The disturbed atmospheric conditions that exist at high altitudes were of particular concern to researchers in Canada. At first, knowledge of the upper atmosphere was obtained by deduction from indirect measurement such as spectroscopy of the night sky and aurora or the reflection of radio waves from the ionosphere. A great deal was learned by such methods, but several surprises came about through rocket technology that made direct measurements possible. They provided the only means for conducting experiments at altitudes between the maximum altitudes for balloons and the minimum altitude for satellites. Sounding rockets allowed scientists to conduct investigations at a specific time and place. A sounding rocket follows a parabolic trajectory - it goes up and comes back down, with a flight time of less than 30 minutes. The rocket motor uses its fuel then separates from the payload and falls back to Earth. The payload continues farther in space before dropping back to earth.
The region between 35 km and 300 km is the region usually explored by sounding rockets. This region contains most of the aurora and the reflecting layers of the ionosphere. It also includes the absorbing region in the lower ionosphere, the study of which was vital to radio communication.
The Churchill Rocket Range
As part of the International Geophysical Year (IGY), July 1957 to December 1958, American scientists wished to use rockets to probe the atmosphere near the auroral zone for comparison with data they had collected at White Sands, New Mexico. Sites were being considered in Alaska, Canada and Greenland. Churchill, Manitoba looked most promising. It was ideal in being located right in the auroral zone and, in addition, it was accessible by rail and sea. As well, the Defence Research Northern Laboratory and Fort Churchill Army Camp were already located there.
In 1954, a party of American scientists and army personnel embarked on an inspection tour. En route to Churchill, the party stopped at DRTE near Ottawa to confer with Chief Superintendent Frank Davies who at that time was also the Chairman of the National Committee of the IGY.
Facilities at Churchill were found to be generally more adequate than had been anticipated; however, serious deficiencies noted were the lack of reliable telephone service to the south and reliable weather forecasts. The Americans were alerted to the dangers of “windchill”, an index new to them. The general conclusion was that, with strict observance of rules for survival in the severe climate, a successful rocket program could be carried out at Churchill. The Defence Research Board was enthusiastic about the American concept and plans were made for launch facilities to be installed by the American army. In fact, the first rockets launched were Nike-Ajax ground-to-air missiles fired independently by the Canadian Army as part of cold weather trials in February-March 1955 and repeated in 1956.
Construction of the Churchill launch facilities began in 1956 and was completed in 1957. During the International Geophysical Year, about 95 Aerobee and Nike-Cajun class rockets were launched. In December 1958, the IGY program ended and the Churchill range was closed.
However, data obtained during the IGY proved very interesting to upper atmospheric scientists. This led to a request for the range to be re-opened and it was re-opened in August 1959. Although responsibility for operation rested with the US army, a number of Canadian and American groups had access to it. When the United States decided that activities at the Churchill Research Range would be phased out by June 1970, the National Research Council continued the operations of the range on a reduced basis in support of the Canadian Upper Atmosphere Research Program. For 25 years, Canada had an active rocket program with its main focus at Churchill. The program was finally terminated in 1984.
From the early 1950s, scientists at the Canadian Armament Research and Development Establishment (CARDE) had been investigating solid rocket propellants for military purposes. The original Propulsion Test Vehicle was a relatively heavy rocket, since it was designed to stand up to the use of a wide range of engine burning times, propellant loadings and launch angles associated with fuel development. The test vehicle was renamed Black Brant I after a small dark goose that nests along the Arctic coast. Noting the increased interest in rockets as scientific tools, CARDE staff embarked on a program that led to a family of Black Brants for upper atmospheric research. The first Black Brant I was launched at Churchill in September 1959. The rocket technology was later transferred for commercial production to the Winnipeg firm that later became Bristol Aerospace Limited. The Black Brant series of rockets was a highly successful family that provided Canadian scientists with a broad range of possibilities for atmospheric probing, and to Canada a commercial product that gained respect and impressive sales in a tough international market.
Studies at DRTE and CRC
DRTE became interested in sounding rockets as a means to greater understanding of the physics of the ionosphere with a view to improving radio communications. The first two payloads built at DRTE were launched in September, 1959, aboard Aerobee rockets provided by the Americans. The DRTE project was managed by Walter Heikkila. The rockets carried an experiment designed to determine the electron density of the ionosphere for comparison with ground-based measurements. In addition, cosmic-ray detectors were provided by Drs. D.C. Rose and I.B. McDiarmid of NRCC to determine charged particle intensities. The successful co-operation between the USA and Canada during this early rocket program established protocols that were used in the later satellite programs.
The following year, DRTE designed payloads for three Black Brant rockets built at CARDE. Three experiments were carried out with each rocket: (a) radio wave signal strength variation with height from the ground, using transmissions from DRTE, (b) energetic particle measurements (NRC), and (c) positive ion measurements (University College, London). Two of the firings penetrated auroral absorption layers.
For scientists at DRTE, the Black Brant sounding rockets proved to be a valuable tool to measure parameters other than those gained from ground experiments. The rockets were particularly helpful in obtaining information on the absorbing region in the lower ionosphere that interrupted high frequency radio communication but was difficult to study from the ground.
Over the next 25 years, more than 50 rockets carried DRTE/CRC experiments. A variety of experiments was devised and the payloads became more sophisticated. Some payloads were equipped with parachutes to provide a soft landing so that instruments and/or data might be recovered.
Rapid advances in knowledge were made using rockets in conjunction with satellites and ground-based measurements. In 1967and 1968 launches were made from Resolute Bay as well as Churchill.
Special expeditions were organized to focus on specific phenomena. Transportable launchers were installed at East Quoddy, Nova Scotia to study ionospheric effects of the solar eclipses of March 7, 1970 and July 20, 1972. Four rockets were launched during each eclipse. These experiments were carried out by a team including Jack Belrose, and Len Bodé. During 1966-70, VLF receivers and other experiments were carried aboard high altitude (800-1000 km) rockets - the NASA Javelin and the Black Brant IV - at Wallops Island (USA) and Fort Churchill. These experiments were designed by Ron Barrington, Frank Palmer, Bill Rolfe and Roger Charron. Don McEwan was also responsible for development of rocket experiments. As the rocket program grew, NRCC took over management of all aspects including engineering and integration of rocket payloads. The program was finally phased out in 1984.
Barrington, R.E. "Canadian Space Activities in the Past Quarter Century." Canadian Aeronautics and Space Journal. vol 25, no. 2, 1979.
Chapman, J., Heikkila, W., and Brown, R. "Two High Altitude Rocket Experiments." Ottawa; DRTE, 1960.
Jelly, D.H. “Canada: 25 Years in Space”, published by Polyscience Publications Inc. and the National Museum of Science and Technology, 1988.
Waters, William. Space and Upper Atmosphere Research in Canada: Balloons, Rockets and Satellites. Ottawa; National Research Council, January 1970.