In March 2018 Russia announced the suspension of the RS-26, one of the two ICBM projects that are designed to use the Avangard, a revival of a Cold War era hypersonic glide vehicle system. RS-26 was a solid fuel missile based on the Topol M, which was the first successful solid fuel ICBM missile Russia was been able to deploy. It is comparable to the 1960s era U.S. Minuteman ICBMs. Solid fuel is tricky to manufacture, and after many abortive attempts, the Russians stuck with liquid fuel until the 1980s. They finally perfected their solid fuel technology in the 1980s, with the successful test launch of the 45 ton Topol in 1985. The 52 ton Topol-M followed ten years later. Both missiles have a range of 10,500 kilometers. This is the second time Russia ran into problems adapting the Topol M for other uses. The first effort was to turn Topol M into Bulava, a SLBM (Sea Launched Ballistic Missile) for the new Borei class SSBN ((ballistic missile nuclear subs). The Bulava problems were largely caused by a shortage of competent engineers and manufacturing specialists. Getting Bulava to work took a lot longer and cost a lot more than expected. Sensing the same pattern with the RS-26 Russia “suspended” work on this until 2027, or whatever future time when the personnel and manufacturing quality control problems can be solved.
Meanwhile, the other new missile designed to carry Avangard, the RS-28, is having fewer problems but is still behind schedule and officially not expected to be ready until 2021. Realistically the mid-2020s is more likely.
RS-28 development began as a replacement for Cold War era ICBMs that are rapidly becoming too old and unreliable to use. By 2016 the RS-28 had also evolved into the primary carrier for 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. The crises is still present and the defense budget has undergone cuts for several years in a row. Yet the Avangard project remained active.
The RS-28 was originally scheduled for testing before the end of 2016. That did not happen and there followed the usual succession of delays because of technical or manufacturing problems. RS-28 has been in development since 2009 and was originally scheduled to enter service in 2018. 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 longer able to keep these decades 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 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 refurbish 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 were operational. By 2018 only about 30 will be usable and by 2020 none will. The RS-28 is very similar to the R-36M, weighing 220 tons and a war head hauling up to ten tons of smaller warheads (up to 15) or 24 Avangard vehicles.
The secretive Avangard 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. Now, this effort has been revived, sort of.
The United States moved ahead with reviving its Cold War era hypersonic glide vehicle ballistic missile warheads. In late 2017 the U.S. revealed several active research projects like TBG (Tactical Boost Glide) and HAWC (Hypersonic Air-Breathing Weapon) which are similar in size and shape to the cruise missiles carried by bombers and launched from high altitudes into orbit or remain in the atmosphere but moving a hyper speeds (over 5,000 kilometers an hour). This is similar to the X-51A Waverider project that was halted in 2013 but not forgotten. The problem with X-51A was that it could not be made reliable enough. A 2010 flight test had the 8 meter (36 foot) long, cruise missile-like X-51 aircraft boosted to 3,300 kilometers an hour, using a solid fuel rocket, at which point the scramjet engine took over, and successfully operated for over two minutes, achieving speeds of nearly 6,000 kilometers an hour. This was the longest a scramjet had ever operated (the previous best was ten seconds). By 2013 the 4th test got the liquid fuel engine going for five minutes.
What makes scramjets work is the compression of incoming air, without the use of a fan system (as in conventional jet engines). But while scramjets have been in development for half a century, the lack of adequate materials (that can handle the high heat and pressure), and adequate design tools, frustrated attempts to build workable, and reliable, scramjets. Scramjets have few moving parts but must cope with very extreme conditions and the design challenges have proved very frustrating. The recent X-51 tests, like all previous ones, ended with the aircraft crashing. The next step was to get longer hypersonic engine use, de-acceleration, and landing via parachute (and eventually an auxiliary engine.) Going beyond the 2013 test proved too expensive and time consuming to continue when there were cheaper alternatives available and these depended more on getting into orbit and letting gravity provide and maintain the high speed. It was definitely easier to achieve those high speeds with orbital technologies like TBG and HAWC. Or the new Chinese systems like DF-ZF.
Russia stresses the need for Avangard to deal with American missile defense systems. This doesn’t make sense to Westerners because the American anti-ICBM systems are limited and meant to deal with small numbers of ICBMs from North Korea or Iran. Russia interprets it differently because since 2010 Russian leaders have been blaming internal problems on the growing NATO threat. The reality is that the NATO threat is a myth but the growing economic problems are not. This is made clear via opinion polls and international economic surveys. The corruption rankings put Russia among the most corrupt nations and those are the ones that have the worst economic and military performance. The most recent corruption surveys show Russia as more corrupt than China and getting worse. Avangard is an expensive defense against an imaginary threat. Meanwhile, the growing corruption and shortage of competent people (who are leaving Russia or avoiding defense industries) makes it more and more difficult to complete high-tech weapons projects of any kind.