Sweden's first satellite, Viking, was originally initiated as a means of providing experience in satellite system development and management. The mission's scientific goal was to continue the work of a series of successful sounding rockets by investigating the interaction of the solar wind with the earth's magnetosphere and the behaviour of the resulting aurora borealis. The vehicle's instruments returned a large quantity of data, and completely recorded the full cycle of auroral activity. The total project cost was approximately 20 million US dollars ($FY'86). Spacecraft: Based on the USAF Small Scientific Satellites and NASA's Atmospheric Explorers. Spin stabilised at 3 rpm with torque rods. S-band downlink at 49.6 kbit/s data rate. Power from solar cells on spacecraft body totalling 2.2 square meters, providing 80 W average power. No onboard data storage. Payload: V-1: Electric field - measured electric field. Experiment included 4 40m wire booms and two 4m rigid booms. V-2: Magnetic field - measured magnetic field using a 3-axis fluxgate magnetometer mounted on a 2m boom. V-3: Hot plasma and energetic particles - measured several different energy ranges with 7 different sensors. V-4L: Low frequency waves - Used 2 of the V-1 wire booms plus a magnetic coil antenna on a 2m rigid boom to measure electromagnetic waves between 0 - 15 kHz. V-4H: High frequency waves - Used same sensors as V-4L to measure waves between 10 - 500 kHz. V-5: UV auroral imagers - imaged the Earth's aurora at UV frequencies between 1235A - 1600A and 1340A - 1800A.
Design Life: 8 months. Total Length: 0.5 m. Maximum Diameter: 1.9 m. Total Mass: 538 kg.
Studied magnetic, electric, UV properties of auroral regions. Scientific satellite for the investigation of space plasma physics in the part of the magnetosphere close to the Earth, particularly in connection with the auroral phenomena. The nominal mission period is eight months but an extension can be envisaged. ST /SG/SER.E/167: The satellite Viking has ceased to function on 12 May 1987 due to a gradual degradation of its electrical power supply system. The satellite remains, however, in Earth orbit.