I'd count it as half a failure, and try to do that consistently. There was
an Ariane flight like that, I believe.
If you include the Proton Block-DM flights, of course it's no contest.
Since the beginning of 1991 there have been 119 Proton launches with 7
failures, giving 0.94 achieved success. That's inferior to the Atlas record
in the same period, but Atlas has gone through extensive hardware change in
the period (I to II to II to V). The Proton first stage has a particularly
good record, the last failure being in 1982, with 216 subsequent flights
without failure.

Murray Anderson

"Ed Kyle" wrote in message
oups.com...
Murray Anderson wrote:
Not that I disagree with your conclusion, but they probably don't
count one
of the Sea Launch failures on the grounds that the satellite made it
to the
correct orbit.
In that case they'd get 0.94 realized rate, 0.88 Bayesian, and still
lose to
Proton.

You may be right, but I think they should count
the Apstar 5 flight as a launch vehicle failure.
Otherwise, they're deluding themselves about the
true reliability of their vehicle.

According to Airclaims Ltd, the Apstar 5 flight
was a failure. [*see text below]

"www.airclaims.com/Downloads/PressReleases/SpaceLauncherYear2004.pdf"

I think most people in the industry (except for
the good folks at Boeing who wrote the press
release that started our conversation) see Proton
as the most reliable big (~5+ ton to GTO) comsat
launcher flying today. There have been 313 Proton
launches (all types) but only 52 Zenit launches
(all types, including 16 Sea Launch Zenit 3SL/DMSL
vehicles). Since 1-1-2000, there were 44 Proton
launches with one in-orbit upper stage failure.
During the same period, there were only 18 Zenit
flights with two failures (one an in-flight upper
stage failure). Compared to Proton, Zenit is a
newbie that is still being broken in. And, with the
new Briz-M storable-propellant upper stage
replacing the troublesome Energia Blok DM, Proton
reliability should improve.

During the Apstar 5 mission, the DMSL third stage
shut down 54 seconds early due to a poorly
understood electrical problem, leaving the payload
transfer orbit apogee 15,000 km low. Apstar 5 made
it to geosync on its own, but the launch vehicle
suffered a failure.

*[text from airclaims press release]

"The overall launch vehicle failure rate,
having run very low up to the end of 2004,
suddenly increased with the maiden flight
undershoot failure of the Boeing Delta IV Heavy
launch swiftly followed by the third stage
failure of a Ukrainian Tsyklon 3 rocket.
Consequently 2004 concluded as an 'averageyear'
with four launcher related failures out of 54
flights (7.4%). The other two launcher-related
failures were the SHAVIT in September which
dropped Israeli OFEQ 6 spy satellite into the
Mediterranean Sea and thepremature shutdown of
a Boeing Sea Launch ZENIT 3-SL (Sea Launch) in
June, (caused by a short in the fuel system
electronics), that almost stranded the APSTAR 5
(TELSTAR 18) commercial communications satellite."

- Ed Kyle