APPLE of India

APPLE on a Bullock Cart. This image has become a symbol of Indian innovative thinking. The story behind this is that APPLE was to be tested for Telemetry, Tracking, and Command link. It required an antenna test to be conducted in an open field. Since the instruments were very sensitive, they required a non-magnetic environment. Doing the test outside India would have cost them time and money. The solution was thus found in five hours and an Ox cart was hired for 150 rupees, and tests were conducted without further delay.

In 1968, CNES, the young French Space Agency proposed the European Space Research Organization (ESRO) to Europeanize its space meteorology. This was the beginning of the Meteosat program. Meteosat was the European meteorological program in GEO (Geostationary Orbit) that was initiated in 1972 by ESRO (European Space Research Organization).

Upon the approval of the projecr in 1972, Meteosat-1 program was funded by eight member states of ESRO (Belgium, Denmark, France, Italy, Germany, the United Kingdom, Sweden, and Switzerland). Meteosat-1 launched on November 23, 1977, became the first European meteorological geosynchronous satellite.

While the work on Meteosat-1 was being carried out, European Space Agency (ESA), ESRO’s successor established in 1975, conceived an idea of Ariane Passenger PayLoad Experiment (APPLE) in the same year. It was based on a free launch opportunity on the Ariane launch vehicle that was under development by ESA in parallel. 

APPLE being tested in India. Image Credit: ISRO

Among seventy-two proposals sent to ESA, the Indian proposal was approved in 1976. It was also because ISRO was collaborating in the development of liquid propulsion engine Viking for Ariane launchers. Although this was not in the plan for ISRO, yet it proved to be a leap of faith for them. 

APPLE was to be designed and built as a sandwich passenger-carrying Meteosat on the top and Capsule Ariane Technologique below. ISRO was working assiduously to make this project a success. Engineers were working during the night at the Indian Institute of Science (Bangalore), Indian Institute of Technology – Madras (Madras, now Chennai), and Tata Institute of Fundamental Research in Bombay (now Mumbai). Hardware was realized with the help of Hindustan Aeronautics Limited, Electronics Corporation of India Limited, and Bharat Electronics. It was becoming a task to set up a testing facility and mission control center. It went through though at Sriharikota. In Ahmedabad, the Space Application Center was trying to build the payload and antenna testing facility. Despite several difficulties that were faced by India the standards were met with accuracy. 

APPLE in the testing facility in India. Image Credit: ISRO

ISRO wanted to gain experience in designing, manufacturing, and testing a tri-axially stabilized communication satellite. There were about two and a half thousand people involved. It included engineers, scientists, technicians, and administrators. It is noteworthy that the average age of the team was 27 years and the project director Vasagam was 37 years old at the time.

Once manufactured in India, the solid apogee motors were sent to France, and were moved to Kourou late. Indian-made hydrazine, to be used for in-space spacecraft propulsion, was sent to Kourou by ship. R M Vasagam, the project director for APPLE remembers, “Air India had been our carrier but at a critical moment we were facing the difficulty of getting the chartered aircraft to come to Toulouse to carry the spacecraft to Kourou owing to violation of Lome Convention of 1975. Kourou being French overseas territory, we had to engage Air France!” The budget was a concern but it turned out to be cheaper.

Structure of ISRO during APPLE project. Courtesy: Historical Archives of the European Union (Doc: ESA-4780)

He wrote, “The successful functioning of the transponder was tested using a live dance program signal sent to and received from the satellite. The time delay for nearly 80000 km (to and fro distance to satellite) is about 270 milliseconds. APPLE transponder also transmitted Rabindranath Tagore’s dance drama Chitrangada. While characterizing the end-to-end performance of the APPLE communication link, it was our way of blending the best of the East and West!” APPLE became a symbol of change; it succeeded in touching people’s lives.

The Indian Team. Dr. Man Mohan Singh was a member of the Space Commission during the APPLE project. He later became the 13th Prime Minister of India

Launched on 19 June 1981, then Prime Minister Mrs. Indira Gandhi dedicated the satellite to the nation on 13 August 1981 calling APPLE the dawn of India’s satellite communication era. Satish Dhawan was at Space Application Centre where he introduced the team to the PM through a two-way video conference. Mrs. Gandhi was present at the New Delhi station. Her Independence Day address on 15 August 1981 was carried live by APPLE.

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