The successful launching of APPLE (Airline Passenger Payload Experiment India's first three-axis stabilised experimental communication satellite, using ARIANE launcher, on June 19, 1981, marks an important milestone in India's space programme. By positioning the APPLE Spacecraft in the three-axis stabilised mode in the geostationary orbit at 102'E longitude on July 16, 1981 after carrying out complicated mission manoeuvres, India joined the ranks of nations who have developed their own three-axis stabilised stationary communication satellite.

APPLE, with a launch weight of 673 Kgs. has a cylindrical structure of 1200 mm diameter with an overall height of 1985 mm. The spacecraft was designed and developed at the ISRO Satellite Centre (ISAC) of ISRO at Bangalore. This centre was also responsible for the overall management, the development of spacecraft structure, thermal, TTC, power, control and sensors systems, spacecraft integration, testing, mission planning and launch and operationalisation.

The satellite, after integration and tests at the ISRO Satellite Centre, Bangalore, was transported to Toulouse, France, for compatibility tests with METEOSAT and CAT satellites forming part of the composite ARIANE payload. The satellite was subsequently transported to Kourou, French Guyana, and after conducting final checks was integrated with the ARIANE launcher. After injection into the transfer orbit and separation from ARIANE, APPLE was tracked by a network of ISRO's and ESA's ground stations. The mission control operation were performed from APPLE Mission Control Centre at SHAR, which included the firing of the ABM to place APPLE into a near synchronous orbit, deployment of panels, three-axis stabilisation of the spacecraft and final orbital manoeuvres which resulted in the placement of APPLE in the geosynchronous orbit at 102'E longitude.

The APPLE Utilisation Programme was formally inaugurated by the Prime Minister on August 13, 1981, through a nationwide TV hookup via APPLE. Under APPLE utilisation programme a number of communication experiments are being carried out in cooperation with Posts and Telegraphs, Doordarshan, TIFR and others. APPLE has enabled experimentation in the advanced communications technology and has established expertise in the design, fabrication, launch and complicated post launch mission manoevres for placing and maintaining such a satellite in the geo-stationary orbit.

Indian Posts and Telegraphs Department is happy to issue a commemorative stamp on the first anniversary of the launching of APPLE satellite.

Source : Information Folder issued by Indian Posts & Telegraph Department, Government of India