NSSDCA ID: 1967-073A-17
Mission Name: OGO 4This experiment was flown to obtain a description of the distribution of the neutral atmospheric density and temperature in the upper thermosphere and exosphere as a function of spatial and temporal changes. In addition, correlations between changes in the atmospheric parameters and variations of solar and magnetic activity were to be studied. A Bayard-Alpert pressure gauge was used as the sensor. This hot filament detector had a helical grid around an axial cylindrical collector. Electrons emitted from one of the three redundant filaments, mounted outside the grid, ionized the neutral particles by collision. The positively charged grid not only accelerated the electrons, but it also repelled the positive ions toward the collector and produced a measurable collector current, which was proportional to the number density of particles inside the gauge. Located in the OPEP, the sensor was scanned about the velocity vector. It was planned that the variation of gauge density during the scanning operation would yield the neutral particle velocity distribution from which atmospheric temperature could be deduced. The data base from this investigation no longer exists.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
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Dr. George P. Newton | Principal Investigator | NASA Headquarters |