Aerospace News, Early May 2019



The world’s largest aircraft has taken to the sky for its initial test flight over the Mojave Desert. The first flight of the largest all-composite aircraft ever, the Stratolaunch, was completed earlier this month.


With a wingspan greater than the length of an American football pitch, the Stratolaunch aircraft took to the sky from the Mojave Air and Space Port in North America. Designed to launch rockets into low Earth orbit, it achieved a maximum speed of 189 miles per hour. The lasted for 2.5 hours at altitudes up to 17,000 feet, and its reinforced centre wing can support multiple launch vehicles, weighing up to a total of 227,275Kg.


The company behind the plane, Stratolaunch, was established in 2011 with its chief mission to get innovative ideas off the ground by making space launch more reliable, affordable and accessible. As part of the initial flight, the pilots evaluated the aircraft’s performance and handling capabilities before landing successfully back at the spaceport.



Designed to drive space planes to orbit at Mach 5, and take airliners around the world in just a few hours, the Sabre air-breathing rocket engine has just passed a crucial testing phase. Synergetic Air Breathing Rocket Engine, or Sabre, is a new type of flexible engine for propelling both high-speed aircraft and spacecraft. Reaction Engines devised the unique rocket engine to allow aircraft to fly much faster than traditional jets.


However, unlike jet engines, Sabre can also operate in a rocket mode outside of the atmosphere, and this could potentially offer the next generation of reusable space launch vehicles. There are three core elements to the Sabre engine; the pre-cooler, the engine core that has a smart thermodynamic cycle to manage heat and fluid flow, and the thrust chamber situated at the rear.


The pre-cooler element of the air-breathing rocket engine successfully passed its first phase of high-temperature testing. The testing was designed to directly replicate supersonic flight conditions.


It showed the ability to handle the simulated conditions of flying at more than three times the speed of sound. It did this by successfully quenching a 420°C stream of gases in less than 1/20th of a second. Future tests are planned at temperatures in excess of the 1,000°C expected during Mach 5 hypersonic flight. Sabre can be considered a hybrid of a jet engine and a rocket engine.



At slow speeds and at low altitude, it would act like a jet, burning its fuel in a stream of air from the atmosphere. At higher speeds and altitude, it would then transition to its rocket mode, combining the fuel with a small supply of oxygen the vehicle had carried in flight.