Alone among the Western nations, France has continued to pursue the operational deployment of ramjet-powered air-launched stand-off missiles since the late 1940s. While the USA experimented with ramjet propulsion during the late 1940s and 1950s, with test vehicles such as Glenn Martin PTV-N-2 Gorgon, the preference was for turbojet, and latterly turbofan propulsion for air-launched stand-off weapons.
France deployed the Aerospatiale ASMP medium-range nuclear missile in 1986, which entered service with both the air force and navy. In pursuing a ramjet-powered Mach 2-3 solution for its "sub-strategic" nuclear requirement, rather than a subsonic US cruise-missile approach, France acquired a much more expensive weapon. It justified the expense by arguing that a high-Mach/high-altitude weapon provided the best means of penetrating air defences, particularly with a limited number of platforms and missiles.
France continues to study the technologies for both ramjet- and supersonic-combustion ramjet (scramjet)-powered stand- off weapons. Aerospatiale, with research agency Onera, has carried out several studies into future systems.
The French air force's intention to replace the ASMP with the ASLP, an increased-range, liquid-fuelled ramjet design, led to Aerospatiale and Onera beginning the Chefren technology-demonstrator programme. The programme aimed, among other things, to produce a considerably more "furtive" or stealthy weapon.
France's time scales for a successor to the ASMP have been considerably stretched, and Aerospatiale is now working on the ASMP Plus, rather than the ASLP. At a research level, even more advanced configurations have been examined, including the MARS scramjet-powered missile design for a Mach 5-plus air-launched strategic missile.
Ramjet/Scramjet missile propulsion for stand-off weaponry appears to be once more finding favour in US circles, and several studies are being carried out. It remains to be seen what projects could emerge from the US Department of Defense's classified budget.
Russia has continued its traditional interest in ramjet propulsion, and is looking to include the technology in air-launched strategic weapons. Cruise-missile house Raduga showed its GELA test vehicle at the Moscow air show in 1995, but beyond saying that the GELA programme was exploring high Mach number ramjet propulsion, the bureau would not discuss the programme. Given its design, however, it seems reasonable to assume that the GELA programme is intended to develop an air-launched strategic cruise missile, perhaps to supersede the abortive NPOMashinostroenia AS-X-19 Koala programme. The GELA appears, however, to have suffered the same fate as the AS-X-19.
Source: Flight International