The Risks Digest

The RISKS Digest

Forum on Risks to the Public in Computers and Related Systems

ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

Volume 1 Issue 42

Tuesday, 28 Jan 1986


oThe Space Shuttle Challenger
Peter G. Neumann
o When you start an engine at 40 below, you could be injured...
David Wade
o "Brazil" and Risks to the Public
Martin Minow

The Space Shuttle Challenger

Peter G. Neumann <Neumann@SRI-CSL.ARPA>
Tue 28 Jan 86 09:45:12-PST

For those of you who haven't heard, the Challenger blew up this morning, 1
minute and 12 seconds after launch, during maximum thrust.  Everything
appeared to be working properly.  TV pictures show one of the solid rocket
boosters on the side going first, then everything.  (There had been some
concern because the temperature went below 28 degrees Fahrenheit during the
night at Canaveral, and that temperature is considered critical because of
ice formation.)  The Challenger had consistently been the most reliable of
all the shuttles.

One unvoiced concern from the RISKS point of view is the presence on each
shuttle of a semi-automatic self-destruct mechanism.  Hopefully that
mechanism cannot be accidentally triggered.

When you start an engine at 40 below, you could be injured...

David Wade <djw%f@LANL.ARPA >
Tue, 21 Jan 86 10:42:37 mst
I did not intentionally deceive you or overdramatize the risks taken during
checkout of "my" Fusion experiments.  ( I say "my" because I'm proud of them
and they are the only ones I've ever worked on. ) 

People were normally behind blast walls during operation.  However, certain
individuals became familiar enough with the "normal" operation of the machine
( and, at times, frustrated with certain types of idiosyncratic behavior )
did put themselves at risk in order to trace down short circuits.

People became convinced ( with time ) that the software was reliable.  Note
that routine operation after "checkout" was complete was a lot different
than operation during "checkout".

We normally operated behind blast walls with 2-3 video cameras ( and finally
got a vcr ).  One video camera was hung where it could "see" most of the power
supplies.  That camera had a zoom lense and it was routed through a "frame
grabber" which was triggered off the master trigger.  Many times that camera
would "bloom" with the most dramatic evidence of a direct short.

Visitors see the remains of the capacitor which exploded years ago on the CTX
experiment.  The safety record is excellent, but it could be ruined at any
time by stupidity.

None of the articles I've seen have criticised the SDI on the basis of the
stupidity of the operators, so I wasn't "flaming" that point.  I personally
believe that the stupidity is evidenced by the lack of a world concensus
for exploration of space and demilitarization of the world situation.

Perhaps this is just "liberal crap" left over from my youth in the 60's;
perhaps I should re-examine my beliefs,  but I think back on my life as an
"Air Force Brat" whose father was in SAC ( the Strategic Air Command ) in the
50's, and I remember "the bay of pigs" week.  That's probably one of the
closest "near-death" experiences you've ever had,  aren't you thankful that
you made it?  How did you feel?  Did it hurt?  Did you feel any different
when you packed your sleeping bag and your tent in the station wagon and left
for the mountains with the rest of the kids and moms that you knew?  Do you
think that people have that same feeling now when they discuss survivability?

I think that SDI has given the flower children their first hope since 1957.
If it does only that, it has helped the world by forcing negotiations.

"Brazil" and Risks to the Public

Martin Minow, DECtalk Engineering ML3-1/U47 223-9922 <minow%rex.DEC@decwrl.DEC.COM >
Monday, 20 Jan 1986 05:43:12-PST
Readers of the RISKS Forum might enjoy seeing the new movie, Brazil,
which has been described as 1984 redone by Monty Python.

Martin Minow

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