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Happening upon fortunate discoveries when not in search of them!
The time was 1947/46. The place was the White Sands Proving Grounds, an instrumented piece of desert just over the Organ Pipe Mountains to the east of Las Cruces, New Mexico.
The cast of characters included Dr. Werner von Braun a "V-2 Rocket-master", groups of scientists and engineers from various universities and research organizations and the launch crew headed by "Pappy" White of GE.
The plot was to loft scientific payload into the ionosphere on top of V-2 rockets re-assembled from liberated German hardware. The "Ring-master" for much of the scientific activity was the Air Force Cambridge Research
Laboratories (AFCRL), in particular Dr. Marcus O’Day who assembled the expertise of some 28 universities, each assigned a unique mission to solve. (A crater on the Moon is named in honor of his accomplishments.)
One such contract was being pursued by the Upper Atmosphere Research Laboratory of Boston University. Objectives: (1) Can pulse-coded command signals be sent across the continent and received aboard the rocket at high altitudes?; (2) What conditions exist at the "boundary layer" between the skin of the rocket and atmosphere?; (3) Send back television images of the action of the large parachute used to gently(?) lower the instrument compartment back to Earth.
The rocket-borne transmitter used a Western Electric "door-knob" tube (certainly not designed for high impact applications) as the final stage. Other vacuum tubes were purchased "off-the-shelf" at the local radio store; "space-qualified" components weren’t even a "gleam in the eye" at this point in the space program. Sub-miniature tubes were coated with latex to avoid shattering under the impact of launch. Banks of lead-acid batteries drove small motor-generator sets to develop "B-power", housed in pressure-proof containers to prevent boiling off the electrolyte and to prevent corona at reduced atmospheric pressure. A successful launch to an altitude of 65 miles called for a calibration in Juarez, Mexico, just south of El Paso, Texas.
Enter the Transistor: June 30, 1948.
A gleaming search light at the end of the tunnel! A way out of constraints imposed by power, size, weight and reliability on the many electronic equipments required to gain access to space.
Back in 1924 "Radio News" magazine carried an article describing the "Crystodyne Principle", a transistor-like device invented by an engineer at the Russian Government Radio Laboratories and originally reported in "Radio Electricite’" of Paris. It worked, but its trail is lost.
Then in the April 1, 1947 issue of "Radiocraft" magazine, a fictitious Mohammed Ulysses Fips described, and showed photographs of, the "Crystron", an amplifying device identical to Bell Lab’s Transistor, except that he still carried over the unnecessary vacuum and the glass envelope. Footnote: "April Fool!". (It is not now clear who fooled whom!)
After the Bell Lab’s 06-30-48 announcement, there promptly followed a rash of articles in popular radio magazines on how to build your own transistors; notably S.Y. White in "Audio Engineering" and C.E. Atkins in "Radio and Television News", among others. They made it sound so simple!
This was just what the space program needed! Small, light-weight, rugged, very low voltage and power requirements. And it was an excellent thesis subject in Physics, with the bibliography being generated almost daily in the current press and people anxious to share their experimental results.
Germanium 1N21 and 1N21 diodes were in ready supply, and recommended surface treatments ranged from ethylene-glycol (anti-freeze) through various photographic developing solutions to vinegar and wine! (The latter no doubt often used to assuage bruised egos after failed experiments.)
In March 1949, several commercially-produced experimental transistors from two suppliers (Western Electric and GE) were obtained with the aid of the AF Cambridge Research Laboratories, who were anxious to have this new technology available for their space projects.
About a dozen home-made transistors were produced using different electrode configurations; at least half of them evaporated under various "out-of-bound" operating conditions. They exhibited a wide range of operating parameters, but all were capable of producing gain in a variety of conventional circuit applications. The highest useful power gain was about X60, and the highest useful frequency was about one "megacycle per second" (as frequency was called in those days). No unit operated above 10 MHz.
"Conventional Wisdom" precluded their operation at anything above 10 MHz; profound technical papers "proved" the electrons could not possibly move at a faster speed! The phenomenon was attributed entirely to surface effects; the concept of field or bulk effects had not yet surfaced.)
The author of the masters thesis was challenged during orals on his "unrealistic and unbridled optimism" about potential applications in the face of "known limitations". Would that he now could face his protagonists:
"Truth is Stranger then Fiction!"
An early limited use of transistors in space hardware, about 1952/53, was in an AF Cambridge Research Labs 10-channel telemetry unit which used the "back-porch equalizing pulses" of the Boston University TV signal for "pulse-position modulation".
The two ionospheric signal receivers, the TV system and transmitter still used vacuum tubes. The constraints of prime power and weight were so great that they forced placing as much data as possible on the single radio carrier from rocket to ground. The system used simultaneous AM and FM on the same carrier to relay the TV video, two propagation test pulse trains, impact-noise audio and the 10 channels of telemetry to the ground station at Holloman Air Force Base near Alamogordo, New Mexico.
After the end of the V-2 flights, and the introduction of the Aerobee launch vehicle, about 1952/53, a whole new generation of space electronic hardware was born. The new-found design freedom afforded by the Transistor had a major impact on the variety of experiments which could be flown on any one flight. On-board computation become practical. The Transistor had revolutionized the space program.
An early use of Integrated Circuits designed specifically for a space application, about 1961, was the Integrated Circuit Voltage Controlled Oscillator (VCO) produced by Motorola for the Upper Air Sounding Rocket program funded by the AFCRL. This very small rocket, typically flown near the Hudson Bay corona borealis- study station, had no room for conventional transistorized VCO’s. The entire circuit, less calibration Trimpots, was placed in one T0-5 can with no change in performance.
And so it has come to pass that an incidental discovery in one laboratory, studying a general phenomena, has proven to be the indisputable key to the existence of a now major, and rapidly-expanding, part of our daily environment: our presence in space. -WCM
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