Every week, on average, a substantial, inert satellite drops into our atmosphere and burns up. Monitoring these reentries and warning European civil authorities has become routine work for ESA’s space debris experts.
Each year, about 100 tonnes of defunct satellites, uncontrolled spacecraft, spent upper stages and discarded items like instrument covers are dragged down by Earth’s upper atmosphere, ending their lives in flaming arcs across the sky.
Some of these objects are big and chunky, and pieces of them survive the fiery reentry to reach the surface. Our planet, however, is a big place, mostly covered by water, and much of what falls down is never seen by anyone, sinking to the bottom of some ocean, or landing far from human habitation.
While still in orbit, these and many other objects are tracked by a US military radar network, which shares the data with ESA, since Europe has no such capability of its own.
It’s the task of ESA’s Space Debris team to look at these data and issue updates to ESA Member States and partner civil authorities around the globe.