non man rated booster compared to shuttle?

I ask this. Which is safer?

a shuttle

or a man rated capsule like apollo on a non man rated booster like a delta?

It would be interesting to take a historical look at a booster, and the failure
rate that would kill a crew if the capsule had launch boost escape...

now compare that with the known historical failure of the shuttles...

which would be safer???
HAVE A GREAT DAY!

(bob haller) wrote:

I ask this. Which is safer?

a shuttle

or a man rated capsule like apollo on a non man rated booster like a delta?

Probably pretty much about the same.

It would be interesting to take a historical look at a booster, and the failure
rate that would kill a crew if the capsule had launch boost escape...

It would be interesting to learn what drugs erased the knowledge that
launch failures are only portion of the total risks from what passes
for your mind.

D.
--
Touch-twice life. Eat. Drink. Laugh.

It would be interesting to learn what drugs erased the knowledge that
launch failures are only portion of the total risks from what passes
for your mind.

D.
--
Touch-twice life. Eat. Drink. Laugh.







Well there are two stages of flight. first launch and achieve orbit, which is
the boosters job...

then theres in orbit operations which dont include the now discarded boosters.

my questions is what perentages of boosters fail where launch boost escape
wouldnt work?
HAVE A GREAT DAY!

On Sat, 14 Aug 2004 16:31:59 GMT, (Derek Lyons)
wrote:

It would be interesting to learn what drugs erased the knowledge that
launch failures are only portion of the total risks from what passes
for your mind.

....Probably dropping battery acid and snorting diet coke.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

bob haller a écrit dans le message :
...
I ask this. Which is safer?

a shuttle

or a man rated capsule like apollo on a non man rated booster like a
delta?


Well, remember. Ariane V is/was supposed to be man-rated ( to launch
Hermes ). Given the current record, would you volunteer to take a seat?

bob haller a écrit dans le message :
...
I ask this. Which is safer?

a shuttle

or a man rated capsule like apollo on
a non man rated booster like a delta?

"HAESSIG Frédéric Pierre Tamatoa" wrote in message ...
Well, remember. Ariane V is/was supposed to be man-rated ( to launch
Hermes ). Given the current record, would you volunteer to take a seat?

Yes, the Ariane 5 was also supposed to use man-rated solid fuel
boosters. The same goes to an uprated Saturn 5 that was supposed to
use solid fuel boosters.

Anyway. Riding the current version of the Space Transportation System
is equivalent to have you launched by a firecracker, because that is
what a solid fuel booster is, an oversized firecracker.

EAC a écrit dans le message :
...

"HAESSIG Frédéric Pierre Tamatoa" wrote in message
...
Well, remember. Ariane V is/was supposed to be man-rated ( to launch
Hermes ). Given the current record, would you volunteer to take a seat?

Yes, the Ariane 5 was also supposed to use man-rated solid fuel
boosters. The same goes to an uprated Saturn 5 that was supposed to
use solid fuel boosters.


Actually, it never was the solid fuel boosters which caused the problems on
Ariane V. This has always worked flawlessly, AFAIK. IIRC, in the first case,
the destruction was commanded from ground ( which, in case of manned flight
would be avoided until the crew bailed out ). In the second case, it was a
flaw in the Vulcain II nozzle design. I wonder if the ejection system could
have worked in the second case ( or if Hermes could have landed by itself ).
Anyhow, these were qualification flights, so I doubt there would have been a
crew, even if Hermes had been ready by that time. I seem to remember it was
to be readied a bit later than Ariane V maiden flight, but with all the
delays everywhere, it may have caught up.

In article ,
"HAESSIG Frédéric Pierre Tamatoa" writes:

EAC a écrit dans le message :
...

"HAESSIG Frédéric Pierre Tamatoa" wrote in message
...
Well, remember. Ariane V is/was supposed to be man-rated ( to launch
Hermes ). Given the current record, would you volunteer to take a seat?

Yes, the Ariane 5 was also supposed to use man-rated solid fuel
boosters. The same goes to an uprated Saturn 5 that was supposed to
use solid fuel boosters.


Actually, it never was the solid fuel boosters which caused the problems on
Ariane V. This has always worked flawlessly, AFAIK. IIRC, in the first case,
the destruction was commanded from ground ( which, in case of manned flight
would be avoided until the crew bailed out ). In the second case, it was a
flaw in the Vulcain II nozzle design. I wonder if the ejection system could
have worked in the second case ( or if Hermes could have landed by itself ).
Anyhow, these were qualification flights, so I doubt there would have been a
crew, even if Hermes had been ready by that time. I seem to remember it was
to be readied a bit later than Ariane V maiden flight, but with all the
delays everywhere, it may have caught up.

The first Ariane V flight was an interesting example of foolish
complacency on the part of the entire team, from managers down through
techs. The reason for the loss of guidance was that they re-used the
Ariane IV guidance system. Not a bad idea, but the greater
acceleration of the Ariane V caused it to overflow several data
accumulators. This caused the guidance logic to drop into a debug mode
where it sat & waited for somebody to look at its core dump.

This showed an incredible lack of attention on two fronts - The buffer
overruns would have been immediately obvious if there had been even
the most minimal amount of realistic testing performed. Even a simple
black-box simulation would have shown it. Even with that, it would
have been possible for th eguidance system to control the rocket,
albeit not as accurately, if it had kept functioning. Having the
system drop into a mode where it was not functioning, and was waiting
for an irrelevant service was foolish. The system should have been
set up to operate in a degraded, or even pregressively failing mode.
Failure, especially in a complex system like a space booster and its
guidance system, isn't an option - it's bundled with the system. Once
it leaves the ground, the question isn't "Will it fail?", but "What
happens when it _does_ fail?". It brings up the question of how,
other than just by saying so, or claiming it was designed that way,
they expected to man-rate Airane V.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

Peter Stickney a écrit dans le message :
l...


The first Ariane V flight was an interesting example of foolish
complacency on the part of the entire team, from managers down through
techs.

Not so much at tech or engineer level, IMHO, but definitely at management
level. As well as a willingness not to listen to those pesky tech-types, who
always want more useless testing anyway ( yes, I was once told that, nearly
word for word ). When a manager tells you ' So we don't need
tests/repair/replacement because I don't see what can go wrong. ' and your
immediate reaction is 'Well, I see at least a dozen potential failure
without even trying'. You're in trouble. Sorry, you just hit one of my
buttons and I had some ...troublesome relation with management in the last
two jobs I took ( somehow they don't seem to like me that much. I wonder
why? Especially when I tell them my opinion about their schedule-inspired
decisions )

The reason for the loss of guidance was that they re-used the
Ariane IV guidance system. Not a bad idea, but the greater
acceleration of the Ariane V caused it to overflow several data
accumulators. This caused the guidance logic to drop into a debug mode
where it sat & waited for somebody to look at its core dump.

Exactly.

'We don't need to retest anything. This was flight proven. What? different
conditions? don't bothe rme with details. I have a vision.'


This showed an incredible lack of attention on two fronts - The buffer
overruns would have been immediately obvious if there had been even
the most minimal amount of realistic testing performed. Even a simple
black-box simulation would have shown it.

Definitely.

The one of the three worst case of cheese-paring by cutting testing I can
think of right away ( the other two being hubbel and that Mars satelite
which was lost because of a metric/imperial unit problem - can someone
remind me of the name, please - ).

Even with that, it would
have been possible for th eguidance system to control the rocket,
albeit not as accurately, if it had kept functioning. Having the
system drop into a mode where it was not functioning, and was waiting
for an irrelevant service was foolish. The system should have been
set up to operate in a degraded, or even pregressively failing mode.
Failure, especially in a complex system like a space booster and its
guidance system, isn't an option - it's bundled with the system. Once
it leaves the ground, the question isn't "Will it fail?", but "What
happens when it _does_ fail?". It brings up the question of how,
other than just by saying so, or claiming it was designed that way,
they expected to man-rate Airane V.


Multiple redundancy. Triple for most systems, except for the flight
computer, which runs in dual mode with hot redundancy. The problem was, as
they had the same SW, and the problem was in the SW, the failure occured
exactly the same way in both.

On every man-rated models, there are catastrophic potential events
catastrophic being classified as loss of lives in this case ). The goal is
to have them never occur upon a single ( or two separate, for ATV ) failure
or error. Here was a single failure which led to the simultaneous failure of
both of the redundant systems. A single point of failure. A BIG no-no in
design. Obviously this was a big failure in the design and analysis.

In article ,
Peter Stickney wrote:
The first Ariane V flight was an interesting example of foolish
complacency on the part of the entire team, from managers down through
techs. The reason for the loss of guidance was that they re-used the
Ariane IV guidance system. Not a bad idea, but the greater
acceleration of the Ariane V caused it to overflow several data
accumulators...

Close, but not quite right. There were several interlocking mistakes:

1. The problematic routine in the inertial measurement unit software was
used to restart Ariane 4 countdowns after late holds. It had no role
whatsoever on Ariane 5, but it was left in.

2. Said routine also had no reason to be left running after launch, yet it
was (on both Ariane 4 and Ariane 5).

3. Most float-to-integer conversions in the software were protected
against overflow, but to reduce overhead, a few that "couldn't overflow"
weren't. One, in this particular routine, overflowed because of the
higher acceleration of Ariane 5, and this caused an exception trap. As
Les Hatton put it: "Approximately 37 seconds into the flight, the 16-bit
integer overflowed. Now in a sloppier language like C, the program would
have continued happily rumbling away to itself but would not in all
probability have interfered with the flight. However, the Ada language is
made of sterner stuff. Faced with this run-time error, the program threw
an exception..."

4. Any unexpected exception was considered a sign of a hardware failure.
Upper management basically thought they could prevent design errors by
ordering the engineers not to make any. So any problem was a random
hardware failure, in which case it seemed reasonable for that inertial
unit to stop dead and let the other one carry on. But since there was a
common design flaw, they *both* did that in fast succession.

This caused the guidance logic to drop into a debug mode
where it sat & waited for somebody to look at its core dump.

No, actually it was worse -- the inertial unit started spewing debug
output down the line to the main guidance system, which interpreted it as
guidance updates! This would qualify as mistake #5, except that it made
no difference in the end: with both inertial units in debug mode, the
rocket was doomed even if they'd just gone silent.

This showed an incredible lack of attention on two fronts - The buffer
overruns would have been immediately obvious if there had been even
the most minimal amount of realistic testing performed.

There *was* considerable testing... of the new stuff.

And *that* was mistake #5: full guidance simulations were dropped from
the test plans as unnecessary when budgets and schedules started to pinch.
The software for the central guidance computer was tested, but full-system
tests including the inertial units (or at least their software) were
thought less important -- after all, those units and that code had flown
many times on Ariane 4.

...Even with that, it would
have been possible for th eguidance system to control the rocket,
albeit not as accurately, if it had kept functioning.

As per above, there would have been no accuracy loss at all -- the problem
was in a routine which wasn't involved in actually guiding the rocket.
Had the inertial-unit software done its best to carry on despite problems,
all would have been well.

But the attitude that the design would be perfect, and so only random
hardware failures would cause trouble, was everywhere in that program.

...It brings up the question of how,
other than just by saying so, or claiming it was designed that way,
they expected to man-rate Airane V.

Man-rating is an essentially meaningless process anyway. (In practice,
man-rated launchers do not appear to have higher reliability than
non-man-rated ones.)
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |