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A different direction after Challenger loss



 
 
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  #1  
Old February 18th 13, 01:18 AM posted to sci.space.shuttle
Bob Haller
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Posts: 3,197
Default A different direction after Challenger loss

On January 28, 1986, challenger was lost after the O ring failure.

Now lets consider a different NASA path. it became all too clear the
shuttle had no launch boost escape.

So nasa still resumed flying but did a general shuttle redesign.

They moved away from the solids, and designed a compatible liquid
flyback booster with more power. One of the uses of more power was a
jettisonable crew compartment. giving the shuttle what it should of
never flown without, launch boost escape. Other redesigns would of
included elminating the APUs that used hydrazine. All those would be
great to have, and saved big bucks on processing. Eventually upgraded
TPS, going to blankets rather than individual tiles. Plus changes to
extend the shuttles life in orbit. Upgrading tires etc. Shuttle C
cargo would of been a natural outgrowth of the upgrades and a larger
more powerful flyback booster could of covered heavy lift

The costs of operation could of been cut enough to pay for the
upgrades. Plus perhaps additional new orbiters could be built slowly
over time. Keeping the design fresh. Older orbiters could of been
retired to museums as they were replaced.

The big mistake was freezing the basic design after challenger.

The shuttle could of been a safer much more capable vehicle if it
wasnt starved for cash......

  #2  
Old February 18th 13, 03:16 AM posted to sci.space.shuttle
Jeff Findley[_2_]
external usenet poster
 
Posts: 1,388
Default A different direction after Challenger loss

In article dcdf2f03-ac1c-4cd5-ad69-
, says...

On January 28, 1986, challenger was lost after the O ring failure.

Now lets consider a different NASA path. it became all too clear the
shuttle had no launch boost escape.

So nasa still resumed flying but did a general shuttle redesign.

They moved away from the solids, and designed a compatible liquid
flyback booster with more power. One of the uses of more power was a
jettisonable crew compartment. giving the shuttle what it should of
never flown without, launch boost escape. Other redesigns would of
included elminating the APUs that used hydrazine. All those would be
great to have, and saved big bucks on processing. Eventually upgraded
TPS, going to blankets rather than individual tiles. Plus changes to
extend the shuttles life in orbit. Upgrading tires etc. Shuttle C
cargo would of been a natural outgrowth of the upgrades and a larger
more powerful flyback booster could of covered heavy lift

The costs of operation could of been cut enough to pay for the
upgrades. Plus perhaps additional new orbiters could be built slowly
over time. Keeping the design fresh. Older orbiters could of been
retired to museums as they were replaced.

The big mistake was freezing the basic design after challenger.

The shuttle could of been a safer much more capable vehicle if it
wasnt starved for cash......


NASA didn't have the tens of billions it would have required for the
"redesign" that you propose for an alternate history. Your premise is
invalid, so your alternate history is fantasy.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #3  
Old February 18th 13, 05:54 PM posted to sci.space.shuttle
Jeff Findley[_2_]
external usenet poster
 
Posts: 1,388
Default A different direction after Challenger loss

In article m,
says...

On 13-02-17 19:18, bob haller wrote:

The big mistake was freezing the basic design after challenger.


Politicians were told that Shuttle was ready for production instead of a
R&D vehicle that needed more development before production shuttles were
built.

Out of curiosity: would liquid boosters have made a difference to the
foam issue on the ET ? (aka: would the reduced vibration made foam
shedding much less of a problem) ?


Why would liquid boosters have made a difference? The ET would still
have had SOFI on the outside due to its cryogenic propellants.

In fact, the problem could have been made *worse* as it's very likely
that liquid boosters would have been LOX/kerosene, which would have
introduced even more sources for ice and/or SOFI to be shed. Of course,
you'd have to do a detailed analysis of this in order to determine the
increased risk.

The reason liquids were not chosen were due to cost and schedule
pressures. Solids have a lower development cost as well as a shorter
development period. The problems with solids include vibration during
launch, handling issues while on the ground, and their failure modes.
Specifically, case rupture is something which happens to solids with
some regularity. Case rupture is a failure mode which can happen with
very little to no warning. Add to that that such a failure includes
massive forces and spewing chunks of dense hot propellants and you've
got a failure mode that's quite possibly unsurvivable.

Jeff
--
"the perennial claim that hypersonic air-breathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced air-breathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #4  
Old February 18th 13, 06:26 PM posted to sci.space.shuttle
Greg \(Strider\) Moore
external usenet poster
 
Posts: 790
Default A different direction after Challenger loss


"Jeff Findley" wrote in message
...


Eh, I don't mind a bit of "what-if" or "alt.history" from time to time.
Comments within.


In article dcdf2f03-ac1c-4cd5-ad69-
, says...

On January 28, 1986, challenger was lost after the O ring failure.

Now lets consider a different NASA path. it became all too clear the
shuttle had no launch boost escape.


Umm, that was clear BEFORE hand. It wasn't like folks suddenly woke up one
day and said, "Oh gee, we didn't realize this."

So nasa still resumed flying but did a general shuttle redesign.

They moved away from the solids, and designed a compatible liquid
flyback booster with more power.


There are some economic and huge safety reasons for this. I have no idea
how well they'd have managed to argue this one. I suspect the politics alone
would have prevented it.


One of the uses of more power was a
jettisonable crew compartment.


Never would have happened. Huge expense. Huge additional safety concerns
(NASA rightly hate pyros, especially that many around the crew compartment.)

And would have provided limited value over a very small part of the flight
envelope.

giving the shuttle what it should of
never flown without, launch boost escape. Other redesigns would of
included elminating the APUs that used hydrazine.


This was I believe planned and cancelled, once if not twice. Certainly
would have helped with the processing flow.

All those would be
great to have, and saved big bucks on processing. Eventually upgraded
TPS, going to blankets rather than individual tiles.


Not possible. Where they could, they did this. However, for the
underside especially, you need the tiles. And you can't replace them with
monolithic pieces. Keep in mind the airframe flexes. So the tiles were far
from a terrible solution. However, there was work done on tougher tiles
that might have been of some value.

Plus changes to
extend the shuttles life in orbit. Upgrading tires etc. Shuttle C
cargo would of been a natural outgrowth of the upgrades and a larger
more powerful flyback booster could of covered heavy lift


Eh. No real need.


The costs of operation could of been cut enough to pay for the
upgrades.


"Maybe"

The problem is, NASA's not operated as a business. It's funded by a Board
of 535+1 people. They often don't look at spending that way.

Plus perhaps additional new orbiters could be built slowly
over time. Keeping the design fresh. Older orbiters could of been
retired to museums as they were replaced.


Very unlikely to happen. The flight rate just never came close to justifying
it.


The big mistake was freezing the basic design after challenger.


No. The big mistake was continuing to treat the system as an operational
design when it was clearly still an experimental system.

For example one thing the CAIB recommended was embedding recording systems
in ALL the shuttles, much like what Columbia had since it helped them
determine the cause of the accident. (R3.6-1)

Given the progress of technology, live camera feeds from the SRBs and/or
tank should have been adopted as early as possible to monitor things like
foam loss.

And overall, a very different management structure.

And changing the management structure really was the key part and basically
would have cost $0. (In reality, it wouldn't because it might mean hiring
different people, spending more money as a result of management decisions,
etc.)

Compare the history of the X-15 program (pick up Hypersonic by Jenkins) to
that of the Shuttle program. The X-15 flew more flights, but was always
considered an experimental system. Now granted, there are vast differences
in the vehicles (you could test the X-15 in an incremental fashion, you
couldn't do that with the shuttle). But also the attitudes simply were
different.

Again, I'd read the CAIB Bob. With the fixes YOU propose, we'd still have
lost Columbia.

The hardware was far from perfect, and there's good arguments for where it
could have and should have been improved.

However, the real problem was a structure that treated the system as
operational and allowed things like foam loss to continue. The original
specs required NO foam loss.

Even how foam strikes hitting the orbiter were considered changed over time
to the point where it was by STS-107 considered simply a post-landing
processing issue.

And worse, NASA wasn't even aware of some of the bipod ramp strikes until
AFTER the CAIB looked at them.

This isn't a matter where simply tossing more money at the program,
especially for the upgrades you mentioned would have made a difference.

A cultural change was what was needed.

The shuttle could of been a safer much more capable vehicle if it
wasnt starved for cash......


NASA didn't have the tens of billions it would have required for the
"redesign" that you propose for an alternate history. Your premise is
invalid, so your alternate history is fantasy.

Jeff


--
Greg D. Moore
http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #5  
Old February 18th 13, 06:28 PM posted to sci.space.shuttle
Greg \(Strider\) Moore
external usenet poster
 
Posts: 790
Default A different direction after Challenger loss

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

On 13-02-17 19:18, bob haller wrote:

The big mistake was freezing the basic design after challenger.


Politicians were told that Shuttle was ready for production instead of a
R&D vehicle that needed more development before production shuttles were
built.

Out of curiosity: would liquid boosters have made a difference to the
foam issue on the ET ? (aka: would the reduced vibration made foam
shedding much less of a problem) ?


No.





--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #6  
Old February 18th 13, 06:44 PM posted to sci.space.shuttle
Greg \(Strider\) Moore
external usenet poster
 
Posts: 790
Default A different direction after Challenger loss


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

On 13-02-18 11:54, Jeff Findley wrote:

Why would liquid boosters have made a difference? The ET would still
have had SOFI on the outside due to its cryogenic propellants.


It is my understanding that SRBs generate a hell of a lot of noise and
vibration compared to liquid fueled engines.


They do, but that most likely had little to do with the foam loss.


So I was wondering if a significant reduction of vibration would have
reduced foam shedding.



In fact, the problem could have been made *worse* as it's very likely
that liquid boosters would have been LOX/kerosene, which would have
introduced even more sources for ice and/or SOFI to be shed.


Would liquid boosters have changed the general shape of the stack ?
Longer ET to accomodate storage of more LOX, with kerosene stored in
the booster itself ? Or would each booster have been self contained and
thus likely taller ? ( a taller one exposes more of the orbiter to
potential for foam shedding).


Yes, the shape would have changed. Most likely much larger diameter as I
recall.

There was never a definitive design, but take a look at:

http://ntrs.nasa.gov/archive/nasa/ca...1998376505.pdf




--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #7  
Old February 19th 13, 09:26 AM posted to sci.space.shuttle
Brian Gaff
external usenet poster
 
Posts: 2,312
Default A different direction after Challenger loss

What ifs are great but hindsight is a wonderful thing and seldom available
as an option at the time its needed.. grin.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"bob haller" wrote in message
...
On January 28, 1986, challenger was lost after the O ring failure.

Now lets consider a different NASA path. it became all too clear the
shuttle had no launch boost escape.

So nasa still resumed flying but did a general shuttle redesign.

They moved away from the solids, and designed a compatible liquid
flyback booster with more power. One of the uses of more power was a
jettisonable crew compartment. giving the shuttle what it should of
never flown without, launch boost escape. Other redesigns would of
included elminating the APUs that used hydrazine. All those would be
great to have, and saved big bucks on processing. Eventually upgraded
TPS, going to blankets rather than individual tiles. Plus changes to
extend the shuttles life in orbit. Upgrading tires etc. Shuttle C
cargo would of been a natural outgrowth of the upgrades and a larger
more powerful flyback booster could of covered heavy lift

The costs of operation could of been cut enough to pay for the
upgrades. Plus perhaps additional new orbiters could be built slowly
over time. Keeping the design fresh. Older orbiters could of been
retired to museums as they were replaced.

The big mistake was freezing the basic design after challenger.

The shuttle could of been a safer much more capable vehicle if it
wasnt starved for cash......



  #8  
Old February 19th 13, 04:36 PM posted to sci.space.shuttle
Bob Haller
external usenet poster
 
Posts: 3,197
Default A different direction after Challenger loss

On Feb 19, 3:26*am, "Brian Gaff" wrote:
What ifs are great but hindsight is a wonderful thing and seldom available
as an option at the time its needed.. grin.

Brian

--
From the Sofa of Brian Gaff Reply address is *active"bob haller" wrote in message

....



On January 28, 1986, challenger was lost after the O ring failure.


Now lets consider a different NASA path. it became all too clear the
shuttle had no launch boost escape.


So nasa still resumed flying but did a general shuttle redesign.


They moved away from the solids, and designed a compatible liquid
flyback booster with more power. One of the uses of more power was a
jettisonable crew compartment. giving the shuttle what it should of
never flown without, launch boost escape. Other redesigns would of
included elminating the APUs that used hydrazine. All those would be
great to have, and saved big bucks on processing. Eventually upgraded
TPS, going to blankets rather than individual tiles. Plus changes to
extend the shuttles life in orbit. Upgrading tires etc. Shuttle C
cargo would of been a natural outgrowth of the upgrades and a larger
more powerful flyback booster could of covered heavy lift


The costs of operation could of been cut enough to pay for the
upgrades. Plus perhaps additional new orbiters could be built slowly
over time. Keeping the design fresh. Older orbiters could of been
retired to museums as they were replaced.


The big mistake was freezing the basic design after challenger.


The shuttle could of been a safer much more capable vehicle if it
wasnt starved for cash......


coud the liquid fly back booster have been intergrated with the ET
making it all reusable'

The tank and boosters would remain together till they got over the
indian ocean.

Or the shuttle could of flown on top of the booster and ET
  #9  
Old February 19th 13, 05:40 PM posted to sci.space.shuttle
Jeff Findley[_2_]
external usenet poster
 
Posts: 1,388
Default A different direction after Challenger loss

In article om,
says...

On 13-02-18 11:54, Jeff Findley wrote:

Why would liquid boosters have made a difference? The ET would still
have had SOFI on the outside due to its cryogenic propellants.


It is my understanding that SRBs generate a hell of a lot of noise and
vibration compared to liquid fueled engines.

So I was wondering if a significant reduction of vibration would have
reduced foam shedding.


The aerodynamic forces on the stack is one of the reasons that foam
shedding seems to be worst when the stack is going through max-Q
(maximum dynamic pressure). I doubt that reducing vibrations caused by
the boosters would have reduced foam loss by much.

Another contributor to foam loss has been defects in the foam allowing
ice or liquid air to form in the foam. In flight, these pockets of ice
or liquid will heat up and expand causing foam loss. Quality control of
SOFI application is critical because of this. I believe that over the
years, some application of SOFI was changed from hand sprayed to robotic
spraying in order to reduce defects.

In fact, the problem could have been made *worse* as it's very likely
that liquid boosters would have been LOX/kerosene, which would have
introduced even more sources for ice and/or SOFI to be shed.


Would liquid boosters have changed the general shape of the stack ?
Longer ET to accomodate storage of more LOX, with kerosene stored in
the booster itself ? Or would each booster have been self contained and
thus likely taller ? ( a taller one exposes more of the orbiter to
potential for foam shedding).


Almost certainly the outer dimensions of the boosters would have
changed, at least somewhat.

Eliminating the solids would have reduced failure modes like the one
that destroyed Challenger or the case rupture failure mode which luckily
never happened during any shuttle flight (yet has happened with the
large Titan solids and other smaller solids).

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
 




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