Airbus is testing a big harpoon to snare rogue or redundant satellites and pull them out of the sky. The 1m-long projectile would be attached, through a strong tether, to a chase spacecraft. Once the target was captured and under control, the chase vehicle would then drag its prey down into the atmosphere to burn to destruction.
Airbus has been working on the concept for a number of years now, developing ever bigger systems. It is a response to the growing problem of orbital junk – old pieces of hardware that continue to circle the globe and which now pose a collision threat to operational satellites. Something in the region of 20,000 items of 10cm or larger are currently being tracked.
The latest Airbus harpoon is being designed with the capability to capture one of the biggest rogue items of the lot – Europe’s defunct Envisat Earth observation platform. This 8-tonne behemoth died suddenly in orbit in 2012. “Envisat is the outlier,” explained advanced project engineer Alastair Wayman.
“If we can design a harpoon that can cope with Envisat, then it should be able to cope with all other types of spacecraft including the many rocket upper-stages that remain in orbit.”