Single stage. Launched 7 February 1961 at 22:16. Apogee 427 miles.
BK13 was a single-stage vehicle with a double cone eroding head similar to BK05 and BK06 except for the substitution of a low-power telemetry beacon plus a tape recorder in place of the normal telemetry sender (BK05) or tape recorder (BK06), the use of a cine camera for filming the head wake during reentry, and the deletion of the recovery parachute system. As in BK07, further measurements were made in the motor bay to investigate base heating and pressures.
Propulsion was good and a re-entry velocity of 10,870 ft/second was achieved at 200,000 ft. The flaps over the base bleed holes opened before take-off and closed later as in BK07. The kerosene level sensor and HTP probes worked and
propellant usage in flight was determined. The head separation, turnover and spin systems were faultless, as were the pyrotechnic flashes on re-entry.
Unfortunately, due to an incorrect setting of the switch, the tape recorder in the head started too soon and the tape had run out before re-entry; for the same reason the camera in the head did not record the re-entry wake. The durestos nose cone and materials specimens were recovered and erosion measurements were made. The electronic flashes were observed clearly but the tracking lamps were not seen.