Friday, October 18, 2013

My broken record

Is playing again at Rand's blog. I should add that the article he refers to is one of the best in highlighting the mess of SLS and the opportunity costs lost.

1 comment:

Anonymous said...

SLS is only bad if you evaluate it as a space launch system. But it's absolutely magnificent if you evaluate it as a multi-billion dollar enormous paperweight.

Seriously though, many of the criticisms of SLS miss a huge issue; the engines. It's using leftover SSME's (RS25-D) engines from the shuttle program. There are about 16 of them. So, the plan is that they'll develop an expendable low-cost simplified version of this reusable high performance engine. They are calling it the RS-25E. But, they've done basically nothing on it. Now here's the kicker; they are assuming that they can get the same performance out of the simplified RS-25E as they got out of the D model.

Think about that... the truth is, they probably can't. What that'll mean is a payload hit, a major one. If that happens, SLS is probably going to have roughly the same escape velocity payload as Falcon heavy's second generation with the Raptor methane engine on the upper stage.

The engine issue isn't the only one where SLS's payload estimate seems overly optimistic, but it's a big one.

And if the payload is smaller than advertized, that means all those outragiously high cost-per-pound price estimates for SLS are wrong, very wrong, because they understate the cost.

Arizona CJ