Of the many ideas put forward thus far regarding cleaning up all the ‘space trash’ this one sounds more promising and more realistic as it captures many as opposed to the one by one method. With 17,000 pieces of space debris and counting, a one-by-one method is probably best left to when the multitude has been removed.
The so-called space trash is not only satellites by launcher upper stages and even items smaller than a coffee cup.
The method they seem to be suggesting makes rendezvous with a drifting object and then through sophisticated sensors and autonomous robotic control decides the best approach. The difficulty lies in securing it and then getting it to its ultimate demise in a controlled burn up in the atmosphere. Apparently they are studying several capture mechanisms in parallel which makes sense, each utilizing a different style of capture.
While it may very well be one of the manners of capture the ESA is looking at, the one that comes to mind as having greater viability and perhaps would be able to take the most down at a time is one where once achieving space it breaks off into several separate satellites. Each holding a different corner of the ‘net’ so it could scoop them up running at them from behind or hold steady ahead of them and let them run capture themselves; a myriad of possibilities. Actually, the best place to deploy one might be above the geosynchronous orbit known as the Graveyard orbit (or junk orbit or disposal orbit.)
The ESA is designing this however for a much lower polar orbit (around 800km to 1000km) in which there is no shortage of traffic. None-the-less they are considering the deorbit options as well as higher orbits.
Either way, I think we’re in good hands as every space faring nation seems to be offering up something. Perhaps we can all get it done together!
There is yet another option as soon as the technology is complete- the Vasimir Space Tug. Ad Astra Rocket promised a space tug when the Vasimir engines have been completed as once this technology is there to power a spacecraft, it is there to power any sort of spacecraft.