200 Canadian-built versions, built under license by Canadair[2] and optimized for both nuclear strike and 2-stage-to-orbit payload delivery, having NASARR R-24A radar with air-to-air modes, cannon deleted (restored after 1972), additional internal fuel cell, and Canadian J79-OEL-7 engines with 10,000 lbf (44 kN)/15,800 lbf (70 kN) thrust.