Chapter seven: Pursuit of Orbit
The main sources of information for this chapter are Bill Guier and George Weiffenbach.
The problems in putting this chapter together were that there are no primary written sources that directly confirm what Guier and Weiffenbach did and when, and they have both told the story several times, including on tape in a 1992 APL video. Thus it took some time to recall memories.
The only way around this seemed to me to go over and over the same ground from as many different angles as possible. And both Guier and Weiffenbach seemed to take to this approach as the proverbial duck takes to water. Each time I gleaned another fact, no matter how small, from one of their colleagues or from a published paper, I went back to one or another of them to ask more detailed questions or the same questions in a different guise. As I learned a little more about the physics for myself, I also went back to them.
The result is chapter seven, which is corroborated as much as possible by memories from other people.
Certain bounds to the time when their work was done are set by undisputed dates, such as the launch of Sputnik II and the day that their work became an official project.
Lee Pryor, who was at that time studying computing at Pennsylvania State University, confirms much of what Guier says about coding for the Univac.
The richness of information available on the Doppler curve (page 75) is apparent in a highly mathematical in-house paper (Part of APL’s Bumblebee series) “Theoretical Analysis of the Doppler Radio Signals from Earth Satellites” published in April 1958.
Charles Bitterli remembers working on an algorithm for least squares (page 78).
Henry Elliott’s memories corroborate Weiffenbach’s view of himself as a painstaking researcher who would check the quality of data in detail (page 79).
Chapter eight: From Sputnik II to Transit
Project D-54, to determine a satellite orbit from Doppler data, APL archives (page 82).
Guier and Weiffenbach’s briefing about their work (page 82) is from my interview with Harold Black.
Information about Guier’s and Weiffenbach’s early work on the ionosphere (page 82) is from interviews with Weiffenbach and Guier.
A textbook consulted on ionospheric refraction is The Feynman Lectures on Physics, volume one, chapter 28 (Addison Wesley, 1963).
Weiffenbach’s memo to Richard Kershner and the first Transit proposal (pages 84 and 85) are in the archives of the Applied Physics Laboratory
Henry Riblet told me of the need to modify the design of circularly polarized transmitters for Transit’s spherical surface (page 85).
Information about O’Keefe and his views (pages 85 and 86) came from my interview with John O’Keefe.
Views about Frank McClure’s character (page 87) came from nearly every member of the Transit team that I interviewed.
Frank McClure’s ideas for a navigation satellite are in a memo dated March 18, 1958, reproduced in The First 40Years, JFIUAPL (Johns Hopkins University Press).
What McClure said to Guier and Weiffenbach about his satellite navigation idea is a story that both told me separately (page 88).