Payload recovery

On the basis of the float wind conditions observed during sounding ascent prior to the main flight, an advance recovery team is despatched about an hour after launch to a suitable down range position. Once the zero pressure balloon is launched, it is free to drift in the direction of the prevailing wind and there is no control to change the direction of drift. During the flight, the balloon is allowed to drift anywhere within the confines of the operational corridor limits imposed by Director General of Civil Aviation, Govt. of India. However, care is taken to see that the balloon does not drift into thickly populated, hilly, or forest areas, thereby endangering the safe recovery of the scientific payload and accessories after the flight. Monetary reward tags are attached to the payload train to encourage the finders to preserve the equipment, with the assistance of local police until the arrival of the recovery team. As an aerial recovery is not practicable due to the high cost involved, the recovery is carried out only by surface transport.

In order to ensure that the recovery team reaches the payload impact point as quickly as possible, an advance recovery party is sent in a jeep to follow the balloon immediately after it reaches its ceiling altitude. The advance party keeps in constant touch with the base station, and is continuously briefed about the trajectory of the balloon. The advance team keeps following the balloon and in most cases is able to reach the payload impact point within a couple of hours of touchdown. After eaching the payload impact point, the advance party takes care of the instruments and await the arrival of the Main Recovery Team. TIFR Balloon Facility uses 60 feet to 100 feet dia. conventional parachutes, depending on the weight for payload recovery.

The main recovery team leaves the base station after the termination of flight in a truck capable of accommodating the main payload, accessories as well as the recovery team. The main recovery team is asked to proceed to the projected payload impact point obtained from the GPS/Radar Data, or the actual payload impact point itself in case the payload touchdown message is conveyed to the base station by a telephone / telegram before the start of the journey. The main recovery team also keeps in touch with the base station for fresh inputs regarding the payload landing area. In case no information is available, the advance team and the main recovery team conduct searches in the projected area of payload landing till the payload is recovered. The TIFR Balloon Facility recovery crew is well equiped to handle difficult situation and bring the packages to the base for post flight check. So far, the payload recovery rate has been excellent.