The first two launch vehicles were used as 'proving rounds': launches which lacked any payload in order to test and validate the design of the rocket itself. The third launch of the Black Knight was the first to carry an actual payload in the form of a re-entry vehicle, which was present for the purpose of testing the properties of the re-entry body's chosen design. All the re-entry firings deliberately took place on clear moonless nights, so that the luminous wake of the re-entry body could be observed photographically.