A-Sat test poses risk to ISS, its astronauts, says NASA chief
NEW DELHI: Indian space and missile experts have rubbished National Aeronautics and Space Administration's claim that 400 pieces of orbital debris created due to recent India's anti-satellite missile (A-Sat) test are posing dangers to astronauts aboard the International Space Station (ISS).
Nasa head Jim Bridenstine, while addressing his employees in the US after India's A-Sat missile test, said, "India destroyed a satellite at a relatively low altitude of 300 km, well below the ISS and most satellites in orbit. But 24 of the pieces "are going above the apogee of the ISS."
"That is a terrible, terrible thing to create an event that sends debris at an apogee that goes above the ISS. It's unacceptable and Nasa needs to be very clear about what its impact to us is," he said.
Bridenstine said, "What we are tracking right now, objects big enough to track. We're talking about 10 cm or bigger - about 60 pieces have been tracked."
He said, "The ISS is still safe. If we need to manoeuvre it, we will. The probability of that I think is low. But at the end of the day we have to be clear also that these activities are not sustainable or compatible with human spaceflight."
Bridenstine is the first top official from the Trump administration to come out in public against India's ASAT test.
Rubbishing such charge against India, former DRDO chief V K Saraswat said, "It is a mere speculative statement. This is a typical American way of dealing with the progress India made. As far as our A-Sat missile test is concerned, all these objects do not have enough velocity to survive in space for too long. With no energy or momentum, these debris generated at the 300 km altitude after the A-Sat test will ultimately fall and burn out in the earth's atmosphere."
On existing space debris, Saraswat reportedly told Times of India, "Lakhs and lakhs of space debris are already roaming in space, what about the danger from them to ISS. Every year, 190 satellites of varying sizes are launched in the low-earth orbit and this number is going to grow. Each satellite launch creates a lot of debris. So talking about some space debris from India's A-Sat test is meaningless."
The ISS is orbiting the Earth at an altitude between 330 and 435 km, well above the 300km altitude where India destroyed a DRDO payload Microsat-R weighing 740 kg with an interceptor missile under Mission Shakti project in order to gain the A-Sat missile technology.
Former DRDO scientist Ravi Gupta said, "Such comments by the Nasa head are discriminatory and irresponsible. It's more of a propaganda. India's test was conducted at 300km altitude and the ISS is at much higher altitude. There is a remote possibility of debris moving upwards and even if some pieces are moving upwards, they will ultimately fall down as they will lose energy or momentum they gained during the missile-satellite collision. Second, the US is blaming us but it itself had conducted a lot of A-Sat tests in the past which generated thousands and thousands of big size space debris, which already pose danger to all space assets of every country, including ours. Likewise, a lot of space debris was created during the similar tests conducted by Russia and China. "
According to United Nations Office for Outer Space Affairs (UNOOSA), only 1,400 of the 19,000 artificial objects currently being tracked in the earth's orbit are functional satellites. The remaining objects are collectively known as "space debris".
According to an estimate by the European Space Agency, there are over 34,000 pieces of debris in orbit that are larger than 10cm in size, close to a million pieces between 1cm and 10cm, and 128 million pieces of debris less than a centimetre in size.