text: Q:
  
  Could a skyhook be used to remove space junk?
  
  Is it possible to remove the space junk having orbital velocity with the help of a skyhook? 
  Has any country in the world planned to place a skyhook in orbit?
  
  A:
  
  There is the ElectroDynamic Debris Eliminator (EDDE) notion that seems to be pretty serious.  Not clear if they have realistic funding or not.
  This is basically a multisegmented tether that using solar panels along its length for energy generation, rotates and grabs debris in a net at the end to then deorbit.
  A key design feature is that if it gets severed the remaining elements can continue to operate as two smaller EDDE vehicles.
  
  A:
  
  Astrium is working on a space harpoon capture system. They have been awarded a study contract by the French space agency CNES to develop space vehicles that can remove large items of debris from Earth's orbit. Their idea is to develop a pneumatic space harpoon that a spacecraft would fire into larger space debris targets and use tether to drag them out of orbit and into the atmosphere:
     
  The harpoon design is trying to minimize secondary debris from puncturing the target's body. It has a set of barbs, a shock absorber section that is the wide part in the photograph above and releases the barbs into open, hook-like position after impact, and a shaft that is inserted into the pneumatic gun that holds the tether with which the target is later towed by into the atmosphere.
  More information and references:
  
  Astrium press release: Astrium to study removal of large space debris, April 17, 2013
  The Engineer: Space harpoon could tackle satellite debris problem, April 18, 2013
  CNN: Space harpoon plan to nail orbital garbage, April 21, 2013
  CNN Video: Astrium Space Hook - How to capture space debris, April 18, 2013
  YouTube: The Engineer report on Astrium Space Hook (with demonstration), April 18, 2013
  Al Jazeera Video Report: UK floats harpoon solution to 'space junk', April 22, 2013
  
  