A scramjet is reminiscent of a ramjet. Future hypersonic aircraft may use some type of ramjet or rocket propulsion. Navaho missile and the USSR's Burya, both intercontinental cruise missiles with ramjet propulsion. The use of a ramjet propulsion system enables sustained speeds without deceleration throughout its flight. It is propelled by an Integrated Ramjet Rocket Engine. It was replaced by a much shorter range ramjet missile system called the Bloodhound. Another high-speed powerplant is the ramjet. This allows ramjet combustors to burn at a higher temperature. In 1939, Merkulov did further ramjet tests using a two-stage rocket, the R-3. This solves the fusion reactor problem for the ramjet. It was fitted with Rochester Ramjet fuel injection. A ramjet is designed around its inlet. This acceleration gives the ramjet forward thrust. These toys were recolored and released as fellow Decepticons Ramjet, Skywarp and Thundercracker. The GIRD-08 phosphorus-fueled ramjet was tested by firing it from an artillery cannon.