In article . com,
says...

On 2015-12-29 07:02, Jeff Findley wrote:

With the shuttle, NASA designed the thing to only fly with people on
board, so its first test flight was manned by Crippen and Young (if
memory serves). With Orion, it looks like we'll get a couple of
unmanned test flights (including the development flight that was on
Delta IV).


Until there is a functional service module, is there a point in putting
humans in a "throw the ball up and watch it fall" tests ?

The service module test article, provided by ESA, is at NASA's huge
vacuum testing facility (here in Ohio) right now. I'm sure it shares a
lot of hardware heritage with ATV.

Orion itself can't go to orbit until there is a de-orbit engine
attached, right ? And that requires functional service module, right ?

SLS is still two to three years away from first flight. NASA says "No
later than November 2018", but in my book it's more like no earlier than
November 2018 given how slowly the program has progressed over the
years.

The service module will no doubt be ready for its first test flight by
the SLS first flight.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer