New Delhi: India on Saturday said its anti satellite (ASAT) missile test was done in a low orbit of less than 300 kilometres and at a particular angle to ensure that minimal debris were disbursed above into space to avoid damage to other satellites or the International Space Station (ISS).
India’s interceptor missile used in the ASAT test on 27 March has the capability to neutralise satellites up to 1,000 km in space, Defence Research and Development Organisation chief G. Satheesh Reddy said. But the ASAT test was “intentionally done at a lower orbit of 280 km to ensure that the debris decay very fast," Reddy said.
With the test done last month, India has mastered the capability to kill satellites at 300 km above the earth, Reddy said. "We don’t need any more tests at this orbit now," though he did not rule out the option of conducting more tests in the future.
Decisions on the weaponisation of space would be taken by the government, Reddy said.
He also clarified that a test done on 12 February was not an ASAT test, but a ballistic missile that was used to take out an electronic target — in response to media reports that the 12 February test was also an ASAT test that failed.
Reddy’s comments come against the backdrop of criticism from the US space agency — the National Aeronautics and Space Administration (NASA) — whose administrator Jim Bridenstine said that India’s ASAT test had created about 400 pieces of debris of which 24 were in an orbit near the International Space Station.
"That is a terrible, terrible thing to create an event that sends debris and an apogee that goes above the International Space Station. That kind of activity is not compatible with the future of human spaceflight," Bridenstine said at a NASA townhall with employees on Monday.
According to Reddy, before the physical ASAT test on 27 March, scientists had simulated the test to gauge the trajectory of debris and it was concluded that a direct head-on collision between the interceptor missile and the satellite would result in the least amount of debris going into space above — endangering the International Space Station which was in an orbit 120 km above the collision spot. Moreover, the International Space Station was not directly above the collision spot but in an orbit above the North Atlantic Ocean, over French Guyana, when India’s ASAT test took place over the Bay of Bengal, Reddy said.
“There is a risk (of debris from the Indian ASAT test) but the risk is for about 10 days which has been crossed," Reddy said. All the debris created by India’s test would take about 45 days to decompose, he added.
Reddy also responded to criticism by former home minister P Chidambaram, who had faulted the government for making India’s ASAT capability public. The DRDO chief said that a “mission of such nature" could not have been kept a secret technically, given the numerous satellites launched by different countries orbiting in space.
Explaining the strategic importance of the test, Reddy said India had demonstrated that it possessed the capability to intercept and kill a satellite — which acted as a deterrent vis a vis other countries. “This is a ground-based direct hit capability ... it works for defence also."
Almost all the technologies used for the ASAT test were indigenously developed with some 50 industries contributing components for the 13 metre missiles weighing 19 tonnes. Clearance to conduct the test was received in 2016 when the programme to develop the interceptor missile began in earnest, Reddy said. Of a team of 150 scientists involved in the project, 30-40 were women who were involved in radar software development, telemetry and ground computer systems, he added.
India’s ASAT test catapulted the country into an exclusive club of nations to acquire such a capability — the other countries being the US, Russia and China. New Delhi had successfully tested ballistic missile defence systems and it was one of these missiles that was upgraded for the ASAT test.
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