Proton Only $48.7 Million

Brian Thorn wrote in message . ..
On 8 Sep 2003 05:22:44 -0700, (Gunter Krebs)
wrote:

E - the russian launchers are reliable.

Tell that to Express A1, Astra 1K, or Mars '96 people.


Compared with comparable launchers ( 4 tons to GTO),
Proton was near the top of the reliability list for
the 1990-2002 period. It is especially interesting
to compare $49 million Proton with the $300-$500
million Titan IV record. Both rockets are capable
of putting satellites directly into geosync orbits -
a more complex effort than the Ariane/Zenit/Long March
GTO missions. Remember too that during the 1990s,
Proton was flying while its country's infrastructure
collapsed around it.

-----------------------------------------------
Vehicle Successes/Attempts Bayesian
Predicted
Reliability
-----------------------------------------------
Ariane 4 106/109 0.97
Proton 108/116 0.92
Titan IV 29/33 0.86
Ariane 5 10/14 0.69
Zenit 2/3 24/29 0.81
H-II(A) 9/11 0.77
CZ-3B 4/5 0.71
-----------------------------------------------

- Ed Kyle

ed kyle a écrit dans le message :
...
Brian Thorn wrote in message
. ..
On 8 Sep 2003 05:22:44 -0700, (Gunter Krebs)
wrote:

E - the russian launchers are reliable.

Tell that to Express A1, Astra 1K, or Mars '96 people.


Compared with comparable launchers ( 4 tons to GTO),
Proton was near the top of the reliability list for
the 1990-2002 period. It is especially interesting
to compare $49 million Proton with the $300-$500
million Titan IV record. Both rockets are capable
of putting satellites directly into geosync orbits -
a more complex effort than the Ariane/Zenit/Long March
GTO missions. Remember too that during the 1990s,
Proton was flying while its country's infrastructure
collapsed around it.

-----------------------------------------------
Vehicle Successes/Attempts Bayesian
Predicted
Reliability
-----------------------------------------------
Ariane 4 106/109 0.97
Proton 108/116 0.92
Titan IV 29/33 0.86
Ariane 5 10/14 0.69

Disagree on that one. Ariane 5 failed 3 times ( 2.5, if you want to be
pedantic; Artemis was saved ), not 4, which make it 11/14 or 0.79. Still not
great, especially as it was supposed to be man-rated, and the quoted
reliability figure was 0.995....
( I suppose you were considering 502 a failure, which I don't ).



Zenit 2/3 24/29 0.81
H-II(A) 9/11 0.77
CZ-3B 4/5 0.71
-----------------------------------------------

- Ed Kyle

"HAESSIG Frédéric Pierre Tamatoa" wrote in message ...
ed kyle a écrit dans le message :
...

-----------------------------------------------
Vehicle Successes/Attempts Bayesian
Predicted
Reliability
-----------------------------------------------
Ariane 4 106/109 0.97
Proton 108/116 0.92
Titan IV 29/33 0.86
Ariane 5 10/14 0.69

Disagree on that one. Ariane 5 failed 3 times ( 2.5, if you want to be
pedantic; Artemis was saved ), not 4, which make it 11/14 or 0.79. Still not
great, especially as it was supposed to be man-rated, and the quoted
reliability figure was 0.995....
( I suppose you were considering 502 a failure, which I don't ).


Yep. I've never liked the "partial success" concept - especially
when it came to space launch reliability records. I use the same
cold definition that the launch insurance underwriters use. Either
the launcher put the payload where it was supposed to go (within
a predetermined limit), or it didn't. If it did, it succeeded.
If it didn't, it failed. I consider Saturn 502 a failure, for
example.

Ariane 502 developed a roll torque created by the core stage
Vulcain engine that caused the vehicle to spin up to 5.5 rmp.
This pushed propellant away from the feed sump, causing the
engine to shut down 10-20 seconds early. The second stage
attempted to compensate, but the qualification payloads were
still left about 9000 km short of their target GTO apogee.

Ariane 510 was even worse. Its second stage shut down 80
seconds early, stranding Artemis and BSat-2b about 18,000 km
short of the target GTO apogee. It doesn't matter that Artemis
was saved. That was a happy result in a of itself, but it
doesn't change the fact that the launcher failed. In addition,
BSat-2b was not saved.

Ariane 5 has had its troubles, but I think it will turn out to
be more reliable than Proton in the long run.

- Ed Kyle

It's discouraging to look at the analyses up this thread. There is
however, something odd here. Namely, why don't we see similar
nitty-gritty analyses of cost and return from our military and
armaments industries?

Cheers -- Martha Adams