Friday, 27 March 2020

One year after India's ASAT test

click diagram to enlarge

Today it is one year ago that India performed an ASAT test codenamed 'Mission Shakti'. The test consisted of the on-orbit destruction of the Microsat-R satellite (2019-006A), launched specifically to function as target for this test. The intercept occurred at 285 km altitude, but created debris pieces with apogee altitudes much higher than that. I have earlier published an extensive OSINT analysis of the test in The Diplomat of 30 April 2019.

The test generated large amounts of debris. A total of 125 larger debris pieces have been tracked and catalogued by the US tracking network. Note that these only concern larger pieces: most of the generated debris probably was too small to be tracked.

Over the past year I have periodically posted an update on the status of these larger debris pieces on this blog. Whereas the Indian DRDO claimed at the time that all debris would have been gone 45 days after the test, the reality has been quite different: 45 days after the test, 29% (less than a third) of the larger debris pieces had reentered. It took 121 days for half of the pieces to reenter, and some 200 days before 75% of the tracked debris pieces had reentered.

One year after the test, some 114 of the tracked debris pieces have reentered according to CSpOC tracking data. And two more objects for which no decay message was published by CSpOC, 2019-006AR and EA, have reentered according to my own analysis with SatEvo, bringing the total tally of reentered larger tracked pieces to 116.

Nine, or some 7%, of the original 125 larger tracked debris pieces are still on orbit.

It concerns objects 2019-006V, AJ, AX, BD, DC, DD, DE, DM and DU (red orbits in the image below: the white orbit is that of the ISS, as a comparison).  They have apogee altitudes varying from 600 to 1500 km, and perigees generally near 260 to 280 km. Six of these are expected to reenter over the next half year 9 months. And the last debris pieces may not reenter before 2022-2023.

click image to enlarge

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