"JF Mezei" wrote in message ...

On 2018-02-20 06:34, Jeff Findley wrote:

The shuttle was a magnificent machine, but it was expensive as hell and
held NASA back with its high fixed costs.


Considering how SpaceX is revolutionizing pricing by orders of magnitude
because it can re-use stages, it boggles the mind that the Shuttle
couldn't be competitive.

From a cheap turn-around point of view, where did the shuttle lose? Was
it the cost of turning around SRBs ? new ET for every flights ?
Hypergolics in the orbiter? tiles ? or the SSMEs ?

(if answer is "all" which were substantial?

Jeff gives a pretty decent answer. It really comes down to:
"It wasn't designed to be cheap to fly. It was designed to be cheap build."

For example, boosters that were liquid fueled and used perhaps the proven
F-1 and could be refurbished at the Cape.
(and probably would have prevented Challenger).
Even if you ignore other factors, not having to ship boosters 2/3rds of the
way across the country and back would save you money.
Instead of landing like the Falcon 9, most likely, they'd have been fly-back
and landed on the shuttle runway.
The ET was probably "cost effective".
Moving away from hypergolics would have had a different effect. One of the
issues with hypergolics is that during any processing you had to basically
lock down the shuttle processing facility. This really screws with your
ability to get work done. Remove that issue and you can process the shuttle
faster. Process faster, means fly faster.

Settle for a lighter/smaller shuttle. This gives you other options for the
heat shield.

Design for better processing of on-board items. Make everything electronic
(and mechanical) easier to remove and services. Adds some mass for
connectors, but again, speeds up processing.

Basically design it so you really CAN refly every 2 weeks. Or even every 4
weeks. With 3 shuttles available, every 4 weeks gives you 36 flights a year
(as opposed to 9-12).
Now, you might still have the same standing army (but my suspicion is if you
had built in reusability from the beginning you could cut that in 1/2.). But
spread over 3x as many flights.

So even if total fixed costs remained the same, you'd be looking at an
incremental cost of about $100M or, if you prefer Jeff's costing over the
cost of the program, under $500M (vs the close to $1.5B/flight).

Basically, THIS is what you want the Orbital Processing Facility to look
like:
https://en.wikipedia.org/wiki/Critic...singVision.jpg

Not

https://en.wikipedia.org/wiki/Critic...singActual.jpg

Basically though, too much politics. This was sort of inevitable given the
way NASA was headed (and partly conceived).

A private investor, like Musk, doesn't need to spread the pork around. He's
going to spend energy on designing the cheapest to fly system he can.
NASA is going to spend energy on making the pork is spread.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/