400N Monopropellant Thruster
The 400N monopropellant thruster uses the storable propellant hydrazine N2H4 and is designed for both long term steady state and pulse mode operation.
This thruster is primarily used for the attitude and roll control of the Ariane 5 launch vehicle during its ascent. After Ariane 5 upper stage separation, the thruster is used for ACS manoeuvres preparatory to the separation of one, or more, spacecraft into their initial orbit.
The thruster is also used for re-entry attitude control applications as successfully demonstrated during the Atmospheric Re-entry Demonstrator (ARD) mission.
The thruster operates over a wide pressure range and is thus ideal for blow down propulsion systems.
The combustion chamber and nozzle are manufactured from Haynes 25 alloy. The structure is also designed to serve as a heat barrier for protecting both the propellant valve and spacecraft structure.
An optional internally redundant catalyst bed heater and thermal insulation guarantees optimum start up conditions. In addition, the thruster is qualified for multiple cold starts.
400N HydrazineThruster Heritage and Future Missions
Since 1996 the 400N Hydrazine thruster has been used on all Ariane 5 G, GS and ES versions for the roll and attitude control manoeuvres.
To March 2015, the thruster has flown on 30 Ariane 5 flights with more than 170 units.
As a further application of the technology gained with this thruster, a derivative has been developed, qualified and flown successfully on the ESA Atmospheric Re-Entry Demonstrator (ARD).
The application envelope of this thruster was further extended in 2005, when it was used within the roll controll systems of the IXV (re-entry technology) and EXM2016 Descent Module. The thruster is also being qualified for satellite de-orbiting manoeuvres where long steady state firings are demanded.