Post on 29-Nov-2014
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
Cosmo-SkyMed 2 6 2006
Radarsat-2 6 2006
Galileo GSTB-V2 8 2006
Cosmo-SkyMed 3 6 2007
Cosmo-SkyMed 4 6 2007
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.
Valve, 28 V DC Dual Seat Dual Solenoid Valve, Power 9.5 W
MOOG, East Aurora, U.S.A.
Valve, 28 V DC Dual Seat Dual Solenoid Valve, Power 9.5 W
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 85148Henning.vonBassewitz@space.eads.net
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