SRB Economics

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

Regards,

Jens
--
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)

I think it was part of selling it as a reusable system to the uninitiated in
the government..
Cynic mode off.

Brian

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Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Jens Schweikhardt" wrote in message
...
hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

Regards,

Jens
--
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)

On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:
hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

On Aug 7, 2:32*pm, "Jorge R. Frank" wrote:
On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

out of round SRB casings were implicated in the challenger loss......

so reusing may have ultimately made it less safe...........

In article 3a12a115-f11d-4bf4-920e-49cf5071a2e5
@q15g2000yqk.googlegroups.com, says...

On Aug 7, 2:32*pm, "Jorge R. Frank" wrote:
On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

out of round SRB casings were implicated in the challenger loss......

This is a misleading statement at best.

so reusing may have ultimately made it less safe...........

Wrong!

There was plenty of data compiled on SRB field joint o-ring erosion on
flights prior to the Challenger disaster. The disaster did not happen
due to lack of adequate data. If the SRB's would have been completely
expendable (i.e., they sank to the bottom of the ocean after each
launch), then there would have been no flight data on o-ring erosion.

After the field joint redesign, inspections of flown RSRM's were crucial
to verify that the fixes to the design were actually working in flight.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

On Aug 11, 7:15*am, Jeff Findley wrote:
In article 3a12a115-f11d-4bf4-920e-49cf5071a2e5
@q15g2000yqk.googlegroups.com, says...







On Aug 7, 2:32*pm, "Jorge R. Frank" wrote:
On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

out of round SRB casings were implicated in the challenger loss......

This is a misleading statement at best.

so reusing may have ultimately made it less safe...........

Wrong!

There was plenty of data compiled on SRB field joint o-ring erosion on
flights prior to the Challenger disaster. *The disaster did not happen
due to lack of adequate data. *If the SRB's would have been completely
expendable (i.e., they sank to the bottom of the ocean after each
launch), then there would have been no flight data on o-ring erosion.

After the field joint redesign, inspections of flown RSRM's were crucial
to verify that the fixes to the design were actually working in flight. *


I can't believe you're bothering to respond to Chicken Little. Oh
well. Anyways, Arianespace every now and then recovers the Ariane 5
SRBs to do just that. Ironically enough, those are about the most
reliable part of the whole system, and have never contributed in the
slightest towards any of the missions castrophic failures, nor been a
problem in any other way worth mentioning. As we've seen with Ariane 5
and post-Challenger STS, when you recover the SRBs and actually pay
attention to the data, the system works just fine.
-Mike

On Aug 11, 10:15*am, Jeff Findley wrote:
In article 3a12a115-f11d-4bf4-920e-49cf5071a2e5
@q15g2000yqk.googlegroups.com, says...







On Aug 7, 2:32*pm, "Jorge R. Frank" wrote:
On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

out of round SRB casings were implicated in the challenger loss......

This is a misleading statement at best.

so reusing may have ultimately made it less safe...........

Wrong!

There was plenty of data compiled on SRB field joint o-ring erosion on
flights prior to the Challenger disaster. *The disaster did not happen
due to lack of adequate data. *If the SRB's would have been completely
expendable (i.e., they sank to the bottom of the ocean after each
launch), then there would have been no flight data on o-ring erosion.

After the field joint redesign, inspections of flown RSRM's were crucial
to verify that the fixes to the design were actually working in flight. *

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011- Hide quoted text -

- Show quoted text -

I stand by my statement, since the boosters could of been recovered
but not reused.

and in the case of challenger the casings were a bit out of round.
which was a added suspect in the challenger loss.

besides which nasa managers had the data of o ring issues but did
nothing with it

On 7 Aug 2011 10:00:13 GMT, Jens Schweikhardt
wrote:

hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason?

At high flight rates (the originally envisioned 50 flights per year,
but 24 was probably the max possible with existing infrastructure)
recovering and reusing the SRBs would have made economic sense. At the
low flight rate which actually happened (6-8), it was barely a
breakeven operation, but the inspection/safety considerations kept SRB
recovery and reuse in the flow.

Brian

I don't think this point can be emphasized enough. The ability to inspect
used components is a huge part of making a system safer.
(Of course ACTING on the data is also equally important.)




"Jorge R. Frank" wrote in message
...

On 08/07/2011 05:00 AM, Jens Schweikhardt wrote:
hello, world\n

I am wondering why the SRBs were designed to be reusable. What's the
specific economic reason? The cost of recovering and refurbishing the
empty hulls was certainly not negligible. So what was that precious part
that was more economic to recover than to manufacture? Was it expensive
rare earth metals in the hull, turbo pumps, or something else that's so
valuable?

None of the above. What was precious was the ability to inspect the SRB
itself, which could provide clues to problems with SRB design and
production for crew safety (and could have saved the 51L crew had the
warning signs been taken more seriously at the time).

The cost of discard vs reuse was a wash. The reason it was done was crew
safety.

"Greg \(Strider\) Moore" wrote
in :
# I don't think this point can be emphasized enough. The ability to inspect
# used components is a huge part of making a system safer.
# (Of course ACTING on the data is also equally important.)

But you could have recovered and inspected the SRBs *without* reusing
them. After all they've been subject to a lot of mechanical stress, high
temperature, low pressure and salt water. Why run the risk of using
out-of-round hulls, microcracks in metal, corroded materials and all
that?

Regards,

Jens
--
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)