sentences:  On March 24, 2009, the Nigerian Federal Ministry of Science and Technology, NigComSat Ltd. and CGWIC signed a further contract for the in-orbit delivery of the NigComSat-1R satellite.NigComSat-1R also uses the DFH-4 satellite platform with improvements over the previous satellite, and was delivered in the fourth quarter of 2011 as a replacement for the failed NigComSat-1.It was successfully launched on December 19, 2011.