The Ariane Passenger PayLoad Experiment (APPLE) was a significant milestone in India's space exploration history. Launched on 19 June 1981, by the Indian Space Research Organisation (ISRO), APPLE was an experimental communication satellite equipped with a C-Band transponder. The launch was conducted using Ariane, a launch vehicle developed by the European Space Agency (ESA), and took place from the Centre Spatial Guyanais near Kourou in French Guiana.
Key Points About APPLE:
Historical Significance:
- APPLE was India's first three-axis stabilized geostationary experimental satellite, marking a major advancement in the nation's satellite technology capabilities.
- The successful launch and operation of APPLE laid the groundwork for subsequent Indian communication satellites and contributed significantly to the country's space communication infrastructure.
Technical Features:
- The satellite featured a C-Band transponder, which is critical for communication applications such as television broadcasting, satellite radio, and data transmission.
- It incorporated innovative technologies, including a cylindrical structure and a zero-gravity fuel system.
Launch and Orbit:
- APPLE was launched aboard an Ariane-1 rocket, a testament to the collaboration between ISRO and ESA.
- The satellite was placed into a geostationary orbit, which allows it to remain in a fixed position relative to the Earth, providing consistent communication coverage.
Mission Objectives:
- The primary objective of APPLE was to test and demonstrate the feasibility of satellite-based communication for India.
- The satellite also aimed to provide practical experience in the design, fabrication, and operation of communication satellites.
Legacy and Impact:
- APPLE's success paved the way for the development of India’s domestic communication satellite program, leading to the launch of more advanced satellites like the INSAT series.
- It also enhanced India's credibility and capability in space technology on the global stage.
The launch of APPLE on 19 June 1981, represents a landmark achievement for ISRO and highlights the progress and potential of India's space endeavors. It stands as a symbol of technological innovation and international cooperation in the field of space exploration.
Source:https://en.wikipedia.org/wiki/Ariane_Passenger_Payload_Experiment
