Black Knight - BK07

BK07 was a single stage vehicle with a high drag heat shield head equipped to give separation details, heat transfer data and re-entry dynamics, using telemetry. Extensive instrumentation was put in the motor bay to investigate base heating and pressure distribution. In addition lightly loaded spring flaps were fitted to the pressure bleed holes in the propulsion bay to check the direction of flow through these holes. Their movement was monitored by telemetry. Changes in position of H.T.P. tank baffles were made to check on "H.T.P. slosh" and a kerosene level sensor was included to enable kerosene consumption to be measured.

Propulsion was satisfactory except that towards the end of the burning phase one of the four motors reverted to "cold" thrusting and this resulted in a reduced re-entry velocity. This motor fault was subsequently attributed to a failure of a kerosene feed pipe.

The head was separated from the main body but the additional thrust units in the head, provided to give increased separation, did not operate; nor did the turn over and spin thrust units. However, the head did re-enter nose first, but at large initial incidence; the recovered head shows that impact was on the nose and that there was no re-entry burning on the afterbody. Head telemetry was extremely good and re-entry data was obtained. Complete dynamic analysis of the re-entry head was possible and head temperatures during re-entry were obtained.

Temperatures and pressures in the motor bay were measured. The flaps over the base bleed hole in the motor bay opened at engine light-up and shut (two at 83 seconds and two at 89 seconds) without significant changes in motor bay pressures. There was no significant effect of the new arrangement of baffles in the H.T.P, tank on slosh damping.

The kerosene level sensor worked and the kerosene flow rate was determined. The upper atmosphere experiments, Geiger and scintillation counters and Sporadic E, were switched on correctly just after engine burn-out. The tracking lamps which were fitted for the first time to this vehicle were seen clearly by the guidance telescope operator and the kinetheodolitc operators after engine flame-out until about 200 seconds. The electronic flash unit failed to function.

Number Stages Date local
time Empty
wt [lbs] HTP
[lbs] Kerosene
[lbs} All up
wt [lbs] Burn-out
time [s] Apogee
miles

07 1 25 7 60 21.24 1 600 10 242 1 347 13 371 148.5 330