This is an urban legend...
" This kind of thing is a common Fortran bug, so there are probably
many different stories going around with a similar theme. Some
of them are probably true. I do know of one such instance that
really did happen, at Nasa.
I worked at Nasa during the summer of 1963. The group I was
working in was doing preliminary work on the Mission Control
Center computer systems and programs. My office mate had the
job of testing out an orbit computation program which had been
used during the Mercury flights. Running some test data with
known answers through it, he was getting answers that were close,
but not accurate enough. So, he started looking for numerical
problems in the algorithm, checking to make sure his tests data
was really correct, etc.
After a couple of weeks with no results, he came across a DO state-
ment, in exactly the form ... indicated above. After changing the
. to a , the program results were correct to the desired accuracy.
Apparently, the program's answers had been "good enough" for
the sub-orbital Mercury flights, so no one suspected a bug until
they tried to get greater accuracy, in anticipation of later
orbital and moon flights. As far as I know, this particular
bug was never blamed for any actual failure of a space flight,
but the other details here seem close enough that I'm sure this
incident is the source of his version of the story.
Sent to Risks by Mark Brader, SoftQuad Inc., Toronto"
http://catless.ncl.ac.uk/Risks/9.54.html#subj1
Joe
On Tue, Mar 29, 2022 at 10:41 AM Robin Vowels wrote:
> Hi David,
> I found this:-
>
> A missing punctuation mark in a guidance equation led to a much greater
> national embarrassment when
> the rocket carrying the Mariner 1 space probe exploded shortly after
> liftoff on July 22, 1962, in
> what is widely believed to the most expensive typographical mistake of
> all time. Some reports
> attributed the rocket failure to a misplaced decimal point, an extra
> semicolon or a comma that was
> entered in place of a period in the coded mathematical instructions that
> guided the steering systems
> on board the spacecraft. However, NASA investigators traced the cause of
> the accident to the omission
> of a single hyphen (or superscripted overbar) in the guidance control
> software, which transmitted a
> series of incorrect course correction signals that threw the vehicle off
> its flight trajectory. The
> range safety officer had no choice but to order the intentional
> detonation of the spacecraft less
> than five minutes after liftoff to prevent the vehicle from crashing
> into a populated area.
>
> The high-profile failure of the Mariner probe to reach its intended
> destination underscores the need
> for periodic proofreading, peer review analysis and rigorous testing for
> performance problems at all
> stages of computer coding and programming. The syntax of a programming
> language requires a highly
> specific sequence of symbols and characters to process information,
> specify external machine behavior
> and direct a computer to execute a set of commands. A simple typing
> error or misplaced character
> could preclude the operating system from translating coded language
> accurately, render an entire
> application useless, or lead to unpredictable or even disastrous
> consequences.
>
> There was intense political pressure to hasten the schedule to launch a
> planetary expedition ahead of
> the Soviet Union and to establish spaceflight supremacy. The single
> missing FORTRAN coding symbol was
> not detected during preflight preparations as a result of the
> accelerated timetable and was largely
> responsible for the loss of the first American spacecraft destined to
> explore another planet. The
> mission failure was a setback for interplanetary space exploration and
> dealt a significant blow both
> to national morale and to the prestige of the space administration at a
> time when the United States
> was losing the space race. When calculating the adjusted costs of
> research, development, training and
> construction, the total losses connected to the accident are estimated
> to exceed $620 million. Never
> in history has so much money or so many resources been squandered
> over the exclusion of a single punctuation mark.
>
> On 2022-03-30 01:31, David Spiegel wrote:
> > Hi Robin,
> > I searched, but, am not yet successful in finding it
> > If I find it, I plan to let you know.
> >
> > Regards,
> > David
>
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