The missile's body is an
all-welded construction made of
hard-worked AMg6 (АМг6)
aluminium-magnesium-alloy panels, which underwent a two-step process of
deep industrial etching and
mechanical milling, reducing the plate thickness to one-fifth and one-ninth of the thickness of the original plate. Directly beneath the warhead, the
instrumentation necessary for
guidance of the
missile was housed inside of a hemispherical compartment formed by the upper
bulkhead of the oxidiser tank. This design decision allowed the easy removal of the guidance system from the missile for maintenance and removed the need for a service hatch. To maximize the volume of propellant available inside the missile, the upper oxidiser tank and the lower fuel tank shared one
common bulkhead instead of one bulkhead each as it was absolutely necessary to use every bit of
volume available to be able to fit the
missile into a
submarine. Another novelty was factory fueling with the subsequent "ampulization" of the tanks by
welding filling and drain valves. Initial submarine testing began on 9 December 1972 on board the K-102, a project 605 class submarine, a modified
Project 629/ NATO Golf class lengthened 17.1m (formerly B-121), to accommodate four launch tubes as well as the Rekord-2 fire control system, the Kasatka B-605 Target acquisition system and various improvements to the navigation and communications systems. Initial trials ended on 18 December 1972 because the Rekord-2 fire control system hadn't been delivered yet. After a number of delays caused by several malfunctions, test firings were finally carried out between 11 September and 4 December 1973. Following the initial trials, the K-102 continued making trial launches with both the R-27 and the R-27K, until it was accepted for service on 15 August 1975. Using external targeting data, the R-27K/SS-NX-13 would have been launched underwater to a range of between , covering a "footprint" of . The
Maneuvering Re-Entry vehicle (MaRV) would then home in on the target with a CEP of . Warhead yield was between 0.5-1 Mt. The missile system never became operational, since every launch tube used for the R-27K counted as a strategic missile in the
SALT agreement, and they were considered more important. Although the R-27K could fit in the launch tubes of the Project 667A (NATO
Yankee class), the subs lacked the necessary equipment to target and fire the missile.
Zyb (Suborbital Launch Vehicle) In 1992, there was an ongoing effort to convert surplus
Soviet Navy SLBMs which were taken out of service into
launch vehicles. The Zyb
sounding rocket was created on the basis of the R-27 specifically for performing experiments in a
Microgravity environment. The rocket would be launched in a ballistic arc, exposing the payload to
weightlessness for 17 to 24 minutes, depending on payload mass. The trajectory would reach its
apogee at 1800 km or 1000 km for 650 kg and 1000 kg payload mass respectively. The rocket provided 1.5m3 of payload volume. The Zyb sounding rocket was launched a total of three times.{{cite web
Derived missiles In 1992, the
Makeyev Rocket Design Bureau signed a contract with
North Korea regarding the creation of a R-27 derived launch vehicle. As a result of this, the very similar
North Korean
Hwasong-10 "Musudan"
IRBM was derived from the R-27,{{cite web It is suspected that a modified subvariant of this missile was then sold to the
Iranian Military in 2005 under the designation
BM-25 "Khorramshahr".{{cite web == Operators ==