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Does a solid-fuel Ares 1 make sense?



 
 
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  #1  
Old September 7th 06, 09:09 AM posted to sci.space.policy
Stephen Horgan
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Posts: 66
Default Does a solid-fuel Ares 1 make sense?

Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets
should not be used for personnel because they cannot be turned off when
ignited and they have a higher failure rate than liquid fuelled
equivalents. Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.

So, does the use of the SRB for Ares make sense or not? Or are we
waiting on an accident in the future?

  #2  
Old September 7th 06, 10:16 AM posted to sci.space.policy
[email protected]
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Posts: 276
Default Does a solid-fuel Ares 1 make sense?

Stephen Horgan wrote:
Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets
should not be used for personnel because they cannot be turned off when
ignited and they have a higher failure rate than liquid fuelled
equivalents. Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.


So, does the use of the SRB for Ares make sense or not? Or are we
waiting on an accident in the future?


There are two components to this question.

I don't claim to be competent to address the technical part fully.
However, solid rockets may have improved since the days of von Braun.

As well, the Challenger catastrophe was due to a failure of the
O-rings, one that related to a specific design issue. As we know, there
were people who were *consciously aware* of a serious elevated risk of
an accident in cold weather, and who *consciously chose* not to take
steps to avoid that risk by advising NASA against a launch in cold
weather until the flaw was corrected - for _trivial_ reasons of
avoiding embarassment and protecting corporate profits.

Thus, the Challenger disaster had specific causes that don't
necessarily imply that all solid rocket boosters are inherently unsafe.
It may be now that if solid rocket boosters are used in a conscientious
and ethical manner, they may have a role in space flight.

This brings up the non-technical component. People die in industrial
accidents all the time. Being a test pilot is a hazardous occupation,
and so is being a race-car driver. At least in the days of the Apollo
program, being an astronaut was glamorous - because astronauts were
regarded as brave people, taking risks.

Therefore, some have asked - and it is not unreasonable to ask -
whether or not it is justified to spend inordinate sums to make
astronauts "safe". Are their lives worth so much more than anyone
else's?

My take on *this*, though, is that that's asking the wrong question.

For one thing, a Saturn V booster happens to be a very expensive
beastie. Making sure it doesn't blow up on the launch pad, therefore,
is going to cost a *lot* of money. Observing from statistics that we
usually spend, on average, not more than $2 million on a precaution
that saves one life, and attempting to place that as a ceiling on the
space program, would simply lead to the rockets blowing up every time,
hence no space program.

In the case of launching space probes and satellites, we can simply
weigh dollars and cents against dollars and cents. The financial losses
involved in a launch failure times the probability of a launch failure,
plus the cost of a launch given a certain level of safety
precautions... is the quantity to minimize by a wise choice of safety
precautions.

We want astronauts to effectively carry out tasks when they are in
space. This means that being an astronaut cannot be an occupation
appealing only to reckless daredevils; such people aren't suited to do
the job.

But the main issue is this:

We quite properly resist explicitly and directly putting a "dollar
figure" on human life. We expect that everything that can be done,
unless it is utterly ridiculous and absurdly excessive, and can be seen
to be so, to address any avoidable risk to human life will be done.
Anything else would leave someone *morally to blame* should an accident
occur.

The continued existence of a space program rests on the goodwill of the
American taxpayer. (Of course, that statement, although seemingly
axiomatic based on past experience, is in itself debatable. And
decisions made by private persons with respect to their own lives, and
freedom of contract and all that, would allow the existence of a
different yardstick in the event of privately-funded manned space
activities.) And that good will cannot be abused. The safety record of
the Apollo program, along with the conscientious spirit it inspired, is
the goal to emulate.

A program to send someone to Mars is *long* overdue. If we waited much
longer, particularly thanks to ideas like Bob Zubrin's, the first man
to land on Mars might well have been Chinese... or even North Korean.
(If one can take his price tag seriously, it's a pity Canada didn't
accept the offer of the Turks and Caicos Islands to join our country.
They have a nice downrange to the East, just like Florida, and they're
much closer to the Equator than any part of Canada, therefore being a
much more suitable place to launch rockets from with ecliptic-related
tasks.)

But just as there might have been worries, had the program been started
under Bill Clinton, that it was all a plot to distract us from Monica,
despite a generally magnificent response to the terrorist attack of
September 11, 2001, the administration of George W. Bush has not
managed to entirely escape controversy. (Some wag might, of course, ask
how _that_ is supposed to be a scathing criticism of _any_ U.S.
President, but I digress.)

The effort to explore space must be carefully shielded from the
corrosive winds of cynicism. Despite what some revisionist historians
may claim, John F. Kennedy was very nearly universally beloved during
his tenure as President, not just after his shocking assassination.
Today, politics seems to be played more roughly than in the halcyon
days of my youth - back then, the party of the liberals would not have
thought to get so far ahead of public opinion as to openly embrace
legalizing abortion, or, sadly, even legalizing homosexual acts between
consenting adults. Back then, instead, one could point to real
injustice suffered by black people *that was still being actively
contributed to by the actions of some governments*. And, back then, the
party of the liberals recognized that the Soviet Union was no 'workers
paradise', but a cruel hoax played on those who looked for a better way
than the injustices and union-busting of the Depression.

In other words, since then, the Democrats have steadily been losing
respectability, and the Republicans have been gaining it - but we are
left without a political party with which we can be *fully satisfied*.
One that isn't led by people who will let political correctness get
ahead of national security - but that is led by people we can trust to
have their hearts in the right place.

If the American people could have a President they could *love*, then
were he to suggest bold new initiatives in space, all thoughts of a
base partisan motive would be banished, and we could proceed on this
bold adventure with our hearts properly singing.

John Savard

  #3  
Old September 7th 06, 03:56 PM posted to sci.space.policy
Thomas Lee Elifritz
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Posts: 403
Default Does a solid-fuel Ares 1 make sense?

Stephen Horgan wrote:

So, does the use of the SRB for Ares make sense or not?


No.

Or are we waiting on an accident in the future?


Yes.

It's a perfect example of a rocket on steroids, huge bulging head,
skinny legs. Just the impression we need to give to the world.

America - high on steroids, totally irrational.

http://cosmic.lifeform.org
  #4  
Old September 7th 06, 11:14 PM posted to sci.space.policy
Brian Thorn
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Posts: 510
Default Does a solid-fuel Ares 1 make sense?

On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan"
wrote:

Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.


And part of the liquid propulsion system (the External Tank) caused
the Columbia accident. Call it a wash.

So, does the use of the SRB for Ares make sense or not?


Off the shelf, 4 segment SRB possibly, if only minimal changes are
necessary. The 5-segment booster now planned makes no sense
whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped
to 5-segments and dumped the SSME, NASA should have cut its losses and
switched to one of the EELVs.

Brian

  #5  
Old September 8th 06, 03:25 AM posted to sci.space.policy
Jorge R. Frank
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Posts: 2,089
Default Does a solid-fuel Ares 1 make sense?

Brian Thorn wrote in
:

On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan"
wrote:

Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.


And part of the liquid propulsion system (the External Tank) caused
the Columbia accident. Call it a wash.

So, does the use of the SRB for Ares make sense or not?


Off the shelf, 4 segment SRB possibly, if only minimal changes are
necessary. The 5-segment booster now planned makes no sense
whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped
to 5-segments and dumped the SSME, NASA should have cut its losses and
switched to one of the EELVs.


Hmm? Ares 5 was always 5-segment. Did you mean Ares 1?


--
JRF

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check "Organization" (I am not assimilated) and
think one step ahead of IBM.
  #6  
Old September 8th 06, 03:35 AM posted to sci.space.policy
Craig Fink
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Posts: 1,858
Default Does a solid-fuel Ares 1 make sense?

On Thu, 07 Sep 2006 01:09:51 -0700, Stephen Horgan wrote:

Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets
should not be used for personnel because they cannot be turned off when
ignited and they have a higher failure rate than liquid fuelled
equivalents. Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.

So, does the use of the SRB for Ares make sense or not? Or are we
waiting on an accident in the future?


Solid rockets on manned vehicles only make sense if you like holding your
breath for two minutes.

--
Craig Fink
Courtesy E-Mail Welcome @
  #7  
Old September 8th 06, 12:45 PM posted to sci.space.policy
Jeff Findley
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Posts: 5,012
Default Does a solid-fuel Ares 1 make sense?


"Stephen Horgan" wrote in message
ups.com...
Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets
should not be used for personnel because they cannot be turned off when
ignited and they have a higher failure rate than liquid fuelled
equivalents. Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.


Actually, you can install thurst termination systems on the SRB. The ones
installed on the shuttle unzipper the casing along the length.
Unfortunately this event would be extremely violent. So some here do say
that you can "turn off" the thrust of a large SRB, but I have no idea if the
CEV designers will design the CEV such that it could survive thrust
termination. The obvious way to do this would be to first fire the escape
tower, and then the thurst termination system.

Unfortunately, the Titan program showed us that there are failure modes of
large, segmented boosters that give little to no warning before the things
violently destroy themselves, so the above wouldn't necessarily help in all
cases.

So, does the use of the SRB for Ares make sense or not? Or are we
waiting on an accident in the future?


Possibly. Of greater significance is the fact that it will be a 5-segment
SRB instead of the 4-segment shuttle SRB that we have a lot of experience
with. Adding that fifth segment (with it's new fuel cross section and
thrust versus time curve) essentially makes it a new SRB.

Also, Aries I requires a roll control package for the SRB, and an all new
upper stage which uses an engine that while based on the venerable J-2 used
on the Saturns, was never fully developed. In other words, we have zero
flight experience with the upper stage and its engine.

Put all this together and the "safe, simple, soon" claims of ATK are clearly
marketing intended to hide the fact that this design has serious "image
problems" when it comes to safety, complexity (with its 5th segment and
upper stage this thing is a bit too long and slender which could cause
design challenges), and schedules.

Then there is the whole philosophy of keeping as much shuttle infrastructure
around as possible for Aries V. This added overhead won't make Aries I
inexpensive at the low flight rates expected.

EELV's are looking better to me every day.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)


  #8  
Old September 8th 06, 02:03 PM posted to sci.space.policy
Jeff Findley
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Posts: 5,012
Default Does a solid-fuel Ares 1 make sense?


"Brian Thorn" wrote in message
...
On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan"
wrote:

Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.


And part of the liquid propulsion system (the External Tank) caused
the Columbia accident. Call it a wash.


True, but that one is easy to avoid. Stick your sensitive payloads above
the tanks with SOFI, just like Saturn V and the proposed Aries designs.

So, does the use of the SRB for Ares make sense or not?


Off the shelf, 4 segment SRB possibly, if only minimal changes are
necessary.


New roll control package, redesign of the top of the SRB to support payloads
on the top rather than the side, elimination of the SRB separation motors,
etc.

The 5-segment booster now planned makes no sense
whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped
to 5-segments and dumped the SSME, NASA should have cut its losses and
switched to one of the EELVs.


Agreed. Also, while the planned J-2X is based off the venerable J-2, and
follow-on development done previously, it's not a flight proven engine. I
would have felt better if NASA had picked an engine being flown today, not
one where they pretty much have to scour storage facilities and museums for
hardware to examine. :-P


But all of that is beside the point. Aries I/V are designed to keep the
shuttle infrastructure intact. As such, it's going to be yet another NASA
only, high fixed cost, low flight rate vehicle that has little to no chance
of being economical and little to no chance of anyone outside of NASA ever
using it. That's not a recipe that will help the US launch industry in any
way, shape, or form.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)


  #9  
Old September 8th 06, 02:06 PM posted to sci.space.policy
Jeff Findley
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Posts: 5,012
Default Does a solid-fuel Ares 1 make sense?


"Craig Fink" wrote in message
news
On Thu, 07 Sep 2006 01:09:51 -0700, Stephen Horgan wrote:

Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets
should not be used for personnel because they cannot be turned off when
ignited and they have a higher failure rate than liquid fuelled
equivalents. Of course the SRB has only failed once in STS operation,
but that was enough to cause the Challenger catastrophe.

So, does the use of the SRB for Ares make sense or not? Or are we
waiting on an accident in the future?


Solid rockets on manned vehicles only make sense if you like holding your
breath for two minutes.


Yep. As the Titan showed, they can fail extremely quickly and
destructively. Not exactly a case I'd want to face if I was trying to
design a launch escape system for the CEV. I wouldn't exactly want to trust
a multi billion dollar lunar lander and TLI stage to two 5-segment versions
of them. There is zero flight experience with 5 segment SRB's.

If they were so "safe, simple, and soon", you'd think we would have seen
them developed instead of the current Al-Li ET to increase payloads for ISS
missions.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)


  #10  
Old September 8th 06, 06:37 PM posted to sci.space.policy
Brian Thorn
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Posts: 510
Default Does a solid-fuel Ares 1 make sense?

On Thu, 07 Sep 2006 21:25:33 -0500, "Jorge R. Frank"
wrote:


Off the shelf, 4 segment SRB possibly, if only minimal changes are
necessary. The 5-segment booster now planned makes no sense
whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped
to 5-segments and dumped the SSME, NASA should have cut its losses and
switched to one of the EELVs.


Hmm? Ares 5 was always 5-segment. Did you mean Ares 1?


Whoops! Yes.

Brian
 




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