
parachutes, just like Apollo.

Would they need new seats? Or ate the current designs OK for land landings?

Seats are the least of your problems here. Orion is simply not designed
to land on land, except in the case of an emergency/contingency landing.
And in that case, expect the capsule's structure to be permanently
damaged while protecting the passengers (like a car crash).

I am trying to understand whether the re-usability was canned before the
capsule was architected, or whether it was designed to be re-usable, but
somewhere along the process, they gave up and went for water landing.

They're still saying it will be reusable, but when you look at the
details, it will actually be stripped down and rebuilt. That's not
"reusable" in my book, but NASA will insist that it is.

They did much the same with the "reusable" space shuttle SRBs. Those
things were stripped to their bare steel casings and rebuilt. And the
costs were about the same as it would have been just to build new steel
casings for newly built SRBs.

With regards to salt, isn't the ablative shield pretty much water tight,
so only the exposed portions would be vulnerable (radar, retro rockets
and what not).

The holes in the thing aren't. Salt water will get into the thruster
chambers and into any little crevice and crack.

It's not impossible to refly, but it will take replacing the heat
shield, thrusters, and just about everything outside the pressure vessel
after every flight.

Different slant: have the components inside the capsule (ECLSS,
electronics, power etc) been designed to be easily taken out and
installed in a new capsule ?

As the person I quoted said, yes, many components *inside* the pressure
vessel that will not come into contact with salt water can be reused.

I would hope NASA learned its lesson with the early SSMEs that were not
designed to be easily taken out for maintenance.

Yea, well, that was a result of having to put LOX/LH2 main engines in a
small space on the orbiter. Like shoving a 4 cylinder engine and
transmission inside the front of a compact car. It's a tight fit and
not at all easy to work on.

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.