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Jeff Findley[_6_] May 9th 21 02:38 PM

B1051 flies, and is recovered, for the 10th time
 

B1051 flew, and was recovered, for the 10th time in the early morning
hours. It lofted a new batch of Starlink satellites for SpaceX. SpaceX
has stated that they will keep flying boosters as life leaders on
Starlink missions. This allows the life leaders to fly without any
concerns from outside customers.

It seems like it wasn't long ago that some people were doubting that a
first stage could be flown and recovered 10 times. Yet here we are in
2021 and SpaceX is routinely flying recovered boosters.

Jeff
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These posts do not reflect the opinions of my family, friends,
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Jeff Findley[_6_] May 10th 21 12:11 PM

B1051 flies, and is recovered, for the 10th time
 
In article ,
says...

On 2021-05-09 09:38, Jeff Findley wrote:

It seems like it wasn't long ago that some people were doubting that a
first stage could be flown and recovered 10 times. Yet here we are in
2021 and SpaceX is routinely flying recovered boosters.



For the record, I wasn't doubting it could be done. I was saying that at
the time, it ws too early to claim SpaceX had proven it could fly 10
times since at the time that had only flown twice or 3 times, and with
no public info on how difficult the turn around/refurbishement would
involve (time/money).


High bypass turbofan jet engines are far more complex than liquid fueled
rocket engines and yet have become so reliable that twin-jets routinely
fly over oceans. Each GE-90 engine costs $24 million which is far more
than it costs SpaceX to make a Merlin or Raptor.

It's just that no other company besides SpaceX has focused on the cost
of launch and economical reusability. SpaceX is proving that space
travel doesn't need to be as hard or expensive as we've been told for
many decades.

I have no doubt that SpaceX will iterate Raptor into a reliable engine.
Starship and Super Heavy are still under development, but they too are
using iterative development. If all goes well, we'll see Starship prove
out in orbit cryogenic refueling and reuse of an upper stage. These are
both things that other companies could have been working on decades ago,
but chose not to.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

David Spain May 12th 21 03:28 AM

B1051 flies, and is recovered, for the 10th time
 
On 2021-05-10 7:11 AM, Jeff Findley wrote:
I have no doubt that SpaceX will iterate Raptor into a reliable engine.
Starship and Super Heavy are still under development, but they too are
using iterative development. If all goes well, we'll see Starship prove
out in orbit cryogenic refueling and reuse of an upper stage. These are
both things that other companies could have been working on decades ago,
but chose not to.

Jeff


There are essentially two issues here you raise with Old Space and a
third meta-issue that I think deserve a bit more reflection upon as to
why we ended up where we did relative to SpaceX.

I'll start with the second issue last. And that is the idea that 'other
companies' could have been working on reusable rockets decades ago. From
a technical perspective, prior to the 1980s I don't think so. Stuffing
the automation required into a rocket that didn't make it the size of a
Saturn just wasn't feasible. I use the automation in the Space Shuttle
as case one as to why. Somewhere in the mid to late 80's, from an
electronics perspective anyway (my area of knowledge) I think avionics
for controlled rocket reentry became feasible. And with designs like
DC-X we saw it was not only possible but realizable. And that was
McDonnell Douglas in the early 1990s. 3 decades back good enough? But
why did it end? That gets to my meta reason at the end.

The first issue has been discussed here before and that is the iterative
development model. SpaceX worked on a plan for itself based on prior
achievements but it didn't do this in a vacuum. Without COTS / CCDEV and
NASA funding it's not clear they could have bridged the gap between
Falcon 1 and Falcon 9. That was a big leap. That Falcon 1 achieved orbit
earned them cred with NASA that gained them the funding they needed to
continue. The commercial satellite contracts followed, but if memory
serves the com-sat folks were not ahead of NASA in line and none before
Falcon 9. NASA took care of the funding, but the iterative design work
and the dedication to reuse was a goal derived from a unique goal of
affordability that Elon baked into the company from the beginning. And
why is that important? Here is where we get to the meta-issue.

Until SpaceX came along, Old Space companies were more than happy to let
NASA and the USAF and to a lesser extent, DARPA determine what the goals
and objectives of their rocket programs should be. There was NO, ZERO,
ZILCH self-motivation. None of the Old Space companies had plans or
goals of their own for space exploration. Unlike their aircraft
divisions which were driven by commercial airlines, only the government
was in the drivers seat for rocketry. And because of that, it stagnated.
Well stagnated is not perhaps the right word. Because rocketry in the US
was not a private enterprise after WWII. After Goddard's experiments
there was no follow on. Perhaps in terms of weather observation there
might have been a glimmer of a commercial enterprise, but doubtful since
even before WWII weather observation and forecasting was considered a
domain of the government. The nearest idea I can come up with for
commercialization of rocketry was orbiting satellites as more reliable
communication relays than shortwave. But to fully leverage that
reliability would have required many, many LEO satellites and technology
that was unavailable to Goddard in his time. GEO would have been out of
the question until the science and engineering had advanced to a higher
state of the art. It's hard to image any one US company with pockets
deep enough to fund that effort.

The truly novel thing about SpaceX, is not that it built affordable
rockets. Not that it built re-usable rockets. Not that is uses
incremental designs. Nope the truly unique thing about SpaceX is that it
was the first rocket company to be -self-motivated-. The ideas and the
reasons for its designs came from Elon Musk's desire to get to Mars and
to figure out ways to enable that. Without the motivation of 'doing
space' in their own way, I don't think any of those breakthroughs that
followed would have taken place. NASA kept them alive at a key juncture
in their evolution, but now it's beginning to take shape, with
commercial contracts to keep it alive, and everyone else can come along
for the ride.

Dave



snidely May 13th 21 07:58 AM

B1051 flies, and is recovered, for the 10th time
 
Just this Wednesday, JF Mezei puzzled about:
On 2021-05-11 22:28, David Spain wrote:

Until SpaceX came along, Old Space companies were more than happy to let
NASA and the USAF and to a lesser extent, DARPA determine what the goals
and objectives of their rocket programs should be.


In fairness, when the customer specifies "new only" it really removes
incentive to develop re-usable since what will you re-use your used
rockets for?

Recall that NASA initial required "new only".

The self motivation you mentions )and I agree) is that SpaceX also has
aims to be its own customer (eg Starlink). So it did have a use for
used rockets for its own playground in space.

And once it proved itself, then NASA and commercial customers did turn
around and start to buy launches on re-uised falcon 9. (and NASA on
Dragon 2).

I would hope that ULA and ESA have had skunkworks to design re-usable
rocket because now that SpaceX has proven it can be done, it is but a
matter of time before the other guys lose a lot of business, leaving
only lobby-driver government purchases where the RFP specifies
performance that Falcon9 can't achieve to justify sending the business
to ULA.


ULA has promised that they will recover their first stage engines from
Vulcan "eventually".

Meanwhile, RocketLabs is on the doorstep of recovering Electron first
stages (they've done a wet pickup of one already). Blue Origin is
clearly serious about re-use, although New Glenn is seriously delayed b
trying to take Giant Steps (per Eric Berger in an NSF interview).

/dps

--
Yes, I have had a cucumber soda. Why do you ask?


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