SpaceX just did a full duration test firing of a recovered 1st stage

Jeff Findley wrote on 8/8/2016 :
In article m,
says...

On 2016-08-06 10:47, Jeff Findley wrote:

In the pictures of the latest Falcon 9 first stage firings in Texas, you
can see a large weight attached to the top of the first stage.

OK. That makes a difference. In all pictures of test firings i had seen,
the engines were horizontal, and I don't think I ever saw a test firing
of a stage. (aka: they tested engines, not a full rocket).

Really? As far as I know, SpaceX has always tested its stages
vertically.

Saturn stages were tested vertically, IIRC. There's footage available
on those. (At what is now Stennis?)

NASA/ATK have done the horizontal for their most recent test for SLS.
There's a new camera that produces beautiful video of it:

URL:https://boingboing.net/2016/08/08/nasas-high-dynamic-range-st.html

[...]

/dps

--
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Well hung: curricle-hung in fact. Come sit by me and we'll test the
springs."
(Speculative fiction by H.Lacedaemonian.)

In article om,
says...

On 2016-08-07 08:02, Jeff Findley wrote:

If that's the case, they'd only use that stage 9 times, since only
having the ability to retank once is extremely limiting. Luckily,
they'd know this ahead of time and would plan accordingly.

There are very long lead times for launches. And if a stage is expected
to be available to customer X in 3 years for their launch, but months
before, that stage is declared "unusable" because it has been fueled too
many times, will SpaceX then give the customer a spare brand new stage
for that launch ?

Long lead times from traditional launchers stems from the long lead
times from their suppliers. Since SpaceX is so vertically integrated,
even for building new launchers, I doubt this is as big of a problem for
them.

As for reusables, presumably SpaceX will have many flown first stages to
choose from. They're all essentially identical, so swapping one for
another shouldn't be all that hard. So in the case of reusing first
stages, the "long lead times" ought to apply more to the second stage,
since it's expendable.

Similarly, if SpaceX plans to use a stage 10 times, but it fails its
landing after 2nd launch, there are 8 customers whose launches were
depending on this stage who are now stuck without a launch vehicle.

Presumably they will not stop producing first stages and will have at
least one spare available for a situation like this.

SpaceX will have to develop some sort of backup policies for when a
stage fails to be re-usable in order to still be able to make launches
on time. (rememeber that they also have to book the launch pad etc years
ahead).

This is why I suggeted some time ago that SpaceX will need to build an
inventory of used stages that are ready to for launch in order to
"buffer" any mishap that removes a stage from the flow unexpectedly.

Considering how many they've recovered already, they're well on their
way to doing this.

Another way to do business would be to sell only new stages at time of
signing commitment/contract, but "at last minute" offer a used stage
with discount IF one is available. If no used stages are available,
customer still launches on time with new stage. And if a used stage is
available, then it gets used, customer gets discount, and SpaceX has a
spare brand spanking enw stage it can sell to someone else.

It all depends on how reliable stage1 recovery/refurb becomes and how
predictable the inventory of used stages is.

Yes, the devil is in the details and they have a long backlog to work
off, so many of these issues are several years in the future.

Jeff
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JF Mezei wrote:

On 2016-08-07 08:02, Jeff Findley wrote:

If that's the case, they'd only use that stage 9 times, since only
having the ability to retank once is extremely limiting. Luckily,
they'd know this ahead of time and would plan accordingly.

There are very long lead times for launches. And if a stage is expected
to be available to customer X in 3 years for their launch, but months
before, that stage is declared "unusable" because it has been fueled too
many times, will SpaceX then give the customer a spare brand new stage
for that launch ?


Mr Mezei, you are VERY confused about how all this works.


Similarly, if SpaceX plans to use a stage 10 times, but it fails its
landing after 2nd launch, there are 8 customers whose launches were
depending on this stage who are now stuck without a launch vehicle.


You seriously believe they're going to 'schedule' stages decades ahead
of time? REALLY????


SpaceX will have to develop some sort of backup policies for when a
stage fails to be re-usable in order to still be able to make launches
on time. (rememeber that they also have to book the launch pad etc years
ahead).


Where do you get the idea that you "have to book the launch pad etc
years ahead"?


This is why I suggeted some time ago that SpaceX will need to build an
inventory of used stages that are ready to for launch in order to
"buffer" any mishap that removes a stage from the flow unexpectedly.


Where 'inventory' is some number around three or less. Just how many
launches do you think happen in a year?


Another way to do business would be to sell only new stages at time of
signing commitment/contract, but "at last minute" offer a used stage
with discount IF one is available. If no used stages are available,
customer still launches on time with new stage. And if a used stage is
available, then it gets used, customer gets discount, and SpaceX has a
spare brand spanking enw stage it can sell to someone else.


There are all sorts of possible business models. I doubt Elon Musk
needs your help in figuring them out.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn