The S400 is a family of pressure fed liquid propelled rocket engines manufactured by Airbus. They burn MMH and MON as propellant, have a thrust range between 340420 newtons (94 lbf) and 450420 newtons (94 lbf) and can vary the O/F ratio between 1.50 and 1.80. The chamber and throat are made of a platinum alloy, it uses double cone vortex injectors and uses both film and radiative cooling. The S400 engines have been used as primary apogee engines for telecommunications satellites such as the Thales Alenia Space Spacebus as well as deep space missions such as Venus Express.