India’s first successful test of an anti-satellite weapon has produced an orbiting debris field consisting of at least 400 pieces, according to NASA administrator Jim Bridenstine. This debris now threatens the ISS, he said, calling India’s actions “not compatible with the future of human spaceflight.”
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Bridenstine made the comments yesterday while speaking to NASA employees at a town hall meeting, reports Space. NASA has identified approximately 400 pieces from the destroyed satellite, of which 60 are larger than 10 centimeters (4 inches) wide — large enough to be tracked by the U.S. military’s ground radars, SpaceNews reports.
Troublingly, some of these pieces have reportedly entered into orbits equal to or higher than the International Space Station, potentially putting the base at risk.
The debris field was created on March 27 when India destroyed its own Microsat-R with a ground-launched anti-satellite (ASAT) weapon. India is now the fourth country to have tested ASATs, the others being the U.S., the Soviet Union, and China. The conspicuous test, called Mission Shakti, was a demonstration of India’s newfound capacity in space, and a warning to rival nations to stay clear of India’s satellite fleet.
The doomed satellite was at an altitude of approximately 300 kilometers (185 miles) when it was destroyed, a height low enough such that the debris should “decay and fall back onto the Earth within weeks,” claimed India’s foreign ministry after the test. Precedent, however, suggests it could take much longer than that; in 2008, the U.S. destroyed a defunct satellite at an altitude of 250 kilometers, and it took about 18 months for all the material to fall back to Earth, according to SpaceflightNow.
Troublingly, NASA says around two dozen pieces of the destroyed Indian satellite were flung to orbits higher than the ISS, which currently orbits the Earth at an altitude of 410 kilometers.
“That is a terrible, terrible thing, to create an event that sends debris into an apogee that goes above the International Space Station,” said Bridenstine at the town hall. “And that kind of activity is not compatible with the future of human spaceflight. It’s unacceptable, and NASA needs to be very clear about what its impact to us is.”
The fear is that a shard of the shattered satellite could strike and damage the ISS. Even the slowest object in Low Earth Orbit moves at speeds approaching 7.8 kilometers per second, or 28,164km per hour, so an impact with the space station could be catastrophic.
Bridenstine continued: “We are charged with commercialising low Earth orbit; we are charged with enabling more activities in space than we’ve ever seen before for the purpose of benefiting the human condition, whether it’s pharmaceuticals or printing human organs in 3D to save lives here on Earth, or manufacturing capabilities in space that you’re not able to do in a gravity well.”
Such activities are placed at risk by these kinds of events, he said, and “when one country does it, then other countries feel like they have to do it as well,” he said. The NASA chief is worried about a copycat effect, in which other countries will now feel compelled to demonstrate their own anti-satellite capacity.
(Of course, NASA tested its own anti-satellite weapon in 2008.)
NASA, along with the military’s Combined Space Operations Center, estimated that the risk to the ISS increased by 44 per cent over a 10-day period. That said, Bridenstine assured the town hall audience that the six people currently on board the ISS aren’t in any immediate danger. The ISS is “still safe,” he said, adding the ISS could be manoeuvred if necessary, a contingency he described as having “low” probability.
Laura Grego from the Union of Concerned Scientists said the nearly 2,000 satellites currently in orbit are put at risk by such tests.
“Destroying satellites orbiting in altitude bands that are heavily used for both military and civil satellites also can have ripple effects, producing dangerous clouds of debris that could stay in orbit for decades or centuries, disabling or destroying any satellites they collide with,” said Grego in a statement. “The United States and other countries need to find a way forward that keeps space safe for everyone to use and doesn’t create new risks of conflicts on Earth.”