R-39UTTX / 3M-91 "Bark-Ost" - intercontinental SLBM with MIRV. The development of the SLBM version is reflected in the Program for the Development of the Armed Forces of the USSR for 1991-2000. The development of high-speed small-size combat units of the MIRVIS was conducted by SKB-385 in cooperation with the Research Institute of Instrument Engineering and the Zlatoust Machine-Building Plant from 1976 to 1985. The combat units are made with reduced visibility in the radar and infrared ranges. The draft version of the SLBM is reflected in the Program for the Development of the Armed Forces of the USSR for 1991-2000. Under the international agreement of 15.11.1990 (Geneva), the missiles of the D-19UTTX complex could be equipped with 8 MIRVS, which would ensure the non-violation of international agreements between the USSR and the United States to reduce strategic nuclear forces. The missile was equipped with a complex of anti-missile defense (CRMD). Combat units of SLBMs were tested in 19 launches of carrier K65MPfrom the Kapustin Yar test site (held until 1993). In June 1992, an addition was made to the draft project on replacing fuel at the 2 nd and 3 rd stages with less energy, which led to a reduction in the number of combat blocks from 10 to 8 pcs.
R-39UTTKh / 3M-91 "Bark-West" is an intercontinental SLBM with a monoblock warhead. The development of the SLBM version is reflected in the Program for the Development of the Armed Forces of the USSR for 1991-2000.