Python from Wise Guy's Viewpoint

[Andrew Dalke]

Joachim Durchholz
> Not quite - that was a loss of 500 million dollars. I don't know what
> the software development costs were, so I'm just guessing here, but I
> think it's relatively safe to assume a doubly redundant system would
> already have paid off if it had caught the problem.

Since the Mars rover mission a few years ago cost only about $250million,
I'm going to assume that you included payload cost.  Here's some
relevant references I found [after sig], which suggests a price per rocket
of well under $100 million and the cost of the "four uninsured scientific
satellites" made it be about $500 million.

It used to be that rockets needed a lot of real-world tests before
people would stick expensive payloads on them.  For a while, dead
weight was used, but people like amateur hams got permission to
put "cheap" satellites in its place, and as the reliability increased,
more and more people were willing to take chances with unproven
rockets.

So there's an interesting tradeoff here between time spent on live
testing and the chance it will blow up.  Suppose Ariane decided
to launch with just bricks as a payload.  Then they would have
been out ~$75 million.  But suppose they could convince someone
to take a 10% chance of failure to launch a $100 million satellite
for half price, at $40 million.  Statistically speaking, that's a good
deal.  As long as it really is a 10% chance.

(The satellites were uninsured, which suggests that this was
indeed the case.)

However, it seems that 4 of the first 14 missions failed, making
about a 30% failure rate.  It also doesn't appear that all of those
were caused by software failures; the 4th was in a "cooling
circuit."

> The point is that no amount of software technology would have caught the
> problem if the specifications are wrong.

I agree.

                    Andrew
                    dalke at dalkescientific.com


http://www.namibian.com.na/2002/june/techtalk/02651A180A.html
] The Ariane 44L rocket equipped with four liquid strap-on boosters --
] the most powerful in the Ariane-4 series --
 ...
] Specialists estimated the cost of the satellite, launch and insurance at
] more than $250 million.


http://www.cnn.com/2000/TECH/space/12/20/rocket.ariane.reut/
] Western Europe's new generation Ariane-5 rocket has placed three
] satellites into space
 ...
] Experts have estimated the cost of the [ASTRA 2D] satellite,
] launch and insurance at over $85 million
  ...
] The estimated cost of the GE-8 satellite, launch and insurance is
] over $125 million.

] But Ariane-5's career began with a spectacular failure during its
] maiden test launch in June 1996, exploding 37 seconds after
] lift-off and sending four uninsured scientific satellites worth $500
] million plunging into mangrove swamps on French Guiana's coast.

http://www.centennialofflight.gov/essay/SPACEFLIGHT/ariane/SP42.htm
] After Arianespace engineers rewrote the rocket's control software,
] the second Ariane-5 launch successfully took place on October 30,
] 1997. More launches followed and the rocket soon entered full commercial
] service, although it suffered another failure on its tenth launch in July
2001.
] Ariane-5 joined the Russian Proton, American Titan IV and Japanese
] H-IIA as the most powerful rockets in service. Ariane-5 initially had a
very
] high vehicle cost, but Arianespace mounted an aggressive campaign to
] significantly reduce this cost and make the rocket more cost-effective.
The
] company also planned further upgrades to the Ariane-5 to enable it to
remain
] competitive against a growing number of competitors.

http://www.chron.com/cgi-bin/auth/story.mpl/content/interactive/space/news/9
9/990824.html
] Each launch of Japan's flagship H-2 rocket to place a satellite into
] geostationary orbit costs close to 19 billion yen, about double the cost
] of competitors such as the European Space Agency's Ariane rocket.
(19 billion yen ~ $190 million => ~$100million for geostationary orbit on
Ariane)

] Part of the six-billion European-Currency-Unit ($6.28 billion U.S.) cost
of
] the Ariane 5 project went toward construction of new facilities at ESA's
Kourou,
] French Guiana launch complex

http://www.rte.ie/news/2002/1212/satellite.html
] It is the fourth failure of an Ariane-5 in its 14-mission history, and is
] being seen as a major setback for the European space programme.
See also
http://www.dw-world.de/english/0,3367,1446_A_713425,00.html
] the problem occurred in the cooling circuit of one of the rocket's main
] engines. A change in engine speed around 180 seconds after take-off
] caused the launcher to "demonstrate erratic behaviour".