Science & Technology

Space Race 2.0: Orbits of debris

Space waste threatens the existence of all satellites

 
By S S Jeevan
Last Updated: Sunday 12 May 2019
Space Race 2.0: Orbit of debris
Image: Getty Images Image: Getty Images

An unanticipated reaction to India’s first anti-satellite missile experiment on March 27—when the country successfully targeted its own decommissioned satellite—came from the National Aeronautics and Space Administration (NASA). Operation Shakti had created thousands of pieces of space debris, said Jim Bridenstine, an administrator with NASA.

About 95 per cent of all objects in orbit are either dead satellites or pieces of inactive ones. Space debris has been accumulating ever since humans began exploring the universe. The oldest known piece of orbital debris is the 1958 Vanguard 1 research satellite, which ceased all functions in 1964. Apart from abandoned satellites, there are more than 130 million objects with sizes ranging between 1 mm and 10 cm in orbit, according to the European Space Agency. These materials—pieces of broken satellites, deployed rocket bodies, human waste and other random objects—can be found in the Earth’s lower orbit within 2,000 km, or in geostationary orbit within 35,786 km above the Equator.

Historically, two incidents generated the maximum amounts of orbital debris. The first was when the Chinese government blew up one of its satellites in a missile test in 2007, and the second was in 2009, when a US commercial Iridium satellite smashed into an inactive Russian communications satellite called Cosmos-2251, creating thousands of new pieces of space shrapnel that now threaten other satellites in Earth's lower orbit.

“On average, a total of between 200 to 400 tracked objects enter the Earth's atmosphere every year,” according to the National Oceanic and Atmospheric Administration. Many of them don't survive, and instead burn up long before they hit the ground. But collisions of satellites with space debris are regularly taking place. In 2013, a Russian satellite collided with debris from Fengyun FY-1C, a Chinese weather satellite. A French military satellite crashed after it hit debris from a rocket in 1996. It is an endless list. As countries compete to deploy more satellites in the future, the dangers of space collisions have only increased. Of course, space agencies track these debris. NASA, for instance, tracks half a million pieces of space junk, but there are millions more that cannot be tracked as they are tiny. Even so, the US military issues 21 warnings of potential collisions each day.

Countries and space agencies are trying various methods to address the problem. Some are experimenting with various tracking technologies to avoid collisions. But it has its limitations. “For every tracked object, there are 20-30 untracked pieces of debris. Most are too small to be followed, but many could end a mission if they were to hit a satellite,” says Jamie Morin, executive director of the Center for Space Policy and Strategy at The Aerospace Corporation in Arlington, Virginia, USA. The British satellite, RemoveDEBRIS, which was launched in 2018, will use different methods to capture debris. Clearly, the world needs a global framework to coordinate spacecraft movements. Space agencies need to not only improve standards in precision tracking to predict collisions, but evolve ways to reduce space debris.

(This article was first published in Down To Earth's print edition dated May 1-15, 2019)

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