NSSDCA ID: 1992-064A-05
Mission Name: FrejaThe experiment carried a number of sensors, all mounted in the spin plane. Three pairs of 6 cm diameter spherical probes (P1-P6) were mounted at the end of 15 or 7.5 meter wire booms, each probe carrying its preamps also. P1 and P2 are for electric field measurement only, and the rest were switchable between field (voltage) and plasma (current) modes. P1 and P2 were used as HF sensors, in addition to a dedicated pair of 2.5 cm diameter probes mounted on 0.6 meter booms. One of these shorter booms also carried a search coil magnetometer, with one coil parallel to spin axis and the remaining in the spin plane (i.e, one radial and another tangential in the spin plane). Finally, the other shorter boom also carried a cylindrical Langmuir probe, CYLP; the axis of the cylinder pointed to the sun along the spin axis, to minimize photoelectron emission. The sensitivities and frequency coverage of the different sensors were as follows. (1) HF:0.000100 - 0.6 V, 100 kHz-4.0MHz; 0.000002-0.025 V, 20 kHz-1.0 MHz. (2) MF/LF E-field:0.000004 - 1.0 V, 1.0 Hz - 10.0 Hz. (3) MF/LF B-field: 10 micronano Tesla/SQRT(Hz), 30 Hz-10 kHz. (4) Plasma density fluctuations, (Delta N)/N: 0.01% to 50%, 1.0 Hz-1.5 kHz. (5) Temperature fluctuations, (Delta T)/T: TBD, 1.0 Hz-1.5 kHz. (6) Plasma density: N = 1.0 - 60,000 /cc, 0.0 Hz-40 Hz. (7) Electron Temperature: TBD, 0.0 Hz - 40 Hz. Telemetry rate constraints made it difficult to transmit all sampled data; typically only 0.01% of the HF samples, 1.6% of MF samples, and 18.8% of the LF samples could be telemetered, though special situations enabled enhanced telemetering allocations. The instrument is inoperative since 20 June 1995.
Mass: 8.27 kg
Power (avg): 10.6 W
Bit rate (avg): 75.776 kbps
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Alv A. Egeland | Co-Investigator | University of Olso | alv.egeland@fys.uio.no |
Dr. Michael C. Kelley | Co-Investigator | Cornell University | mikek@ee.cornell.edu |
Dr. Carl O. Bostrom | Co-Investigator | Swedish Institute for Space Physics | |
Dr. Eigil Ungstrup | Co-Investigator | Danish Space Research Institute | eu@osiris.gfy.ku.dk |
Dr. Gerhard Haerendel | Co-Investigator | Max-Planck-Institut fur Extraterrestrische Physik | hae@mpe.mpg.de |
Dr. Jan A. Holtet | Co-Investigator | University of Olso | j.a.holtet@fys.uio.no |
Dr. Georg Gustafsson | Co-Investigator | Swedish Institute for Space Physics | georg.gustafsson@ifru.se |
Dr. Paul M. Kintner | Co-Investigator | Cornell University | paul@ece.cornell.edu |
Mr. Gunnar Holmgren | Co-Investigator | Swedish Institute for Space Physics | gunnar.holmgren@angstrom.uu.se |
Dr. Alain Roux | Co-Investigator | Centre National d'Etudes des Telecommunications | alain.roux@cetp.ipsl.fr |
Dr. Herve de Feraudy | Co-Investigator | CNRS-Centre de Recherches en Physique de l'Environment Terrestre et Pl | herve.deferaudy@cetp.ipsl.fr |
Dr. Kristof Stasiewicz | Co-Investigator | Swedish Institute for Space Physics | |
Dr. Hannu Koskinen | Co-Investigator | Finnish Meteorological Institute | hannu.koskinen@fmi.fi |
Mr. Mats Andre | Co-Investigator | Swedish Institute for Space Physics | |
Mr. Bengt Holback | Principal Investigator | Swedish Institute for Space Physics | bengt.holback@irfu.se |