 The demonstration of electric propulsion was an ion engine carried on board the SERT-1 (Space Electric Rocket Test) spacecraft, launched on 20 July 1964 and it operated for 31 minutes.A follow-up mission launched on 3 February 1970, SERT-2, carried two ion thrusters, one operated for more than five months and the other for almost three months.By the early 2010s, many satellite manufacturers were offering electric propulsion options on their satellites—mostly for on-orbit attitude control—while some commercial communication satellite operators were beginning to use them for geosynchronous orbit insertion in place of traditional chemical rocket engines.