Conference 7.286::space

867.0. "Sweden's FREJA Satellite" by VERGA::KLAES (Quo vadimus?) Wed Sep 15 1993 16:34

Article: 71669
Newsgroups: sci.space
From: [email protected] (Goran Olsson, Plasma Physics, KTH)
Subject: Re: Freja Info Needed
Sender: [email protected]
Organization: Plasma Physics, KTH, Stockholm, Sweden
Date: Fri, 3 Sep 1993 10:31:20 GMT
 
Brief Freja Facts:
 
Freja, named after the Nordic goddess of fertility, was launched on October
6th, 1992 by the Chinese launcher "Long March 2C" from Jiuquan in the Gobi
desert, piggybacked on a Chinese satellite. It is Sweden's third satellite.
 
Freja is a small satellite with a launch mass of 256 kilograms. Onboard are
seven experiments, aimed at studying magnetosperic phenomena in relation to
auroral light. The orbit inclination is 63 deg, perigee 601 km and apogee
1756 km. Apogee occurs close to the northern apex. The orbit time is 108
minutes.
 
The Freja project is managed by the Swedish Space Corporation, Stockholm.
Subcontractor for the assembly and testing was the FFV-Aerotech company
(defense industry). The cost excluding experiments amounts to 100 million
kronor (8 kr = 1 US$). Add roughly 50 Mkr for the experiments.
At NASA that would buy just the paperwork to start a project. ;-)
 
The Freja experiments:
 
F1      E-Field          Alfven Laboratory, KTH, Stockholm
F2      B-Field          APL, John Hopkins Univ., Laurel, MD, USA
F3C     Cold Plasma      National Research Council, Ottawa, Canada
F3H     Hot Plasma       Swedish Institute of Space Physics, Kiruna
F4      Waves & Density                  -"-              , Uppsala
F5      UV Imager        Univ. of Calgary, Canada
F6 & F7 e- spectrometer, Max Planck-Institut fuer Extraterrestrische
        Electron Beam    Physik, Garching, Germany
 
Ground stations:
Esrange, Kiruna, Sweden, Control & telemetry
Prince Albert, Saskatchewan, Canada, Telemetry
Syowa, Antarctica (South of the Indian Ocean) Occasional telemetry
 
Freja passes at Esrange last around 20 minutes, 6-7 per day. Downlink
frequency is 2208.1629 MHz, and telemetry rate is 262 kbit/s, optionally
524 kbit/s. Uplink is in the 450 MHz band, and data rate is 1200 bits/s.
 
In addition to the regular downlink there is also an experimental low speed
link that is operated occasionally, relaying housekeeping data. Tabletop
equipment is sufficient for receiving this. DX opportunity!  The F2 group
at JHU, APL, Laurel, MD, have been participating in the operation. For
information on future transmissions over the US east coast, as well as
frequency, data formats and so on, contact APL or Sven Grahn at the Swedish
Space Corporation. E-mail: [email protected]
 
The F1 experiment has six spherical (6 cm dia) probes on 10 meter  wire
booms, extended by the spinning of the satellite. (10 rpm)  The probes
connect to high impedance amplifiers that allow an adjustable bias current
to be applied to the input. The signals are sampled at 768 s/sec and
digitized to 16-bit quantities. Range is +-1.8 V/m. Other modes are
available, burst: 6144 s/sec and overview, 8 s/sec, where data is collected
to a local memory for later transmission.
 
Freja is operating successfully, and loads of interesting data are being
collected.
 
A 260 page book describing Freja in detail has recently been issued.
The circulation is limited, and I don't know if copies are available.
Those interested should make requests to Rickard Lundin, IRF, Kiruna.
(Freja Project Scientist) E-mail: [email protected]
 
Contact me if you want a .GIF image of Freja.
 
========================================================================
 Goran Olsson, Plasma Physics, Alfven Laboratory, KTH, Stockholm, Sweden
      F1 - The Electric Field Experiment on the FREJA satellite
                         [email protected]
========================================================================