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Old November 20th 17, 03:09 AM posted to sci.space.policy
William Mook[_2_]
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Default Were liquid boosters on Shuttle ever realistic?

On Monday, November 20, 2017 at 11:28:33 AM UTC+13, Fred J. McCall wrote:
Jeff Findley wrote:

In article ,
says...

Were liquid flyback boosters for the Shuttle ever realistic?

YES

http://www.ok1mjo.com/all/ostatni/sp...98377 048.pdf

Recovery costs would be dramatically reduced, along with
propellant costs. LOX is $0.10 per kg and Kerosene is $0.40
per kg, whilst Polybutadiene and Ammonium Perchlorate costs
well over $2 per kg. Recovery from the sea, versus landing
at an airport, makes the SRBs way more costly than LRBs, the
SRB has far lower performance than the LRB with the LRB
being nearly twice as efficient, the cost of refuelling and
handling the SRB is 10s times more costly than LRB, the
ability to throttle the LRB makes things far safer for the
LRB than the SRB, structure weight is far lower for the LRB
than the SRB, increasing payload to orbit, haha - this is
just the short list.


You are completely ignoring development costs.


Magic Mookie Math and 'Asshole' Accounting (where he pulls numbers out
of his ass) frequently ignore lots of things.


NASA never received
development funding for liquid fly-back boosters. And with NASA's cost
models (especially back then), it would have cost many billions of
dollars to develop. The politicians were never willing to fund that
kind of development, especially with the huge political support that
ATK has always enjoyed.


ArianeSpace studied the idea of replacing the SRBs on Ariane 5 with
liquid flyback boosters. They concluded the development would take 10
years and be hideously expensive (and EU cost models tend to be much
worse than NASA's).


Supporting SRBs also meant indirect support for the supply chain
necessary to develop and produce next generation ICBMs. Politically, it
was hard to disentangle the shuttle program from the support of that
supply chain. This was not something expressed loudly in the press, but
I am arguing the pressure was there, behind closed doors.


This was pretty much common knowledge at the time when they were doing
the original development work. SLS was originally scheduled to get
liquid boosters to replace the SRBs around 2024. That development
slid to the latter part of the 2020's and it now looks like the
'internal plan' is to use a new ATK SRB called 'Dark Knight' rather
than liquid boosters based on the J-1B motor.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw


http://hydrogen-peroxide.us/uses-bip... tle-1999.pdf

http://www.ok1mjo.com/all/ostatni/sp...98377 048.pdf

https://www.sciencedirect.com/scienc...9457659090062P

Three engines were considered as part of the study I provided. Hydrogen peroxide and kerosene are an interesting possibility as well, given the high density of the propellaht - which exceeds the solid rocket booster in performance and matches it in propellant density.