Waxwing was a "spherical" solid rocket motor designed by PERME and built by Bristol Aerojet. Waxwing was an apogee kick motor to be used in the upper stages of theBlack Arrow Launcher to inject satellites into orbit. The photograph at bottom right shows the propellant with its "Star" profile to improve combustion. Solid Rocket Motors usually have some kind of internal profile to aid combustion, but altering the composition can also vary the power of the motor.
A further use of the Waxwing was to increase the velocity of test re-entry vehicles onBlack Knight during tests for the Blue Streak MRBM.