"M" wrote in message
...
What piqued my interest in that document was the reliability ratings
for manned spaceflight. I have no idea how they figured tehat the Ares
designs were safer than the Delta or Atlas.

It was, and still is, a "paper" vehicle, so the predicted reliability does
not have to have any relationship to actual demonstrated reality. For Ares
I, this is especially true when the heritage four segment SRB (only slightly
modified from the shuttle SRB) was later replaced with a new five segment
SRB. On top of that, for Ares V, they're exploring things like changing the
propellant formula and changing the SRB casings from steel (heritage shuttle
design) to composites (never flown on the shuttle). Ares V will be an all
new design using all new hardware. Others have commented, partly in jest,
that only the ET's spray on foam insulation will be the same.

This is a bait and switch of the highest order. The shuttle derived parts
of Ares have been thrown out the window. Even much of the shuttle ground
infrastructure will have to be upgraded or replaced due to the sweeping
changes made to Ares V (e.g. the size of the core is larger in diameter than
the shuttle ET).

I sincerely hope the Obama administration puts the floundering Ares program
out of its misery and demands that Orion be launched on EELV's, just as OSP
was supposed to be launched.

Jeff
--
"Many things that were acceptable in 1958 are no longer acceptable today.
My own standards have changed too." -- Freeman Dyson