MTSAT-1R (also known as Himawari 6) was successfully launched on a H-IIA on 26 February 2005 and became partially operational on 28 June 2005 - the aviation payload was not functional as two MTSATs are required for air traffic control. GOES-9 was decommissioned when MTSAT-1R came online in June 2005. Its solar sail counteracts the torque produced by sunlight pressure on the solar array. The trim tab on the solar array makes small adjustments to the torque balance.