In article ,
says...
Considering SLS uses conventional already developped tech, are there
really technical reasons why this thing can't fly yet? I get the
impression that this pork programmed is designed to last as long as they
possibly can to maintain jobs as long as tghey possibly can, so delays
benefit politicians.

They have tested the SSMes many times aready. Any indication that there
are problems with them with their new controllers? or are they ready for
flight and NASA just keeps testing them as a token "deliverable" to show
Congress ?


Forgot to reply to the above (from JF).

Part of it is Boeing's incompetence due to the cost plus nature of the
contract. Part of it is that it's not really shuttle derived. Like I
said, the only things being reused are the SSMEs and those got new
engine controllers and are being used in expendable mode at a higher
thrust setting than they were used on shuttle missions.

All of the shuttle ET tooling was destroyed. The SLS core stage is
being built with all new tooling. And as I said in the last post, the 5
segment SRBs are really a new design that only shares the steel casings
with the shuttle's four segment SRB design. Everything else has been
redesigned for the larger size of the booster.

The Delta IV derived upper stage is the most ready to fly. After that,
the SSMEs are the most ready to fly out of the entire design, IMHO. I
don't think the SRB has been test fired again after the test that blew
the nozzle into chunks. The core stage has not been test fired yet.
That's the "Green Run" that's been talked about a lot in the space news
press.

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.