On July 22nd 1981, India’s first geo-stationary satellite APPLE started functioning.
The Ariane Passenger PayLoad Experiment (APPLE), an experimental communication satellite was launched by the Indian Space Research Organisation (ISRO) on July 19th 1981, which began functioning on July 22nd of the same year. APPLE was an experimental communications satellite with a C-Band transponder. This satellite was launched by Ariane, a launch vehicle of the European Space Agency in French Guiana. The successful launch of APPLE was a major milestone for India’s space program.
After having successfully placed the APPLE spacecraft in the three axis stabilized mode in the geostationary orbit, India joined the league of nations who had developed their own three axis stabilized stationary communications satellite. APPLE had a launch weight of 673 kgs and a cylindrical structure of 1200 mm diameter and a height of 1985 mm. On July 19th 1981, the satellite was placed at 102 degrees east longitude and proved to be an important landmark in Indian space research.
APPLE was designed and developed at the ISRO Satellite Centre in Bangalore. The centre was also responsible for the management and development of the spacecraft structure, TTC, power, thermal, control and sensor system, testing, mission planning and launch. After being tested at ISRO, APPLE was sent to Tolouse in France so that compatibility tests could be carried out with METEOSAT and CAT satellites, which would be part of the payload.
After tests were carried out in Tolouse, the satellite was transferred to Kourou, French Guiana where final tests were carried out. After this, the satellite was integrated with the Ariane launcher. The mission control was done from the Satish Dhawan Space Centre (SHAR) in Andhra Pradesh.
This satellite was used in many experiments such as the telecast of TV programs and radio shows. Apart from that, APPLE also made possible experimentation in advanced communication technology and brought about competence in matters of design, launch and post-launch maintenance for placing and then maintaining such satellites in the geo-stationary orbit. APPLE remained in space for a little over two years, till altitude controlled fuel depletion and went out of service on September 19th 1983.
The launch of APPLE was a moment of great pride for India and the first anniversary of its launch was marked by the India Postal Service issuing a commemorative stamp in its honour.
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