Orbital Propulsion Centre, Lampoldshausen, Germany ArianeGroup Home page of the ArianeGroup Orbital Propulsion Centre, Munich, Germany

400N Hydrazine

Close Overview 1 N Hydrazine Thruster 20 N Hydrazine Thruster 400 N Hydrazine Thruster


400N Monopropellant Hydrazine Thruster

For launch vehicle and upper stage RACS and the controlled re-entry of spacecraft.


400N Bipropellant Thruster
400N Monopropellant Thruster

General Description

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.




400N Monopropellant Thruster Characteristics
Thrust range vac
120 to 420N
Isp range vac
212 to 220 sec
Nominal mass flow range
58 to 190 g/s
Supply pressure range
5.5 to 26 bar
Minimum impulse bit range
< 9 Ns
Shortest 'on' time
16 ms
Nozzle area ratio
Overall length
325 mm
Nozzle end diameter
67 mm
P1 - design 2.7 kg
P2 - design 3.8 kg
Environmental loads
16.2 grms
Monopropellant grade hydrazine (N2H4)


Total Impulse
< 188 kNs
Total number of pulses
> 3900 cycles
Total hydrazine throughput
~ 300 kg
Total operating time
> 850 s
Longest steady state burn
450 s
Number of cold starts < 25° C





400 N Hydrazine Thruster Cluster Integrated to the Ariane 5 
						Vehicle Equipment Bay
400N Hydrazine Thruster Cluster Integrated to the Ariane 5 Vehicle Equipment Bay


Hydrazine Thrusters
(PDF Brochure)

Hydrazine Thruster Brochure (pdf)

This brochure is available to view online from where it may be downloaded.


Get the latest version of the free Adobe Acrobat Reader  Adobe Reader

If you require the printed version of this brochure, or more detailed information about this product please contact us.


See the complete list of our space propulsion brochures available for download.