NSSDCA ID: 1969-051A-01
Mission Name: OGO 6The microphone atmospheric neutral density gauge experiment measured the spatial and temporal variations of density in the altitude range from 250 to 700 km. The instrumentation consisted of a thin metal ribbon suspended in a magnetic field looking along the spacecraft's velocity vector and exposed to the moving air stream. The air entering the apparatus was mechanically chopped so that the ribbon was forced to oscillate in the magnetic field, the amplitude of the oscillations being proportional to the applied pressure. The electrical voltage generated by the motion of the ribbon through the magnetic field was amplified and rectified to provide a dc signal for telemetry. From the pressure values and from a knowledge of the velocity of the air stream (effective spacecraft velocity), atmospheric density could be deduced. Once every 2 min, the air flow was stopped for 20 s to establish a zero reference value for inflight calibration. For more details of experiment operation, see G. W. Sharp et al., "Atmospheric density measurements with a satellite-borne microphone gage," J. Geophys. Res., v. 67, n. 4, pp. 1375-1382, April 1962. The experiment was a success, and good data were obtained from launch until the second week in February 1970, when there occurred an unexpected phase shift in the sensor output. The experiment operated in this manner until the spacecraft was deactivated on June 28, 1971.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Mr. T. J. Crowther | Other Investigator | Lockheed Palo Alto | |
Dr. Gerald W. Sharp | Principal Investigator | NASA Headquarters |