Digging through my files I recently found an email which caught my attention:
From: Larry A.
Sent: Thursday October 21, 2004 7:18 AM
TO: A whole bunch of people who are probably retired now
Subject: SMS Issue – SMS AR 018459 – Unexpected GPC Errors – 1141A T.L. – OI30 STS-114 BASE2 FSW (OF03.01) – Closure
After additional runs in the SMS and SPF and analysis of the data collected on those runs, FSW DR 121227 has been opened on the issue. The SMS AR will be closed in reference to the FSW DR. The description of the FSW DR reads as follows:
“In MM 104-105, 202, and 301-302 when an Item 22 (Load) is executed on the XXXXX YYYYY MNVR display, it is possible for 2 SQRT of negative number GPC errors to be generated. This will occur when the TIG entered is not consistent with the PEG 4 burn targets. The Orbital Altitude Time Task in the DIP computes the inverse of the mean orbital rate and the sine of the eccentric anomaly as a function of the square root of the semi-major axis. Given the inconsistency of the TIG with the targets and the fact that the guidance converged to a solution, the semi-major axis is computed as a negative number.”
So here is my problem: almost two decades later I completely understand EVERY BIT of this email!
How many of my memory cells are taken up with holding on to obsolete and totally useless information? Is this why I can go down the hall to another room in my house and, upon arriving there, wonder what it was I came to do?
I imagine that there are dozens, if not hundreds, of former flight controllers, astronauts, trainers, software programmers, and trajectory analysts who were nodding their heads reading that email and saying ‘Yes! I understand the problem!’
Some neuro-psychologist needs to explain to me how to clean out my memory cells of unwanted and useless information so that I don’t get confused looking for my car keys.
Oh well, its fun to remember the old days.
And my wish for you today is that your semi-major axis is never a negative number.