Although Russia is in the midst of replacing Cold War era RS-18 (SS-19) ICBMs with the new solid fuel RS-24 it test fired what was thought to be one of the remaining RS-18s in late October. Later it turned out that this successful test was not of the RS-18 but its successor, the RS-28. One thing the RS-28 is meant for is the new hypersonic glide vehicle project Russia announced in 2013 but was believed to have suspended because of budget cuts brought on by low oil prices and sanctions.
It was believed that the new heavy ICBM, the RS-28, would be ready for testing before the end of 2016. RS-28 has been in development since 2009 and was originally scheduled to enter service in 2018. That has now been delayed until 2020, or even later if the 2016 tests do not go as expected. So far the RS-28 appears to have worked. Russia has had a growing number of quality control problems throughout the Russian space problem and military tech development in general. The cause was the return of a market economy to Russia in the 1990s. At that point most of the more talented people in defense industries found better paying jobs in the commercial sector or overseas. No solution to this has been found, especially not with Russia suffering from an economic recession and pervasive corruption. Despite the fact that the government has devoted a lot more money and management talent (also in short supply) to nukes, ballistic missiles and nuclear subs, the problems and delays persist.
The government believes the RS-28 is essential for state security because it can carry nine or more independently targeted warheads and will be the most important weapon in its ICBM arsenal. Moreover the missile RS-28 is replacing (R-36M) is aging to the point where refurbishment is no long able to keep these four decade old missiles operational. The Russians saw this problem coming and in 2003 decided to refurbish its force of 1970s era R-36M (SS-18 or "Satan" in the West) ICBMs so they could remain in service another 10-15 years (2013-18).
The RS-18 was developed as a "light" ICBM, in effect, a competitor for the U.S. Minuteman series. The RS-18 was the first Russian ICBM to carry MIRV. The RS-18 carries six warheads and has a range of 10,000 kilometers. Russia is also extending the life of its heavier (217 ton) RS-20 ICBMs to 30 years. This missile carries ten warheads and is also being converted to launch satellites or hypersonic glide vehicles
The R-36M was designed in 1969, first tested in 1972 and entered service in 1975. It's the largest ICBM the Russians ever built, with a liftoff weight of 210 tons and a warhead weighing eight tons. While it's a liquid fuel rocket, storable liquid fuel is used. This avoids lengthily fueling procedures common with earlier Russian ICBMs. Modifications and upgrades for the missile produced six separate models, the last one entering service in 1990. Russia wanted to refurbished a hundred of the most recently built (in the 1980s, for the most part) R-36Ms. Shortages of cash and resources reduced the number refurbished and as of 2016 only about fifty are operational. By 2018 only about 30 will be working and by 2020 none will.
The secretive hypersonic glide vehicle project was something that began during the Cold War but never got into service. Suspicions that Russia had changed its mind may have been a side-effect of China revealing in early 2016 that they had perfected the technology for a maneuverable ballistic missile warhead. This came a little after it was revealed that since 2014 China had conducted six tests of a maneuverable gliding warhead for ballistic missiles. Five of the six tests were successful and this hypersonic glide vehicle was officially known as the DF-ZF.
In effect this Chinese hypersonic glide vehicle is a warhead that can glide rather than simply plunging back to earth and is maneuverable enough to hit small moving targets in space or down on the surface. The DF-ZF was initially developed as China sought to perfect a version of the DF-21 ballistic missile that could hit moving warships at sea. DF-21 is a 15 ton, two stage, solid fuel missile. The DF-21D (the carrier killer version) missile using the DF-ZF warhead is also more difficult for anti-missile missiles to hit. This is what the Russian hypersonic glide vehicle is designed for.
Russia and the United States had developed this technology much earlier but neither has deployed it in the form the Chinese appear to favor. The original work in this area was by the Germans during World War II. The U.S. and Russia both investigated the concept more during the Cold War but never felt it worth building. In the 1990s the United States proposed reviving work on hypersonic glide vehicle for its Prompt Global Strike system. This would put hypersonic glide vehicle warheads, using high-explosive and not nuclear explosives, on ICBMs. This meant a very expensive weapon that could hit a target anywhere on earth in less than an hour of the order being given. In any event the United States successfully tested its version of the hypersonic glide vehicle in 2011 but with the defense budget shrinking the project was halted. This was encouraged when a 2014 hypersonic glide vehicle test failed.