ISS at Increased Risk of Impact After Indian Anti-Satellite Weapon Test
All technologically advanced nations have at least a few space-based assets. In modern military conflict, those objects could become targets. Several countries have conducted tests with satellite-killing weapons, most recently India. Prime Minister Narendra Modi announced last week that the Mission Shakti test had successfully destroyed a satellite in low-Earth orbit. Now, NASA is expressing concern that the test could have placed the International Space Station at risk.
Space is big, but the space around Earth is feeling much more cramped lately. As the cost of reaching orbit drops, more countries and companies have launched spacecraft that will never come down of their own accord. That problem is multiplied a thousand-fold if one of those objects breaks apart, say because a missile smacked into it.
China is famous for conducting the most egregious test of a satellite smasher in 2007. In that test, China destroyed a satellite at an altitude of 537 miles. The debris from that event is still orbiting Earth where it poses a danger to other objects. The Indian test was intended to limit the potential risk, but NASA administrator Jim Bridenstine calls it a “terrible, terrible thing.”
India’s target in the test was a satellite it launched in January called Microsat-R with a mass of 740 kilograms (1,631 pounds). That’s a fairly large satellite. On March 27, India smashed it to pieces with Mission Shakti. The satellite was orbiting at an altitude of 175 miles, and the impact occurred on a downward trajectory. The intention was to send most of the debris into the atmosphere where it would not pose a danger to the ISS and other objects. It may not have worked out that way, though.
There are now at least 400 pieces of orbital debris from the destruction of Microsat-R, 60 of which are larger than 6 inches in size. Even one of the small chunks could spell disaster if it collided with the station at a high relative velocity. NASA and the US Strategic Command’s Combined Space Operations Center estimates that the ISS is now at a 44 percent higher risk of an impact. The ISS can move if there is enough warning, but NASA would obviously prefer not to have the increased danger in the first place.
Several space agencies and private companies are working on ways to remove orbital debris with lasers or giant nets, but all these approaches are years away from reality.