From NASA SOUNDING ROCKETS, 1958-1968 - A Historical Summary, NASA SP-4401, 1971, by William R. Corliss
The most interesting addition to the NASA "stable" during the 1965- 1968 period was the Black Brant IV, a rocket built by Bristol Aerospace, Ltd., in Winnipeg. There was some controversy within Goddard regarding the desirability of purchasing a rocket from a foreign country when many American manufacturers build a large variety of sounding rockets. According to Karl Medrow, Chief of Goddard's Sounding Rocket Branch,80 the Black Brant had three positive features that led to its selection:
1. The Black Brants were operational with performance that no American manufacturer could match with off-the-shelf vehicles. (Note: NASA paid only for a propellant change in the Black Brant to improve performance. The U.S. Air Force also contributed financially to the development of the Black Brant series.)
2. The Black Brant used no military hardware and could thus be fired from foreign countries.
3. The Black Brant represented the cheapest way to get the job done.
By the end of 1968, NASA had fired two Black Brant IVs: one with a Canadian payload from Wallops Island on May 7, 1968, and a second from Brazil with a radiation payload provided by the Manned Spacecraft Center, on June 11,1968.
Payload: 18 kg (39 lb) to a 1000 km altitude.
Gross mass: 1,356 kg (2,989 lb).
Payload: 18 kg (39 lb).
Height: 11.06 m (36.28 ft).
Diameter: 0.44 m (1.44 ft).
Thrust: 111.00 kN (24,953 lbf).
Apogee: 1,000 km (600 mi).