JF Mezei wrote:

On 2017-04-29 03:47, Fred J. McCall wrote:

Why would it? If you're going to take a slide, the last thing you
want to do is make it even bigger and higher risk, which is what
flying EM-1 manned would do. I'd say it LOWERS the odds that it will
be manned.


Consider 2 separate development tracks: one for the ship, one for the
manned portion (Capsule interiors, ECLSS etc).


Consider Pure ****ing Magic (PFM), because engineering development and
integration efforts don't quite work like that.


Ship portion is late, but manned portion is on time. So what if the
manned portion ends up being ready by the time the ship portion finally
gets ready ?

If ship was initially supposed to be ready 2 years ahead of manned, but
there is a 2 year delay with the ship, then by the time the ship is
ready, the manned portion woudl also be ready.


Then your schedule slides because all your integration and test slides
to the end of the longest component.


Now, if both tracks are late, then things remain as originally planned
since ship, despite delays, is still ready before manned.


No, they don't do that at all. Everything has slid. The order things
are done in has probably changed. Requirements have been dropped in
order to try to make schedule (not added).

EM-1 will not be manned unless it slides out to 2021, about where EM-2
is currently scheduled. So you can have EM-1 unmanned if you slide to
2019 and adding the manned requirement adds at least another two year
slide.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson