"JF Mezei" wrote in message
web.com...

On 2017-10-28 15:38, Jeff Findley wrote:

So what? They're doing better at turning around recovered first stages
to be re-flown faster than any of the competition

The only "re-use" competition is the Shuttle and it wasn't a commercial
endeavour.

Landing a just launched stage doesn't save any money. It costs money.

Launching a payload with a re-used stage 1 is what saves you money.


The Block 5 has improvements to the design to help with reuse.

One could infer that those improvements are a sign that the current
Falcon 9 is harder to re-use as the cheer leaders say it is.

No, this is how engineering is done. Incremental steps as you learn more.


SpaceX
will only get better at this while the competition (aside from Blue
Origin, who's still working on the BE-4 engine for New Glenn) are not
even trying to reuse anything.

The argument isn't whether SpaceX is ahead or other or not. The mere
fact that they have demonstrated they can land a stage, and have re-used
at least 1 stage means they are way ahead of anyone else.

But that doesn't mean that they have proven that they can already
quickly turn around every landed Falcon 9.

They've demonstrated the concept, they've demonstrated they can land
stages, they have demonstrated they can refly at least 1 stage. But
havent yet demonstrated they can have short turn around between landing
pad and launch pad such that it allows high launch rate OF RE-USED STAGES.

Just because it is very likely that they will be able to turn these
around quickly doesn't translate to them having demonstrated it.

Just because there are improvements coming that will make future refurb
even easier doesn't mean that they have demonstrated it already.



The crush core is more likely to be used up on high energy launches.

On a commecial aircraft, after a hard landing, the aircraft is put "off
line" for inspections. So I would assume that if a crush core gets used
up fully, the stage may require more time to be certified for reflight.


I am not questioning the huge game changing advantage SpaceX has in
having developped re-usable stages. Am not questioning that they have
proven they can land stages and re-use at least 1.

What they haven't proven yet is the ability to ramp up refurbishement to
do quick turn around from landing pad to launch pad. It's too early for
them to have demonstrated it.

Give them time. But I was curious.
Booster 1035 will have reflown in less than 6 months.
Looking at the list, right now it looks like 6 months on average.
That's similar to the first few flights of the shuttle.

But, Musk's goal is to do a reflight within 24 hours. I suspect he'll do it
within the next year or two, if only as a demonstration.

I suspect we'll see 1-2 weeks between reflights down the road.


--
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/