First, this is extremely high for LEO, ~1200km. Drag is negligible, decay will take thousands of years. At around ~800km, solar sails start to become practica

First, this is extremely high for LEO, ~1200km. Drag is negligible, decay will take thousands of years. At around ~800km, solar sails start to become practical because aerodynamic drag drops below photon pressure. Ion thrusters and photovoltaics are COTS techs which are vastly more powerful than solar sails, which exist only at the prototype/demo stage. Ion thrusters are practical to fight drag down to around ~200km given the right design, or are perfectly happy at 300-350 given a typical suboptimal design. GOCE managed it down to ~230km, after performing a multiyear mission at ~260km: http://www.spaceflight101.com/goce-re-entry.html http://www.spaceflight101.com/goce-re-entry.html