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Langmuir Probes

NSSDCA ID: 1963-009A-02

Mission Name: AE-A
Principal Investigator:Mr. Larry H. Brace


The Explorer 17 experiment payload included two independent Langmuir probe systems. One of the sensors was used to provide measurements of the positive ion density, and the other measured electron temperature. Each system used a two-element sensor consisting of an outer cylindrical guard electrode 10-cm long which was concentric with an inner collector electrode 0.056 cm in diameter and 23-cm long. The potentials of the electrodes were varied with respect to the satellite shell. The electron temperature probe was swept at a rate of 10 sweeps per second over two different voltage intervals, 0 to 0.75 V and 0 to 1.5 V. The ion density probe was swept from minus 3 to plus 2 V in 2 s. The currents to the collectors were measured and telemetered. The ion concentration and electron temperature could be determined from the current vs voltage information. The experiment operated normally from launch until July 10, 1963, when the spacecraft batteries failed. More details can be found in L. H. Brace et al., Planet. Space Sci., v. 13, n. 7, p. 647, 1965. NSSDC has all the useful data that exist from this investigation.

Alternate Names

  • AE-A/LangmuirProbes


  • Space Physics: Ionospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Dr. Dieter K. Bilitza



NameRoleOriginal AffiliationE-mail
Dr. Nelson W. SpencerOther InvestigatorNASA Goddard Space Flight Center
Mr. Larry H. BracePrincipal InvestigatorNASA Goddard Space Flight Center
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