The D-9RKU-01 complex R&D embodied basic requirements of the Government Decrees adopted in February 1985 (a possibility to fire missiles from high latitudes) and in October 1986 (use of a new warhead of the middle power class instead of a standard warhead of the R-29R, R-29RL, R-29RK missiles). A new warhead was developed for the R-29RM missile and underwent flight development tests under different entry conditions. An advanced C-C composite material was first used for the warhead. The improvements of the missile systems expanded a list of missiles placed aboard the 667BDR submarine in any combinations. Flight tests during confidence and simulated firings of all modifications of the R-29R missiles confirmed the preset reliability indexes.