India today became the sixth country in the world to launch its own satellite into space.

The 77-pound satellite was blasted into an orbit just outside the earth's atmosphere by a seven-story-high, four-stage, solid-fuel rocket early this morning.

It is circling the earth once every 90 minutes.

The space launch was seen as a remarkable achievement for a country that still uses bullock carts as a prime mode of transportation. Despite its poverty, however, India has the third largest pool of technically trained manpower in the world.

The $25.25 million satellite launch vehicle was an all-India effort. The 17-ton rocket was built by Indian scientists, as was the tiny payload, which was designed mainly to monitor the launch vehicle's performance.

"This is a great day for India and for Indian science," said Prime Minister Indira Gandhi as she announced the successful launch to a cheering Indian Parliament.

India's 17-year-old fledging space program has suffered a series of setbacks before this launch. An attempt last August to orbit a satellite failed when the launch vehicle dropped into the Bay of Bengal about five minutes after liftoff as the second stage failed to ignite.

While today's launch was billed as a peaceful experiment, the head of the Indian space research organization, Satish Dhawan, said today it gives India the capability to develop intermediate-range ballistic missiles. "Any country which can place a satellite in orbit can develop an IRBM," he said.

But one close Western observer of India's space program said it is unlikely that the solid-fuel, four-stage rocket will be used for military purposes because there are too many chances of failure in that type of system.

"You can give India high marks for peaceful applications on this one," he said. "No one would ever build a four-stage solid-propellant rocket for military purposes."

He explained that India picked the least expensive, easiest route to put a satellite into orbit, but in doing that skipped important rocket technology that would be needed if it was to be used for military purposes. Four stages, which have to ignite one after another at the proper time, leave too many chances for problems to develop, the source said.

Dhawan said today's successful launch will pave the way for liquid fuel rockets that can carry larger payloads of up to 1,300 pounds.

Nonetheless, the successful launch of the satellite has provided information that could be used for military purposes and has underscored India's place as the most powerful nation on the South Asian subcontinent.

Indian analysts have noted, for example, that the guidance system used today could serve either an intermediate-range or intercontinental ballistic missile system.

Moreover, a space satellite designed for peaceful purposes such as seeking mineral resources can easily become a spy in the sky searching out troop movements in neighboring countries.

India, for instance, has been at war with Pakistan three times in the 33 years since they were carved from British India and given their independence. yIn 1962 it fought a border war with China, which put its first satellite into orbit in 1970 and now has ICBM capability.

While India is not believed to have moved ahead with a nuclear weapons program, it did explode an underground atomic device in 1974. In a parliamentary debate on its defense program yesterday, some members argued that it should move ahead to develop atomic weapons. Members of the ruling Congress-I Party argued that China already has atomic weapons and that Pakistan is trying to develop them.

The Soviet Union was the first to lift a satellite into space when it launched Sputnik in 1957, setting off a space race with the United States, which successfully launched its first satellite a year later. France followed in 1965, and both Japan and China launched satellites in 1970.