Indian scientists develop an ambitious space program

India entered the space age in the 1960s, when it began to launch rockets from the Thumba Equatorial Rocket Launching station near Trivandrum, the capital of the southern state of Kerala. Now, after more than a thousand Thumba launchings, and with Indian satellites circling the globe, the country is on the verge of making major use of near-Earth space.

Besides providing telecommunications, Indian satellites soon will scan the resources in the far-flung corners of the country. They will study geological structures. And they will be used to track the weather. Indeed, the Indian-designed (INSAT) satellites are the first in the world to combine telecommunications, weather observing, and direct TV broadcasting in a single vehicle. What is more, India is looking forward to the flight of its first cosmonaut on board the Soviet Salyut-7 space station next year.

Thumba soon proved inadequate for India's needs and space ambitions. The Sriharikota range, better known as SHAR or arrow, was built on a spindle-shaped island in a desolate stretch of the backwaters of the east-coast state of Andhra Pradesh. Since 1969, when the site was selected for a satellite-launching station, SHAR has become a gigantic complex of technical facilities. It has also developed a large township for the 1,500 people working there.

Thus, even though India has had to rely on other nations to launch many of its satellites, it is working to become self-sufficient in launch capability.

Dr. Vikram Sarabhai, an industrialist who pioneered India's space program, was the man whose vision lives on in this and other centers of the Indian Space Research Organization. Years ago he proclaimed: ''We're convinced that, if we're to play a meaningful role nationally and in the community of nations, we must be second to none in the application of advanced technologies to the real problems of man and society which we find in our country.''

One of the earliest experiments in the 1970s involved broadcasting of educational TV programs in the Satellite Instructional Television Experiment. The United States gave India partial use of its ATS (Applications Technology Satellite) vehicle for the purpose. Under this program, villages where people had never seen a motion picture could be reached directly through community TV sets.

This was also about the time when the first India-made satellite, Aryabhata, was launched from a Soviet cosmodrome. Later, the Soviets launched India's Bhaskara-I, which carried out remote sensing of India's natural resources and mapped its geography, and Bhaskara-II, which extended and continued that work.

India's rocketry is not nearly as advanced as its technology for building and controlling satellites. Last year, the Ariane launcher of the European Space Agency launched India's APPLE (Ariane Passenger Payload Experiment) satellite from French Guyana in yet another collaborative effort.

However, India is developing a launch capability of its own. Apart from the launchings of APPLE on June 19, 1981, and of Bhaskara-II on Nov. 20, 1981, the major Indian space event last year was the third test flight of the solid-fueled , four-stage SLV-3 rocket. After an initial failure in 1979 and a successful test flight in July 1980, this third test was only partly successful. Launched from SHAR on May 31, 1981, it placed the 38-kilogram Rohini satellite into a lower orbit than planned. Though originally expected to last 90 days, the satellite re-entered the atmosphere after only nine days.

At this writing, Indian launch crews were scheduled to try again in September when the SLV-3 was to orbit a 42-kilogram payload.

What has excited Indian space scientists most so far this year has been the launching last April of the multipurpose Indian National Satellite (INSAT-IA). Made to Indian specifications by Ford Aerospace Corporation and launched by the US National Aeronautics and Space Administration, it combines telecommunications , weather observing, and direct broadcast TV in a single vehicle.

Here again, India has met with mixed success. Although scientists and space engineers still expect to learn much from the satellite, its solar sail, which provides electrical power, failed to deploy.

The satellite alone costs $62,400,000; the entire project costs $187,200,000 with another $88,400,000 earmarked for television coverage through INSAT. Instead of lasting for seven years, INSAT-IA now is expected to last for only 21 /2 years.

The fate of INSAT-II, due to be launched next July by the US space shuttle, should offer a second opportunity to work with such a complex satellite. Also, with the expected life-span of INSAT-IA shortened, there is talk of a third satellite in the series.

This growing space capacity raises questions of military, as well as civilian , applications. India, at present, has the technology for medium-range ballistic missiles. The SLV series might give it the capacity to launch long-range ballistic missiles as well. But there is no obvious link between India's space program, atomic-energy establishments, and the defense setup.

Certainly, the half-hourly photographs available through INSAT-I could be used for military intelligence, since they cover India's borders with Tibet, Pakistan, and Bangladesh, as well as the vast coastline. However, the Indian government has said repeatedly that its space and atomic-energy programs are meant for peaceful use and are to be bent to serve the purposes of development of the country alone.