The ESA has been testing the possibility of using one of mankind’s earliest inventions to cope with one of its newest challenges, by testing a concept that would allow satellites to net and de-orbit space debris in a safe and controlled manner. Space debris is now an ever-increasing problem.
Currently, there are around 12,000 objects exceeding 10 cm in size, and millions smaller orbiting Earth at speeds up to 15 km per second (9.32 miles p/s). If any such object impacted with an operational satellite, or possibly even the International Space Station, the results could be catastrophic. In order to prevent such an occurrence, any satellite due to be placed into an orbit of less than 2,000 km (1,243 miles) above the Earth are now required to incorporate technologies that would either de-orbit the satellite automatically, or push it in to a safe graveyard orbit upon reaching the end of its lifespan.
However the question remains, what can you do with the numerous defunct satellites that are already cluttering up low-Earth orbit? Such objects represent a significant long term hazard, as a collision between a satellite and another object could produce a cloud of smaller debris. To tackle the challenge, ESA has proposed placing satellites in orbit designed to capture large inert objects and manipulate them back into Earth’s atmosphere.
However, there are inherent difficulties that make such an operation a daunting prospect. For example, one could not simply dock with the object as you would with another spacecraft, as the debris would most likely be tumbling in an unpredictable manner. Instead, ESA proposes to snag the harmful objects with a simple, low-tech net.