In 1977, I negotiated the lease-purchase of a Harris S123 computer for our Space Plasma Physics research group in the School of Electrical Engineering at Cornell University. This acquisition created a headache for me: I became the default consultant and repair technician, and my own research output was reduced. Yet, there was an ultimate advantage: I became an expert in the Harris Computer System’s software and hardware.
As the consultant, many users asked for help in debugging their programs. Help sessions often began with statements claiming that “the system must have failed because their programs stopped working.” I would reply with a question asking what they changed in their programs between the time the programs worked and the time they didn’t. A typical reply was that their last little change could not possibly be the reason. Of course, upon my examination, those little changes were the culprits and not the system. A number of years later, I seemingly was on my way to falling into a similar trap at the Arecibo Observatory.
In 1985. Dr. Paul Bernhardt of the U.S. Naval Research Laboratory recruited me to run the Arecibo Observatory’s incoherent scatter radar to measure the ionospheric effects of a burn of the shuttle orbital maneuvering system (OMS) engines over Puerto Rico. My incoherent scatter radar experience began at Arecibo in 1969 as a Ph.D. candidate at the Pennsylvania State University and continued in 1972 when I joined the School of Electrical Engineering at Cornell. Dr. Bernhardt and I wanted real-time graphics of the ionospheric electron density profiles, a capability Arecibo did not previously possess. Real time was important to ensure successful results without needing subsequent OMS burns. I wrote a program to use a Tektronix 4010 graphics terminal for plotting the real-time electron density profiles.
The launch of the Challenger for STS-51-F was scheduled for 29 July 1985. On the day of the launch, I decided to make an improvement to my program. Once it was complete, the program failed. I tried backing out the change, but the program still did not work. The observatory’s director, Dr. Donald Campbell, was furious with me. After running tests on different sections of my program, I discovered that there was no response from the antenna pointing system. Unfortunately, the on-site Harris technician was on vacation. I desperately tried to convince the director to let me swap the interface board for the pointing system with one from their other Harris computer. When he relented, the problem was solved, and the other scientists and visitors gathered around me as the density profiles were plotted on the terminal. Before long, there was a spike from a direct reflection from the shuttle and then the subsequent density profiles showed a bite-out as electrons were depleted by the OBS exhaust gasses. The results of the successful experiment were published in Journal of Geophysical Research.
