Table of Contents

Sciences

GEODESIC probes the plasma

There are four states of matter: solid, liquid, gas and, of course, plasma. You knew that, right? Plasma, makes up most of the matter in the universe. It occurs when an external energy source, such as electromagnetic radiation, frees electrons and ions from binding together. But not all plasma behave in the same way.

Canada has long been interested in gaining a better understanding of the Earth's plasma environment and of other events in the upper ionosphere. These can interfere with radio communications, global positioning systems, ground electrical systems, and low-Earth satellite orbits.

So, on February 26, 2000, a Canadian Black Brant 12 sounding rocket was launched from the Poker Flat Rocket Range in Alaska. It carried an experiment to study fine plasma structures above the Earth's ionosphere. Above the Earth, at 990 km, is a key region in geospace where plasma is subject about equally to the influence of the ionosphere and magnetosphere. The rocket reached this point and brought back approximately 17 minutes of valuable scientific data.

The GEODESIC experiment was selected in 1997 as part of the CSA's Small Payloads Program. GEODESIC stands for “geo-electrodynamics and electro-optical detection of electron and suprathermal ion currents.“ On a very small scale, it studied the physics of plasma right in the atmosphere. This knowledge is important because much of the transfer of energy from electromagnetic fields to individual particles, some of which helps to excite the auroras, also occurs on a very small scale.

The GEODESIC experiment had six scientific instruments. The University of Calgary provided a thermal electron imager and a suprathermal ion imager. The Aerospace Corporation of the U.S. provided an energetic electron and an ion top-hat analyzer. NASA Goddard Space Flight Center provided a three-axis electric field double-probe, while a fluxgate and a search-coil magnetometer were supplied by Magnametrics of Ottawa. Winnipeg's Bristol Aerospace Ltd. builds the Black Brandt rockets and the company was the prime industrial contractor for the experiment. The Principal Investigator for GEODESIC was Professor David Knudsen, Department of Physics and Astronomy at the University of Calgary.