Launch Failure Review for 2006

As of August 15, 2006, there had been four space launch failures in 36
world-wide attempts during the year, including two since the beginning
of July. I've posted a summary of reported probable causes for all of
these failures at:

"http://www.geocities.com/launchreport/blog015.html"

- Ed Kyle

On 15 Aug 2006 11:19:38 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

As of August 15, 2006, there had been four space launch failures in 36
world-wide attempts during the year, including two since the beginning
of July. I've posted a summary of reported probable causes for all of
these failures at:

"http://www.geocities.com/launchreport/blog015.html"

So the industry is running under 90% success for the year so far.

Rand Simberg wrote:
On 15 Aug 2006 11:19:38 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

As of August 15, 2006, there had been four space launch failures in 36
world-wide attempts during the year, including two since the beginning
of July. I've posted a summary of reported probable causes for all of
these failures at:

"http://www.geocities.com/launchreport/blog015.html"

So the industry is running under 90% success for the year so far.

Yes, but it still might be a short-term aberration.
Since 2000, inclusive, the success rate has been about
94%. There have been 3 or 4 failures each year and
an average of 63.5 launches. 2006 can still make the
norm if no more failures occur - but that probably won't
happen if Mr. Musk fires up another Falcon!

- Ed Kyle

On 15 Aug 2006 11:52:16 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

So the industry is running under 90% success for the year so far.

Yes, but it still might be a short-term aberration.
Since 2000, inclusive, the success rate has been about
94%. There have been 3 or 4 failures each year and
an average of 63.5 launches. 2006 can still make the
norm if no more failures occur - but that probably won't
happen if Mr. Musk fires up another Falcon!

I'm not sure what your (pessimistic) assessment of Falcon reliability
is based on.

Rand Simberg wrote:
On 15 Aug 2006 11:52:16 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

So the industry is running under 90% success for the year so far.

Yes, but it still might be a short-term aberration.
Since 2000, inclusive, the success rate has been about
94%. There have been 3 or 4 failures each year and
an average of 63.5 launches. 2006 can still make the
norm if no more failures occur - but that probably won't
happen if Mr. Musk fires up another Falcon!

I'm not sure what your (pessimistic) assessment of Falcon reliability
is based on.

Two things. History and results.

Historically, brand new launch vehicles suffer an above-average
failure rate during their first flights. Based on historical results,
a good guess of the odds for an inaugural launch is 50-50.
That was my guess for Falcon.

Results-wise the first Falcon failed, which leads to a Bayesian
guess at the chances for the next launch succeeding of only
1 in 3. This is a guess, but it has a basis in history and
results.

Other than that, I also got a "feeling" when I followed the
initial trouble-ridden launch campaign, which spanned nearly
five months, but only managed to damage or destroy *two*
complete launch vehicles!

- Ed Kyle

On 15 Aug 2006 13:15:58 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

I'm not sure what your (pessimistic) assessment of Falcon reliability
is based on.

Two things. History and results.

Historically, brand new launch vehicles suffer an above-average
failure rate during their first flights. Based on historical results,
a good guess of the odds for an inaugural launch is 50-50.
That was my guess for Falcon.

Results-wise the first Falcon failed, which leads to a Bayesian
guess at the chances for the next launch succeeding of only
1 in 3. This is a guess, but it has a basis in history and
results.

And the reason for the odds of a second launch being successful being
less than those for a first launch are...?

Rand Simberg wrote:
On 15 Aug 2006 13:15:58 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

I'm not sure what your (pessimistic) assessment of Falcon reliability
is based on.

Two things. History and results.

Historically, brand new launch vehicles suffer an above-average
failure rate during their first flights. Based on historical results,
a good guess of the odds for an inaugural launch is 50-50.
That was my guess for Falcon.

Results-wise the first Falcon failed, which leads to a Bayesian
guess at the chances for the next launch succeeding of only
1 in 3. This is a guess, but it has a basis in history and
results.

And the reason for the odds of a second launch being successful being
less than those for a first launch are...?

The result of the first launch has an effect on the
guess (hypothesis) for the next launch success
probability. Since the first result (the evidence) was
a failure, the next guess mathematically has to be
lower than the previous guess. The guess can vary
quite a bit during the first few launches, but the low
value can be thought of as representing the
low-confidence of the initial guesses. (i.e., based on
the results and history, I can only say that I'm "pretty
sure" that this next Falcon has at least a 1 in 3 chance
of succeeding.)

The initial guesses could certainly be wrong, but the
guesses will be adjusted and will thus approach "truth"
as more flights occur. SpaceX Falcon would quickly
join the ranks of many of the world's standard launch
vehicles with only a half-dozen consecutive successes.

- Ed Kyle

In article .com,
"Ed Kyle" wrote:

2006 can still make the
norm if no more failures occur - but that probably won't
happen if Mr. Musk fires up another Falcon!

What, no faith that the problems have been fixed?

- Joe

Joe Strout wrote:
In article .com,
"Ed Kyle" wrote:

2006 can still make the
norm if no more failures occur - but that probably won't
happen if Mr. Musk fires up another Falcon!

What, no faith that the problems have been fixed?

- Joe

Even if they have, there may be other undiscovered problems
still out there in the unflown flight envelope. As for that
"B-nut" thing, I think that DARPA/SpaceX have only been
able to determine the "most likely" failure cause.

Faith? Fly me a few successes. Then I'll start to "believe"!

- Ed Kyle

On 15 Aug 2006 15:02:17 -0700, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

What, no faith that the problems have been fixed?

- Joe

Even if they have, there may be other undiscovered problems
still out there in the unflown flight envelope. As for that
"B-nut" thing, I think that DARPA/SpaceX have only been
able to determine the "most likely" failure cause.

Faith? Fly me a few successes. Then I'll start to "believe"!

I'm not asking for faith. I'm asking for an explanation why the first
launch has a one in two chance of success, while the second launch has
a one in three...