Viking (satellite)
Encyclopedia
Viking was Sweden
's first satellite
. It was launched on an Ariane 1
rocket as a piggyback payload together with the French
satellite SPOT 1
, on February 22, 1986. Operations ended on May 12, 1987. Viking was used to explore plasma processes in the magnetosphere and the ionosphere.
Space was limited underneath the SPOT 1 satellite, and Viking had to be quite sturdy in order to withstand the stress of launch. The basic shape of the Swedish satellite was a flat octagonal disc, 0.5 metres thick and 1.9 metres across. The mechanical interface of the payload adapter from the Ariane rocket was duplicated on top of Viking. This enabled it to be added to the launch with a minimum of redesign of the SPOT satellite. After SPOT had been released, Viking fired its own rocket engine
and was sent into its proper polar orbit
.
Once in orbit, 4 wire
segments of 40 metre length each were spooled out in a radial direction from the edge of the spinning satellite disc. Also, 2 stiff rods of 4 metre length were extended in the axial direction. A sensor pod was stationed at the end of each of these, forming three orthogonal pairs. Together they could measure the electric field
of the earth in all three dimensions. Stiff booms were also extended for other types of sensors and antennas.
The mission produced a large amount of extremely useful scientific data, and was deemed a great success. An initial discussion of what scientists learned from these measurements, which included "global distribution of magnetosphere-ionosphere interaction; aurora
l morphology and substorm
dynamics; heating and expulsion of ionospheric plasma into the magnetosphere; field aligned acceleration into the ionosphere; and electron and ion wave generation" can be found in the article "Scientific results from the Swedish Viking satellite", 1988 Swedish Inst. of Space Physics, Kiruna. Since then, many other scientific articles have been written using this important data set.
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
's first satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
. It was launched on an Ariane 1
Ariane 1
Ariane 1 is the first version of the Ariane launcher family. Ariane 1 was designed primarily to put two telecommunications satellites at a time into orbit, thus reducing costs. As the size of the satellites grew Ariane 1 gave way to the more powerful Ariane 2 and Ariane 3 launchers.- Vehicle...
rocket as a piggyback payload together with the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
satellite SPOT 1
SPOT (satellites)
SPOT is a high-resolution, optical imaging Earth observation satellite system operating from space. It is run by Spot Image based in Toulouse, France...
, on February 22, 1986. Operations ended on May 12, 1987. Viking was used to explore plasma processes in the magnetosphere and the ionosphere.
Space was limited underneath the SPOT 1 satellite, and Viking had to be quite sturdy in order to withstand the stress of launch. The basic shape of the Swedish satellite was a flat octagonal disc, 0.5 metres thick and 1.9 metres across. The mechanical interface of the payload adapter from the Ariane rocket was duplicated on top of Viking. This enabled it to be added to the launch with a minimum of redesign of the SPOT satellite. After SPOT had been released, Viking fired its own rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
and was sent into its proper polar orbit
Polar orbit
A polar orbit is an orbit in which a satellite passes above or nearly above both poles of the body being orbited on each revolution. It therefore has an inclination of 90 degrees to the equator...
.
Once in orbit, 4 wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
segments of 40 metre length each were spooled out in a radial direction from the edge of the spinning satellite disc. Also, 2 stiff rods of 4 metre length were extended in the axial direction. A sensor pod was stationed at the end of each of these, forming three orthogonal pairs. Together they could measure the electric field
Electric field
In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
of the earth in all three dimensions. Stiff booms were also extended for other types of sensors and antennas.
The mission produced a large amount of extremely useful scientific data, and was deemed a great success. An initial discussion of what scientists learned from these measurements, which included "global distribution of magnetosphere-ionosphere interaction; aurora
Aurora (astronomy)
An aurora is a natural light display in the sky particularly in the high latitude regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere...
l morphology and substorm
Substorm
A substorm, sometimes referred to as a magnetospheric substorm or an auroral substorm, is a brief disturbance in the Earth's magnetosphere that causes energy to be released from the "tail" of the magnetosphere and injected into the high latitude ionosphere. Visually, a substorm is seen as a sudden...
dynamics; heating and expulsion of ionospheric plasma into the magnetosphere; field aligned acceleration into the ionosphere; and electron and ion wave generation" can be found in the article "Scientific results from the Swedish Viking satellite", 1988 Swedish Inst. of Space Physics, Kiruna. Since then, many other scientific articles have been written using this important data set.