The Progress M would make retrofire over Africa, a delta-V of 150 m/s at 350 km altitude. The VBK would separate from the Progress at an altitude of 110 to 130 km, then re-enter separately over Soviet territory. In practice the VBK had a rather poor recovery record, and was felt to take up too much valuable payload space and mass within the Progress.
Landing accuracy was plus-minus 125 km along the orbital trace, and plus-minus 15 km to either side of the orbital trace. At an altitude of 11 to 17 km, a drogue parachute would deploy, a chaff cloud would be jettisoned, and the homing beacon would begin transmitting. The main parachute would deploy at 3 to 4.5 km altitude, allowing the capsule to drift down at 8 m/s to a landing on the steppes. It was anticipated it would take only 3 hours between separation of the Progress and receipt of the payload at the cosmodrome.
AKA: Vozbrashchaemaya ballisticheskaya kapsula.
Gross mass: 350 kg (770 lb).
Payload: 150 kg (330 lb).
Height: 1.47 m (4.82 ft).
Diameter: 0.78 m (2.55 ft).