> No, it takes a lot of energy to get out of orbit
Does it? It takes ~10000 m/s of delta-v to reach low Earth orbit, but afaik only about extra ~30 m/s to deorbit, with aerobraking taking care of the rest of the velocity. Or is there any extra intricacy in the details?
They were talking about escaping orbit (reaching escape velocity which is ~41% higher than the orbital velocity and requires getting more fuel into orbit), not degrading the orbit so that the satellite burns up in the atmosphere. As the article discusses, the latter has the flaw of putting alumina particles in the upper atmosphere which remain there for many years.
Does it? It takes ~10000 m/s of delta-v to reach low Earth orbit, but afaik only about extra ~30 m/s to deorbit, with aerobraking taking care of the rest of the velocity. Or is there any extra intricacy in the details?