1965 NASA failure has been traced to an engineer's scrawled (and misread) instructions

My wife's student is doing some work on handwriting and medication
errors. He found a reference to a NASA failure in 1965 due to misread
handwriting, but no other information. Has anyone heard of something
like this? My google search hasn't found anything except for a brief
mention on the webpage
http://www.global2000.net/handwritin...r/KateHwR.html

Thanks for any replies.

In article ,
Rayc wrote:
My wife's student is doing some work on handwriting and medication
errors. He found a reference to a NASA failure in 1965 due to misread
handwriting, but no other information. Has anyone heard of something
like this?

This is probably -- not certainly -- a reference to the loss of Mariner 1
in a 1962 launch failure. That was traced to a combination of problems,
one of which was the omission of a bar over a variable name in a
hand-written guidance equation.

The bar denoted smoothed data, averaged to clean out noise from the
measurement process. With no bar, the noise was seen as erratic
fluctuations in velocity, which required corrections. The result, once
that guidance equation became relevant due to a failure elsewhere, was
erratic behavior of the rocket due to the misguided corrections. This
alarmed the Range Safety Officer enough that he destroyed the rocket.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

(Rayc) wrote in message . com...
My wife's student is doing some work on handwriting and medication
errors. He found a reference to a NASA failure in 1965 due to misread
handwriting, but no other information. Has anyone heard of something
like this? My google search hasn't found anything except for a brief
mention on the webpage
http://www.global2000.net/handwritin...r/KateHwR.html

Thanks for any replies.

I'm not aware of the year, but I do know NASA lost a $25 million
satellite because of a minus (-) sign being inserted in a formula
rather than a plus (+). Perhaps this is what he means?
LaDonna

This reminds me of a story about the development of the automated
radar intercept system on the F-86D. In its first tests, as the Hughes
radar achieved target lock - lost it - locked - lost it - the linked
aircraft autopilot was heaving the airplane all around the sky. Very
exciting for the test pilot. Had to tweek the latency a bit ....


(Henry Spencer) wrote in message ...

erratic behavior of the rocket due to the misguided corrections. This
alarmed the Range Safety Officer enough that he destroyed the rocket.

"Henry Spencer" wrote in message
...
In article ,
Rayc wrote:
My wife's student is doing some work on handwriting and medication
errors. He found a reference to a NASA failure in 1965 due to misread
handwriting, but no other information. Has anyone heard of something
like this?

This is probably -- not certainly -- a reference to the loss of Mariner 1
in a 1962 launch failure. That was traced to a combination of problems,
one of which was the omission of a bar over a variable name in a
hand-written guidance equation.

The bar denoted smoothed data, averaged to clean out noise from the
measurement process. With no bar, the noise was seen as erratic
fluctuations in velocity, which required corrections. The result, once
that guidance equation became relevant due to a failure elsewhere, was
erratic behavior of the rocket due to the misguided corrections. This
alarmed the Range Safety Officer enough that he destroyed the rocket.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |


Henry reminded me that this was one of the first lessons in my
computer programming class (WATFOR in the 1970s)

The Mariner 1 failure was apparently caused by a combination of two factors.
Improper operation of the Atlas airborne beacon equipment resulted in a loss
of the rate signal from the vehicle for a prolonged period. The airborne
beacon used for obtaining rate data was inoperative for four periods ranging
from 1.5 to 61 seconds in duration. Additionally, the Mariner 1 Post Flight
Review Board determined that the omission of a hyphen in coded computer
instructions in the data-editing program allowed transmission of incorrect
guidance signals to the spacecraft. During the periods the airborne beacon
was inoperative the omission of the hyphen in the data-editing program
caused the computer to incorrectly accept the sweep frequency of the ground
receiver as it sought the vehicle beacon signal and combined this data with
the tracking data sent to the remaining guidance computation. This caused
the computer to swing automatically into a series of unnecessary course
corrections with erroneous steering commands which finally threw the
spacecraft off course.

gb

"G.Beat" wrote in message
news:sabwc.52761$Ly.23754@attbi_s01...
Henry reminded me that this was one of the first lessons in my
computer programming class (WATFOR in the 1970s)

"You want me to learn this? WATFOR?"

I used to have a copy of that. Still might, if the 5.25 floppies haven't
demagnetized. I trained on Fortran77, mostly because I thought it sounded
interesting and I had a free period. After TRS-80 BASIC, it was pitifully
simple.

In article ,
(Encyclopedia Astronautica) writes:
This reminds me of a story about the development of the automated
radar intercept system on the F-86D. In its first tests, as the Hughes
radar achieved target lock - lost it - locked - lost it - the linked
aircraft autopilot was heaving the airplane all around the sky. Very
exciting for the test pilot. Had to tweek the latency a bit ....

The early Hughes Fire COntrol Systems had a bunch of teething problems
to deal with. (Beyond the reliability issues of building a fiarly
high-powered radar and analog computer that will work at high
altitudes in a fighter-sized airplane using Vacuum Tubes and
Wire-Wound Delay Lines. (Stome Knives & Bearskins indeed!).

In addition to the Usual Uncertainties that come from using a Radar as
a data source (The reflection is based on the centroid of teh target,
which is always changing, so with unsmoothed data, the target wobbles
around, * glints & dims) there were various bits of slop in teh
tracking loops of the Fire COntrol Computer, leading to a phenomenon
known as "Dot Wander" (The Attack Presentation of the system was a
circle, representing the Allowable Steering Error, whuch changed
diameter to reflect both the "Time to Go Until Firing" and the need
for increased accuracy at that point, and a Steering Dot that
represented the bearing change of the target in relation to the
shooter. (It was a Collision Course system - the fighter maintained a
Constant Bearing course on the target (Actually the Firing Point for the
rockets) It all sounds simple, but in practice, it took a lot of
effort and training. The Radar had a tendency, when the target blip
crossed the Ground Return echo on the scope, to shift lock from the
target to the ground. Any maneuvers by the target resulted in a new
targeting solution, and the interceptor had to maneuver accordingly.
(In other words, the happily centered dot that you've been following
shoots off in some random direction.) This is a real PITA for teh
pilot, ecpecially in a single-seat airplane like the F-86D, where he's
the Pilot and Radar Operator all in one. So - a solution was found by
implementing a system called CSTI - (Control Surface Tie-In). This
linked the error signal that drove the Steering Dot to the Autopilot.
Wherever the Dot would go, the airplane would maneuver to follow. An
excellent idea, and one still in use today - but i its early
implementations, it, uhm, needed a bit of work. There wasn't any
buffering in the system - It just Banked & Yanked to put the dot back
in the center (Rolled so that the airplane's pitch axis was in-plane
to the target & applied G to move the nose. Fairly simple really).
This was fine, except that the early systems just applied a full
command to the roll & pitch controls, and the pilots found themselves
thrown all over as the airplane chased the quivering, scintillation
radar target.

There were aother problems, as well. When intercepting a _big_
airplane, like a B-36 (Especially a propeller-driven airplane), as the
range closed, the target would resolve as a number of discrete
targets. (For example, in the B-36 case, the fuselage and the 6
propellers) The radar would jump lock from one to another of these
targets as it approached, and that would screw up the tracking solution.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster