References 1 Brace, L. EL, Spencer, N. W., and Dalgarno, A., Detailed Behavior of the Mid Latitude Ionosphere from the Explorer XVII Satellite, Planetary and Space Science, Vol. 13, 1965, pp. 647-666. 2 Brace, L. H., Reddy, B. M., and Mayr, H. G., Global Behavior of the Ionosphere at 1000 km Altitude, Journal of Geophysical Research, Vol. 72, 1967, pp. 265-284. 3 Dalgarno, A., McElroy, A. M. B., and Walker, J. C. G., The Diurnal Variation of Ionospheric Temperatures, ' Planetary and Space Science, Vol. 15, 1967, pp. 331-345. 4 Hanson, W. B., McKibbin, D. C., and Sharp, G. W., Some Ionospheric Measurements with Borne Ion-Traps, Journal of Geophysical Research, Vol. 69, 1964, pp. 2747-2763. 5 Kmg-Hele, D. G., The Rotational Speed of the Upper Atmosphere Determined from Changes in Orbits, Note Space 59, Feb. 1964, Royal Aircraft Establishment. 6 Mott-Smith, H. M. and Langmuir, M. S., The Theory of Collectors in Gaseous Discharge, Physical Review, Vol. 28, 1926, pp. 727-763. 7 Sagalyn, R. C., Smiddy, M., and Bhargava, Y. N., Satellite Measurements of the Diurnal Variation of Temperature in the F Region, Space Research V, North-Holland, Amsterdam, Netherlands, 1965, pp. 189-206. 8 CIRA, COSPAR International Reference Atmosphere, NorthHolland, Amsterdam, Netherlands, 1965. 9 Sagalyn, R. C. and Smiddy, M., Electron Density and Temperature Measurements in the Ionosphere, Sounding Rocket Research Technique Instrumentation Manual No. 9, edited by K. Maeda, Committee on Space Research of the International Council of Scientific Unions, Feb. 1967. 10 Sagalyn, R. C. and Smiddy, M., Positive Ion Sensing System for the Measurement of Spacecraft Pitch and Yaw, Air Force D-10 Experiment, Air Force Surveys in Geophysics No. 201, AFCRL 67-0158, Air Force Cambridge Research Labs., Dec. 1967.