Optical Measurements on Telstar to Determine the Orientation of the Spin Axis, and the Spin Rate

Metadata

Publisher: SMPTE — White Plains, NY, USA
Doc Type: Journal Article
Content Type: Original Research
Abbreviated Title: J SMPTE
Volume: 72, No. 6, pp. 462–484
Abstract: One plane mirror and two faceted mirrors were fitted to Telstar. A photoelectric telescope was mounted on a radar antenna pedestal. Appropriate recording gear was built. The 12-in. aperture Cassegrain photoelectric telescope could be pointed at the satellite directly from prediction tapes, and the pointing accuracy could on occasion be improved by homing on the microwave beacon on the satellite or by applying corrections from visual observation through other telescopes with apertures of up to 6 in. It has been possible to detect the flashes of sunlight reflected from the mirrors on Telstar at slant ranges up to 3,700 miles. Directly from pairs of these observations, or by combining this information with telemetry data from the solar sensors on the satellite, it has been possible to determine the orientation of the spin axis of Telstar and to examine how this is moving in time. This normal precession of the spin axis is due mainly to the interaction of the residual magnetic moment of the satellite with the magnetic field of the earth. It was also possible to study how the spin axis moved when the torque coil was operated. Measurements have been made of the spin rate of the satellite and of its rate of decay. The spin rate will drop to 1/10 of its initial value in about 750 days. Photographs of the glints have been taken, and a study is now being made of the feasibility of combining precise photoelectric observation of the time of the flashes with high-precision photographic observation of the instantaneous position of the satellite relative to the fixed star background.
Publication Date: 1963-06-01
DOI: 10.5594/J07307
ISSN: Print: 0361-4573
Link: https://doi.org/10.5594/J07307
Author(s): J. S. Courtney-PrattBell Telephone Laboratories, Inc., Murray Hill, N.J.
J. H. HettHett Associates, Inc., 24 Burton Pl., Cresskill, N.J.
J. W. McLaughlinBell Telephone Laboratories.
Copyright: © 1963 Society of Motion Picture and Television Engineers, Inc.

Bibliographic Reference(s)

1. Bangert J. T. Harkless E. T. Engelbrecht R. S. Sperry R. V. Walsh E. J. , “The spacecraft antennas,” Bell Svs. Tech. J. , in press. See also “Project Telstar: communications experiment,” Jour. SMPTE, 72 : 91–96, Feb. 1963 . EXTERNAL
10. Dole S. H. , “Visual detection of light sources on or near the moon,” The Rand Corporation , Research Memorandum No. RM1900, Astia Document No. AD133032, May 27 1957 . EXTERNAL
11. Koomen M. J. , “Visibility of stars at high altitude in daylight,” J. Opt. Soc. Am. 49 : 626 – 629 , 1959 . EXTERNAL
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14. Henize K. G. , “The Baker-Nunn Satellite Tracking Camera,” Sky and Telescope , 16 : 108 – 111 , 1957 . EXTERNAL
2. Hill D. W. , “Optical attitude determination for Telstar,” Bell Sys. Tech. J. , in press. EXTERNAL
3. Thomas L. C. , Bell Sys. Tech. J. , in press. EXTERNAL
4. Herriott D. R. , “Polyhedral satellite for more accurate measurement of orbit data of earth satellites,” J. Opt. Soc. Am. , 48 : 667 – 668 , 1958 . EXTERNAL
5. Wilson R. H. Jr. , “Theory of a polyhedral heliotrope on an artificial satellite,” Aslronomische Nachrichten , 284 : 79 – 82 , 1957 ; and “Optical and electronic tracking,” Monograph No. 4, American Geophysical Union, 67–78, 1959 . EXTERNAL
6. Klahn R. Norton J. A. Githens J. A. , “Antenna steering system,” Bell Sys. Tech. J. , 40 : 1207 – 1225 , 1961 . EXTERNAL
7. Jakes W. C. , “Participation of the Holmdel Station in Project Telstar,” Bell Sys. Tech. J. , in press. EXTERNAL
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J. S. Courtney-Pratt, J. H. Hett, and J. W. McLaughlin; Optical Measurements on Telstar to Determine the Orientation of the Spin Axis, and the Spin Rate, Journal of the SMPTE ( Volume: 72, Issue: 6, June 1963); SMPTE, 1963. Available at https://doi.org/10.5594/J07307

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J. S. Courtney-Pratt, J. H. Hett, and J. W. McLaughlin; Optical Measurements on Telstar to Determine the Orientation of the Spin Axis, and the Spin Rate, Journal of the SMPTE ( Volume: 72, Issue: 6, June 1963); SMPTE, 1963. Available at https://doi.org/10.5594/J07307

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<span class="citation">J. S. Courtney-Pratt, J. H. Hett, and J. W. McLaughlin; <cite>Optical Measurements on Telstar to Determine the Orientation of the Spin Axis, and the Spin Rate</cite>, Journal of the SMPTE ( Volume: 72, Issue: 6, June 1963); SMPTE, 1963. Available at <a href="https://doi.org/10.5594/J07307" target="_blank" rel="noopener">https://doi.org/10.5594/J07307</a></span>

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J. S. Courtney-Pratt, J. H. Hett, and J. W. McLaughlin; <cite id="bib-10-5594-j07307">Optical Measurements on Telstar to Determine the Orientation of the Spin Axis, and the Spin Rate</cite>, Journal of the SMPTE ( Volume: 72, Issue: 6, June 1963); SMPTE, 1963
<span class="doi">10.5594/J07307</span>
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Referenced By

Progress Committee Report for 1963 [Active]
Photoinstrumentation and the SMPTE [Active]
Progress Committee Report for 1964 [Active]