EXPERIENCE RESUME OF GAINES M. CROOK, P.E.
May 2000
1. EDUCATION
BS in Electrical Engineering, University of South Carolina, 1952.
Extension Courses
UCLA
Digital Computers
Transistors
Government Contracts Administration
Space Science
L.A. Pierce College
Philosophy
Cal Poly, Pomona
Microprocessors
2. Employment History
February, 1972 to 1999
Self Employed, Gaines M. Crook & Associates/GMC LABS,
January 1959 to February 1972
Ramo-Wooldridge / Space Technology Laboratories / TRW Systems, Redondo Beach, CA.
Member of the Technical Staff/Section Head/Department Manager/Senior Staff Engineer.
June 1956 to December 1958
Douglas Aircraft Co, Inc., Missiles Div., Santa Monica, CA.
Design Engineer/Group Leader.
May 1953 to May 1956
E.I. duPont de Nemours & Company, Savannah River Plant, Aiken, South Carolina.
Instrument Engineer.
August 1951 to May 1953
Miller Electric Company, Aiken, S.C.
Electrical Engineer.
3. Technical Experience
Digital Computers, Circuits and Applied Techniques
Designed digital systems and digital circuitry for many space physics experiments, also in experiment GSE. Designed a scanning magnetometer for measuring magnetic fields to 10-6 of Earth's field at 12 locations, recording it on punched paper tape compatible with computer inputs for computer analysis. Designed a data storage unit and controller for commercial application. I am thoroughly familiar with coding, decoding sequencing and data translating logic networks, counters, registers memories A to D and D to A converters and the general subject of microprocessors.
Data Transmission
Designed analog and digital data links for many types of systems considering data acquisition rate, commutation, de-commutation, Nyquist rate and information bandwidth, filtering, PLL, synchronous detection and correlation. Computed complete satellite to ground communication budgets. Designed a whole facility for extracting analog signals from very noisy tapes and presenting the spectral content in frequency time diagrams identified in real time to one second. Received U.S. Patent 3,566,088 on a correlator. Designed a data acquisition system for a locomotive wheel tester. Designed a digital data transmission system for converting analog data from a "rheometer" (a device for measuring the viscosity of molten PVC used to manufacture phonograph records) and transmitting it to a remote data terminal and computer.
Radio Propagation
Ionospheric radio propagation at very low frequencies through high frequencies. Designed a trans-ionospheric propagation experiment. Did depolarization and scintillation studies. Nuclear blast EMP propagation. Made measurements of the electromagnetic pulse (EMP)of the July 1962 "Starfish" explosion (published Journal of Geophysical Research Vol. 68, NO. 6, March 15, 1963). Path loss calculations and power budgets for space communication.
Electromagnetic Field Measurements
Established and operated for 16 years an EMC laboratory with a 12'x12' shielded room in Chatsworth, CA and an open field test site in the Mojave Desert/Tehachapi Mountain area of Kern County, CA in conformance with the requirements of ANSI C63.4 and the Federal Communications Commission. Electromagnetic emission tests are planned and conducted
under Part 15, Subparts B and C and Part 18 of the FCC rules, which was continued until December 1996.
Microwave Point to Point Communication
Site selection and path loss calculations, installation design, remote control and monitor system design. Invented a portable analog computer for calculating 1st Fresnell zones in the field, while selecting routes.
Scientific Spacecraft Physics Experiments
Was completely responsible for 20 experiments of the energetic particle and electric, magnetic and electromagnetic field type. This included Project Management, experiment design and most of the detailed circuit design. Never a failure of any kind. After it's designed mission was completed, NASA turned off Pioneer 9 for a period of 17 years after which it was again turned on. The only experiment which was still operative was our plasma wave detector and it was operating normally.
These experiments included Plasma Wave Detectors for spacecraft P-11, OV2-1, OV3-3, OV2-5, OGO-5, Pioneers 8, 9, and 10, IMP-H, and the Pioneer-Venus orbiter. Assisted in the design of several magnetometers, micrometeroid detectors, curved plate analyzers, and mass spectrometers. Designed a time-of-flight mass spectrometer micrometeoroid experiment for the "Grand Tour" Mission (which was never built).
Computer Use
Proficient in the use of the IBM PC computer.
Primary and Secondary Standards
Calibration of instruments and responsibility for standards. Development of a 1 ppm programmable power supply for driving a 23' three axis magnetic Fensalau Coil for nulling Earth's field.
Test Equipment
General purpose, missile system, RF equipment, counter-countermeasures systems, special purpose, integrating gyro, rate gyro. Design, development, system test requirements analysis, production design, circuit design, complete test systems and consoles, turntables. Space experiment test equipment and many others.
Radar
Counter-countermeasures (jammer locaters) installation, data systems. Integration, installation design, control system design, antenna criteria.
Micro-magnetics
Designed equipment for the measurement of very small magnetic fields of spacecraft and components (10-6 gauss) as well as very large Helmholz coil systems and controls. Designed and built several large magnetizer/demagnetizer coils 3'to 11' in diameter while employed by TRW, Inc. A 46"x 46" coil system with a digital controller was designed and built for Martin Marietta Corporation, Denver, CO, under contract to Gaines M. Crook & Associates.
Electrostatics
Have done considerable work on electrostatics and the detection and measurement of electric fields and electrostatic (plasma) waves in space. Originated the short capacitive (wire cage) dipole method of E-field measurement and designed and built the instrumentation which first measured electric fields in the ionosphere and magnetosphere with a very short dipole,(satellite 1964-45A). Invented the "Virtually Coexisting Spheres" electric field sensor. Did considerable work on the equilibrium charge on spacecraft in orbit. Was a consultant to the German Government Space Agency (Gesellscraft fur Weltraumforschung) and to ERNO Raumfohrttechnik, a German Company on the subject of equilibrium charge on orbiting spacecraft.
Electronic Design and Fabrication
For six years I operated the Advanced Techniques Department within TRW Systems. This Department wasa "self-contained" design and fabrication activity which incorporated the system design, electronic design and mechanical design and mechanical and electronic fabrication into one integrated unit. Space Physics experiment packages were designed and built to all levels of Quality Assurance without a single failure in space.
Since having my own company, we have designed and built several pieces of equipment for other companies, under contract, including a Surge Generator to simulate lightning stroke effects as required by Part 68 of the FCC Rules, several telephone loop simulators with ring generators, a magnetizer/demagnetizer coil and controller, several special data acquisition systems.
Electromagnetics
Many propagation problems relating primarily to the atmosphere-ionosphere, magnetosphere interface. Designed equipment and measured the electromagnetic pulse (EMP) from the 1962 "Starfish" nuclear explosion in space with homemade equipment in my garage in Canoga Park, CA. Designed many antenna systems. Measurement of electromagnetic fields for control of electromagnetic interference.
Telephone Terminal Equipment Testing
Established a Telephone Terminal Equipment Test Facility in 1974 and which has tested, "Certified" and Registered thousands of pieces of terminal equipment for companies throughout the United States, Taiwan, Japan, Korea, Italy, Hong Kong, United Kingdom, Malaysia, Indonesia, Australia and Singapore. This is still my primary business activity, although at a very low level.
Physics
During the period from 1962 through 1971, I became very involved with the various aspects of physics and completed a number of assignments in physics. I am especially qualified in communicating with physicists and reducing their requirements for experiments to practice.
Artificial Heart
In a design study for the Atomic Energy Commission, I designed the powercontrols, safeties, motor controls and mechanical mechanism for a plutonium powered implanted ventricular bypass pump with a projected lifetime of ten years.
Power Plant
Steam, diesel, gasoline, including instrumentation and control. Installation design, control design system sizing, facilities criteria, instrumentation design. Closed cycle Rankine Portable Power Plant Controls Design.
Power Distribution
Line, substation, industrial plant, lighting. Installation design, sizing, mechanical design of prefabrcated substation conduit installation.
Nuclear Reactors
Rod control systems, period meters, power calculators, charge and discharge machines. Maintenance analysis, test equipment design, instrument design, controlc ircuit design.
Nuclear Instrumentation
Personnel monitor, floor monitors scintillation spectrometry, linear pulse amplifiers, water monitors, proportional counters, neutron chambers (BF and compensated), Geiger counters, scintillation counters, electrometers, space physics particle detectors. Circuit design, detector probe design, circuit analysis, calibration methods design, fabrication and integration.
Motor Control
Crane and door control up to 300 tons, remote hot cell actuators, motors to 3,000 HP. Installation design, control system design, equipment specification. Slow speed torque motor servo control.
Mechanism
Many mechanisms including a reciprocator for artificial heart pump. Specialist on differential gearing. Holds a patent (3,468,191) on a binary control gear train. Holds a patent (3,397,586) on a differential mechanism for quick reverse orienting three axes of orthogonal magnetic field sensors on a spacecraft.
Optical Instrumentation, Ultraviolet and Infrared Radiometers
Electronic system design including low noise with mechanical choppers. Surface to air missile detectors. Meteor Flash Analyzer space experiment, gas dynamic laser temperature profile plotter.
Miscellaneous
(1) Designed a miniature but highly efficient electronic ignition system for a rocket engine.
(2) Designed the motor actuator system for an artificial heart, including a power load sharing system, electronic speed controls, motor commutation system, power converter and sized the rotating gear train.
(3) Have designed many solid state power inverters.
(4) While I received my degree in electrical engineering, I have considerable experience in mechanical engineering, especially mechanism and gearing and I am a Registered Mechanical Engineer in California.
(5) Invented and patented a binary controlled geartrain which produces a ratio determined by a binary coded input.
(6) Developed and patented a controller for gasoline driven generators in the 5 KW class which causes the generator to start and furnish 120/240 VAC power to a load connected to it within 3 seconds of when the load is turned on and run as long as power is needed and to shut the generator engine down after a preset timeout period is completed from when the load is switched off. A patent application for improvements was filed and has been allowed and will be issued in the first half of 2000.
MANAGEMENT EXPERIENCE
(1) Group Leader, Thor Missile Test Equipment, Douglas Aircraft, Missiles Div.. Supervised 60 engineers. Responsible for test equipment design and fabrication. Contract value -- $10 Million.
(2) Section Head and later Project Engineer of AN/TLQ-8 Counter-Countermeasures System at Ramo Woolridge. Supervised 25 technical people. Responsible for field deployment site selection, installation and field test. Contract value -- $5.5 Million.
(3) Section Head, Spacecraft Integration, Space Technology Labs. Supervised 20-25 people.
(4) Project Manager, OGO-E Plasma Wave Detector Project. TRW Systems, contract value $1.3 Million.
(5) Project Manager, Pioneer Electric Field Detector Project. TRW Systems - contract value $235 K.
(6) Assistant Project Manager for Scientific Experiments for the Particles and Fields Satellite Project.(This was a scientific spacecraft that was launched into an orbit around the moon from the Appollo 16 spacecraft.) TRW Systems - contract value (experiments) $1 Million.
(7) Department Manager, Advanced Techniques Department, TRW Systems for 5 -3/4 years. Department's burdened expenditure rate was about $400 K/year.
(8) Very active in proposals and have managed and contributed to many proposals.
(9) In 1972, I left TRW and became self employed as a design consultant, under the name of "Gaines M. Crook & Associates". In 1974, there appeared to be an opportunity for testing telephone terminal equipment for "Certification" under the auspices of the California Public Utilities Commission. Due to my considerable experience in the interpretation of specifications and design of equipment to test to specific specifications, I decided that I would enter this activity. Later (late 1975) the FCC preempted the CPUC in the terminal equipment field with its "Registration" program under Part 68 of its rules. I then established my company as a qualified laboratory to perform this work. This was the prime support of the company, since. In 1978, the name of the company was changed to GMC Laboratories, after my initials. When the FCC established Subpart J of Part 15 of its Rules requiring the measurement of the electromagnetic emissions of electronic equipment we decided to become a qualified laboratory in this field also, since by this time much of the telephone terminal equipment we received for test contained microprocessors and had to be tested for Part 15, Subpart J also. This deals with the measurement of electromagnetic interference generated by electronic equipment. This activity continued until the end of 1996. The business closed with my retirement in 1999.
ADDITIONAL DATA
[1] Registered Professional Engineer in California in both Mechanical and Electrical Engineering.
[2] Senior Life Member, Institute of Electrical and Electronics Engineers.
[3] Member, (although not active in many years) US Commission IV (Magnetospheric Radio) of URSI (International Scientific Radio Union).
[4] Author or coauthor of 14 technical papers for scientific journals and a chapter in the book, Plasma Waves in Space and Laboratory, edited by F. O. Thomas and B. F. Landmark, Edinburgh University Press.
[5] Selected by NASA Headquarters Office of Science and Technology as Principal Investigator for a Plasma Wave Detector Experiment (E-24) on the OGO-E spacecraft.
[6] Acted as a consultant to the German Government Space Agency (Gesellschaft fur Weltraumforschung) on matters of magnetic fields and electrostatic equipotential surfaces on spacecraft (spacecraft charging).
[7] Member of the 1967-1969 TRW Corporation's "Future Probe" technology forecasting team.
[8] Holds eight patents and an additional one has been allowed and will be issued shortly.
[9] F.C.C. Radiotelephone, General Class License (formerly First Class).
[10] Acted as expert witness for Pacific Bell in a court case with Phonetele, Inc., concerning the registerability of the Phonemaster toll restrictor. Also have been retained by Pacific Bell legal Dept. concerning in other matters.
[11] Past-President of the San Fernando Valley Chapter of the California Society of Professional Engineers.
PARTIAL LIST OF PUBLICATIONS
Crook, G.M., E.W. Greenstadt and G.T. Inouye
Distant Electromagnetic Observations of the High Altitude Nuclear Detonations of July 9, 1962.
J.Geophys. Res., 68, 1781, 1963
Scarf, F.L., G.M. Crook, and R.W. Fredricks
Preliminary Report on Detection of Electrostatic Ion
Waves in the Magnetosphere.
J. Geophys. Res., 70, 3045, 1965
Scarf, F.L., G.M. Crook and R.W. Fredricks
Survey of VLF Electric Fields in the Magnetosphere with the Polar Orbiting Spacecraft 1964-45A
Radio Science, 1, 939, 1966
Scarf, F.L., R.W. Fredricks and G.M. Crook
Detection of Electromagnetic and Electrostatic Waves on OV3-3
J. Geophys., Res. 73, 1723, 1968
Scarf, F.L., G.M. Crook, R.W. Fredricks, I.M. Green and C.F.Kennel.
Observation of Plasma Waves in Space. Plasma Waves in Space and in the Laboratory. (Edinburgh University Press, 1969)
Scarf, F.L., G.M. Crook, I.M. Green, and P. Virobik.
Initial Results of the Pioneer 8 VLF Electric Field Experiment.
. Geophys. Res., 73, 6665, 1968
Fredricks, R.W., C.F. Kennel, F.L. Scarf, G.M. Crook and I.M. Green.
Detections of Electric Field Turbulence in the Earth's Bow Shock.
Phys. Rev. Letters. (no date)
Crook, G.M., F.L. Scarf, R.W. Fredricks, I.M. Green and P. Lukas.
The OGO-5 Plasma Wave Detector: Instrumentation and In-Flight Operations.
Invited Contributions for the IEEE Transactions on Geoscience Electronics: Special Issue on Orbiting Geophysical Observatory Instrumentation, 31 Jan. 1969
Scarf, F.L., C.F. Kennel, R.W. Fredricks, I.M. Green and G.M. Crook.
AC Fields and Wave Particle Interactions.
Particle and Fields in the Magnetosphere.
Edited by B.M. McCormac, D. Reidel Publishing Co.
Dordrecht - Holland 1970
R.W. Fredricks, G.M. Crook, C.F. Kennel, I.M. Green, F.L. Scarf, P.J. Coleman and C.T. Russell.
OGO-5 Observations of Electrostatic Turbulence in the Bow Shock Magnetic Structure.
J. Geophys. Res., 75, 3751, 1970.
Crook, Gaines M.
A Binary Controlled Transmission
Paper presented at the American Society of Mechanical
Engineers Mechanisms Conference and International on Gearing Gearing and Transmissions, San Francisco, California, October 8-12, 1972. Published in ASME Paper 72-Mech-59 Mechanism Case Studies, R.S. Berkof, American Can Co., Princeton, N.J.
Crook, Gaines M.
Designing to Pass Part 15
IEEE/Wescon invited paper presented at the 1986 Wescon Show & Convention, Anaheim, CA, November 18-20, 1986 and published in the "Professional Program Session Record 37".
Career Highlights
A. At Miller Electric, I was Building Electrical Engineer in the construction of the 105-P Nuclear Reactor Building at the Savannah River Plant of the AEC.
B. At duPont, I was engaged in the design/redesign of instrumentation. including nuclear instrumentation, for the Savannah River Plant, except during startup of the 105-P Reactor, I was 105-P Instrument Shift Engineer.
C. At Douglas Missiles Div. I was responsible for the design of the THOR missile test equipment, both for the R&D and Final Test equipment. I also established a Company Inertial Gyroscope Test Facility which was for all programs.
D. At TRW, I started with the assignment of Installation and Integration of the AN/TLQ-8 Electronic Warfare System (Jammer Locator), first at AF Rome Air Development Center, Rome, NY, and then disassembling it and installing it at the Experimental Sage Radar at South Truro, MA on Cape Cod. These installations involved a number of broad band radar video microwave point to point relay stations which had to be sited and installed. My next assignment was as Integration Section Head and principal Integration Engineer for the OGO Spacecraft. Next, I was Staff Engineer to the Laboratory Director and worked on planning and proposals. Here I was responsible for the Test Philosophy and planning for a major missile system proposal. Next, I moved to the Space Physics Department of the Physical Research Division, as a design engineer to be involved in the design of physics experiments to be flown on various spacecraft.
My first assignment was to respond to an RFP from the Atomic Energy Commission to design a system for fighter aircraft that would detect the electromagnetic pulse (EMP) from the explosion of a nuclear weapon and feed an electronic signal to the photochromic glass windshield of the aircraft, to blacken it in time to prevent the pilot being blinded by the flash from the nuclear explosion. I found that the longer lasting components of the EMP are in the same VLF frequency range as the sferic signals caused by lightning strokes, even though the EMP signature is different from sferics and some method of discrimination between the two must be provided. Sferic signals travel long distances and even bounce from one hemisphere of the Earth to the other. We lost the contract, but I became interested in sferics and built a setup with which to receive them at home in my garage. I could look at the waveforms as they occurred on an oscilloscope.
Not long after this, we got word that the Air Force planned some EMP tests to be done at Johnson Island, in the pacific, where they would launch a Thor missile into the magnetosphere and explode n nuclear weapon there. Some colleagues had magnetic field equipment set up at our magnetic test site in Coral Canyon, west of Malibu, and they planned to monitor the perturbations in the Earth’s magnetic field caused by the disturbance in the magnetosphere at that location. After loosing a lot of sleep many nights (and still working in the daytime) while the AF had bad luck with launches. On July, 9, 1962, they launched the “STARFISH” shot and it was successful. I not only received the EMP signal and recorded it on a tape recorder, but I got an oscilloscope waveform picture of it in my Canoga Park, CA garage, 6000 miles from the explosion. I made the presentation on the results for both the EMP and the magnetic field disturbances at a classified meeting at Hanscome AFB, MA. Later we were able to publish our results in the Journal of Geophysical Research because we did not have an Air Force Contract. Those who had contracts were prohibited from publishing!
I was busy as could be designing circuitry for various spaceflight experiment experiments for many months when one day one of the physicists from the Aerospace Corp. came over to our Department and asked if anyone there could provide a VLF experiment for the Air Force P-11 spacecraft. Since I was the only one in the Dept. with any knowledge or interest in this matter, the Department Manager, Dr. Alan Rosen asked me if I could provide such an experiment. I said, “Of Course”! I did a paper design to estimate what would be involved. The deal was, I would design and breadboard the experiment on my own time and Al Rosen would provide $10,000. in Department IR&D funds to build it. This was a rock bottom affair since experiment contracts were seldom funded for less than $250,000.00.
I used the same electric field antenna with a capacitive coupling network, that I had designed for the EMP detector and was using in my sferics detector at home. This way, input level calibration was very simple, and if required we could switch input level ranges in orbit, depending on what we actually encountered. I encountered a fierce disagreement from certain Department members that an electric field detector would not detect anything since electric field signals were expected to be suppressed in the magnetosphere by the magnetized conducting media. I went on to show that with the weight and power budget we had been allotted, that a magnetic detector design was not feasible so I was allowed to proceed with the electric field design.
In several months, the experiment was designed, tested and delivered to the Aerospace Corp to await integration and launch. And I got busy with other things. I was always working on several things at one time. About a year and a half had passed since the experiment had been delivered to Aerospace, when, one day, Al Rosen came to my office with a nice looking young man whom he introduced as professor Fred Scarf from the University of Washington.
Professor Scarf explained that his field of specialty was plasma waves in space which he said were in the VLF frequency range, below 200 KHz. He began to describe the kind of experiment that he would like to see, and was sketching a block diagram of it on a pad. When he got through describing his dream experiment, I told him that we had already built the experiment that he wanted and that it was waiting to be launched, his response was: “You are pulling my leg!”. When I went and got the file on the “P-11” experiment and showed him the block diagram, schematics and photos of it, he was almost walking on air! That was the beginning of a long and pleasant relationship with him. He came to work for STL and we worked together for many years.
When the data from the P-11 (after launch it was called 1964-45A) came in, we had plenty of data, much of it telling us the errors made in the way the experiment was designed, such as not using a balanced input stage. This was very valuable in allowing us to correct the design of the next generation. As for the idea that there were no electric fields present in space, they were dead wrong. The “naysayers” had a lot of crow to eat, but I never mentioned it to them.
I designed 12 Plasma Wave Detector Experiments. There were some others after my time there. Fred kept up the great work with experiments on some of the interplanetary spacecraft. He was later named TRW Systems’ (which STL had grown into) Chief Scientist, until his untimely death in 1988. The most grandiose of all was Experiment 24 of OGO-5, which had about everything that one could imagine on it. The details of this experiment can be found today on the National Space Science Data Center Web Site.
In addition to plasma wave detectors, I designed eleven or 12 other space flight experiments and one military project. This was a solar blind radiometer to detect short spurt of ultraviolet emitted when a missile is fired, the grandfather of the present day technology which is planned to be installed in airliners to defeat shoulder fired, ground to air missiles by terrorists.
During the period of almost 10 years while I was designing space experiments, I had another responsibility. STL/TRW was in the business of building scientific spacecraft. Scientific spacecraft almost all carry magnetometers. This means that the spacecraft has to me “clean” magnetically, which, in itself, means that the magnetic field due to the spacecraft, at the position of the magnetometer, can not be greater than one gamma (nanotesla). On order to achieve this level of magnetic cleanliness, there is a great deal of effort put into measuring all of the components that go into the spacecraft, Components, down to the hardware level are measured for magnetic fields, each of the complete assemblies are also measured, and when the spacecraft is finally assembled, the whole spacecraft is measured for magnetic fields. One of my duties during this whole period was to provide equipment to fit the job, whatever the job. Simple basic magnetometers are commercially available and the Magnetic Measuring Group bought their own magnetometers, but for anything that was the least bit special, (that one cannot buy out of a catalog) I was responsible to provide it. For instance, I designed and had built a rather complex mechanical fixture for measuring the X, Y, and Z components of the magnetic field of the spacecraft parts and assemblies. The next one was more involved. It was a Magnetizer/Demagnetizer unit. This unit was required to produce a 30 Gauss maximum field. It was further required to demagnetize by switching the field on in a positive direction, switch off, switch on with the field reduced somewhat in the reverse direction, and repeat the process until the field was extremely small. After this process, the demagnetizing cycle was complete.
The grandfather of the above described process was the system used by the Navy to demagnetize ships. They connected a very large DC generator to the demagnetizing coil through a periodically reversing relay that reversed every few seconds. They got the motor driving the generator up to full speed, turned off the motor and on the reversing relay and just let the generator coast down until it stopped and the process was complete.
I designed a controller for the demagnetizer using some of the first commercially available “digital” building blocks available (cira 1962-63), from which I built a reversible 8 bit counter. Each of the “blocks” was 2”X2”X ½ “ in size and the choice of the kind of block was limited to flip flops, “and” gates and “or” gates and external drivers. These were built by Harmon Kardon and required three power supplies. I built the D/A converter from scratch, also. It was composed of a resistor network switched by eight mercury wetted relays for precision, from which the voltage output was fed to the reference voltage input of a Kepco 36 volt, 30 amp power supply. The voltage decrement for demagnetizing was achieved by starting the counter in the “all 1s” state and as it counted down in reverse, the power supply output to the coil decreased. The “quasi-exponential waveform shape was generated by moving the counter input to a successive counter stage as time progressed.
The coil was wound on an aluminum form 4 feet in diameter and 4 feet long which was split and insulated to eliminate the “shorted turn” effect. Even with these crude modules, this unit operated dependably for at least ten years, after which I wasn’t around to know what happened.
Another big project in magnetic measurements was a 12 channel magnetometer. The OGO Spacecraft had a specified maximum magnetic field at the end of the magnetometer boom, 16 feet from the spacecraft center, of 1 Gamma (nanotesla). How was that to be measured? The theoreticians said it could be determined if many field measurements were taken at four distances from the spacecraft, then the field could be calculated by a spherical harmonic procedure . The problem was that many thousands of individual calculations must be made and the Earth’s field was not at all stable and had to be nulled out between measurements, so the measurements would have to be made very quickly, and there were many, many to be made. The verdict was that they could not possibly be made by recording data and transferring it to punched cards. At that time, there was only one way to record data and enter it directly into the computers of 1964. That way was to record the data on punched paper tape and feed the tape into the computer. I found a Hewlwtt-Packard digital voltmeter which had an EBCDIC code output which matched the computer input format and a Teletype data paper punch that could punch 120 samples per second on to paper tape. The 12 individual channels of the magnetometer (three axes per magnetometer position) could be multiplexed with a mercury wetted relay multiplexer into the digital voltmeter and it would provide all of the commands for the paper punch. It worked fine but the punch (the model of which was BRPE) was the noisiest piece of equipment I ever worked with. The four extra channels on the multiplexer measured the temperature of the four three axis magnetometer sensors. The system performed perfectly and the measurement found that after data reduction, the spacecraft field was 1.5 gamma, ½ gamma above the limit, which meant that the spacecraft had to be demagnetized.
BUILDING THE 12 FOOT COIL FOR DEMAGNETIZING THE SPACECRAFT.
The OGO Spacecraft schedule was stalled by the out of specification magnetic measurement. There was the cost of the whole project which was quoted at $25,000 per day of delay. The powers that be got the purchasing department into gear on asking for bids on building an eleven foot, inside diameter coil to demagnetize the spacecraft. The fastest delivery that any contractor gave was 6 months. Soon after hearing the news from purchasing, I was asked when I could have a coil completed. My answer was that I didn’t know, but it certainly would not be 6 months!
I was given the go-ahead to build the coil. The first thing I did was to tell purchasing to find the largest amount of magnet wire in the Los Angeles area in a size between #6 and #12. My idea was to base the design on what was available instead of a pre conceived notion of what is simplest. They found 1500 # of #9 copper in stock. I drew up a sketch of what I wanted the coil form to look like. It was an octagon shape, which is almost as perfect for a coil and is much easier to build. The axis was vertical and it stood on 8 6” aluminum pipe legs, each with a caster with a 10” wheel. The winding space was 20 inches, however the overall height was about 5 feet. I ordered the form, which was split and insulated in order to avoid the shorted turn problem, to be made in 2 halves, because the building where it had to be used did not have a door big enough to admit a 12 foot form, and the coil had to be wound inside the building!
The form, the wire, a big load of fiberglass cloth insulation and 15 gallons of Shell Epon epoxy were delivered to the building, which was in Corral Canyon, off California highway 1, west of Malibu, CA. The Mechanical Technician crew was put at my disposal. I had already decided how we would turn the form, however the mechanical foreman had ideas of his own and wasted almost a half day trying to wrap a belt around the coil form and twist it and loop it over the front wheel of his Corvair car to power it with the car engine, and all it would do was to slip off. When he got through playing I brought in my 2 wheel, gasoline powered garden tractor and had them hoist it up and lower it into the inside of the form and lash it to the form. They already had a 12” steel beam bolted across the bottom of the form for which the center was equipped with a bearing and a 2 inch steel shaft was welded to a steel plate bolted to the floor. Powering it was simple. One man would get inside the form and stand on the cross beam and operate the tractor. And, this put us in business. For three days and three nights the form was turned and the wire was wound on it, stopping only long enough to paint each layer of wire with epoxy and put on a coat of fiberglass.
Eight days from the day I was given the go-ahead, we had a completed and tested demagnetizer. We had added a second power supply to an existing controller to furnish the required power and control.
After my days of designing experiments, I served as the Sub Project Manager for Scientific Instruments for the Particles and Fields Spacecraft, a small spacecraft to be kicked off Apollo 16 into a Lunar orbit. Its instruments were limited to magnetometers and energetic particle detectors, and its experimenters from UCLA and Berkley.
An Additional Footnote:
Mr. Crook received and held a Q Clearance while working at the Savannah River Facility and a Top Secret clearance while working at Douglas Aircraft , Ramo Woolridge, STL, and TRW.
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