1N Hydrazine Thruster

All the space you need

Reliable control of small and midsize spacecraft

1 N Mono-Propellant Thruster

1 N Thrusters in SpaceMore than 500 units of the thruster´s first and

second generation operate successfully in space

to date. Hundreds of units will follow.

Heritage

The 1 N thruster is a small rocket engine for attitude,

trajectory and orbit control of small satellites and

deep space probes.

The thruster was derived from a space proven 0,5 N

thruster, of which some 165 units were flown on

OTS-2, ECS, Marecs, Telecom-1, Skynet 4 and

NATO-IV.

The thruster has experienced multiple improve-

ments since the above mentioned applications,

especially in view of minimum possible production

cost. Today it may be called a low cost thruster.

The thrusters are equipped with propellant valves

from either MOOG, USA, or from A.E.R., France

depending on customer´s request. The thruster is an

All European Product when euipped with the

A.E.R.-valve.

EADS Space Transportation is engaged in the

monopro-pellant hydrazine propusion technology

since 1966. It can look back on longlasting

experience in development and production of

hydrazine thrusters and propulsion systems for

numerous commercial, scientific and military

spacecraft and for attitude control of Europes large

launcher Ariane 5.

The family of monopropellant hydrazine thrusters

ranges from 0,5 N to 400 N, most of them available

with either straight or canted expansion nozzle.

Globalstar 365 1997 - 2000

Jason 1 4 2001

Rocsat-2 / Formosat-2 4 2004

Cosmo-SkyMed 1 6 2005

TerraSAR-X 8 2005


Radarsat-2 6 2006

Galileo GSTB-V2 8 2006



Herschel Planck 4 2007

Theos 4 2007

Pleiades H1 8 2008

Pleiades H2 8 2009

Galileo 240 2008 - 2011

Spacecraft Flight Units Launch

CharacteristicsDesign Description

The thruster valves are dual seat / dual coil solenoid

types. The solenoids are mechanically and electri-

cally decoupled from each other.

The thruster performance is identical for all valves.

The 1 N thruster uses the storable propellant

hydrazine N2O4. The propellant is decomposed

when passing the catalyst. It is designed for both,

long term steady state and pulse mode operation.

It operates in a wide pressure range and is thus an

ideal thruster for blow down propulsion systems.

Combustion chamber and nozzle are made of

Haynes 25. The thruster structure is designed also to

serve as a heat barrier for protecting valve and S/C

structure against unallowed temperatures. The

thruster is equipped with an internally redundant

catalyst bed heater and thermal insulation to

guarantee for optimum start up. In addition, the

thruster is qualified for multiple cold starts.

Characteristics Values

Thrust Nominal 1 N

Thrust Range 0.320 ... 1.1 N

Specific Impulse, Nominal 220 s

Pulse, Range 200 ... 223 s

Mass Flow, Nominal 0.44 g/s

Mass Flow, Range 0.142 ... 0.447 g/s

Inlet Pressure Range 5.5 ... 22 bar

Minimum Impulse Bit 0.01 ... 0.043 N

Nozzle Expansion Ratio (by area) 80

Mass, Thruster with valve 290 g

Propellant Hydrazine (N2H4), High-Purity Grade

Supplied Components

Catalyst Solvay, Belgium; KC 12 GA

Catalyst Bed Heater Cartridge Heater with redundant heating elements,

Power 6.4 W

Tayco Engineering, Cypress, U.S.A.

Valve, 16 V DC Dual Seat Dual Solenoid Valve, Power 6.5 W

MOOG, East Aurora, U.S.A.


MOOG, East Aurora, U.S.A.


A.E.R., France

Qualification

Total Impulse 112,000 kNs

Cycle Life 59,000 cycles

Propellant Throughput 52 kg

Single Burn Life 12 h

Accumulated Burn Life 50

No of Cold Starts bellow 100 C 10

Shock Loads, all axes 500 g for 0.5 ms

Structure Interface

Thruster Dimensions

Structure Cut out

Launch Vibration Loads

The thruster is qualified to withstand sinus and

random vibration at the shown levels. These loads

represent both, launcher loads and amplification by

the spacecraft. The loads are applied at the thruster

mounting flange.

Launch Vibration Loads

The thruster is qualified to withstand sinus and

random vibration at the shown levels. These loads

represent both, launcher loads and amplification by

the spacecraft. The loads are applied at the thruster

mounting flange.

Steady State Operation

Steady State PerformanceThrustThe thruster can be operated in blow down mode

over the entire inlet pressure range ( ratio of 4:1).

The decomposition behaviour is insensitive to

pressure variations, the thrust is a nearly linear

function of the feed pressure.

Steady State PerformanceSpecific ImpulseThe Specific Impulse is a measure for the thruster

efficiency. The higher the Isp, the better the

thruster. The efficiency of this thruster is worlwide

competitive.

Steady State Performance 400 ThrustersAcceptance hot firing data of 400 thrusters

demonstrate the performance reproducibility and

thus the constantly high quality of the thruster

production.

Pulse Mode PerformanceDuty Cycle QualificationThe thruster qualification program includes extensi-

ve pulse mode testing at numerous combinations

of valve ON- and valve OFF-times, ranging from

milliseconds to seconds, at various propellant inlet

pressures.

Pulse Mode PerformanceSpecific Impulse Thruster efficiency for pulse mode firing is naturally

lower than that of steady state operation, especially

the shorter the pulses. However, this thruster

achieves already 80% to 90% of its steady state

efficiency at 300 ms pulses.

Pulse Mode PerformanceImpulse BitIn analogy to the steady state thrust, the impulse bits

are a nearly linear function of the feed pressure.

Even at minimum feed pressure and pulse duration

the I-Bit deviation from thruster to thruster is only ±

12 %.

Pulse Operation

EADS Space TransportationPropulsion & EquipmentD 81663 Munich, GermanyPhone: +49-89-607 22148Fax: +49-89-607 [email protected]

www.space-propulsion.comwww.space.eads.netPr

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1N Hydrazine Thruster

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