1n thruster

1 N MoNo-ProPellaNt thrusterReliable contRol of small and midsize spacecRaft

1 N

all the space you need

1 n mono-propellant thruster

Heritage

Astrium is engaged in the mono-propellant hydra-zine 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.

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 Astrium or foreign supplier depending on customer´s request. The thruster is an All European Product when euipped with the Astrium valve.


1 N Thruster in Space

More than 500 units of the thruster´s first and second generation operate successfully in space to date, and further will follow. (* Spacecraft will be launched in the near future)

Spacecraft Launch

GLOBALSTAR 1998

Jason-1 (Proteus) 2001

Rocsat 2004

Calipso (Proteus) 2006

Corot (Proteus) 2006

CosmoSkymed-1 2007

CosmoSkymed-2 2007

Radarsat 2007

Terra-SAR 2007

CosmoSkymed-3 2008

GSTB-B 2008

Jason-2 (Proteus) 2008

Theos 2008

Herschel/Planck 2009

Spirale 1 (Myriade) 2009

Spacecraft Launch

Spirale 2 (Myriade) 2009

SMOS (Proteus) 2009

TANDEM-X 2010

Alsat 2A (Myriade) 2010

CosmoSkymed-4 2010

CosmoSkymed-4 2010

Elisa-1 (Myriade) 2011


Elisa-3 Myriade) 2011


Pleiades HR1 2011

SSOT (Myriade) 2011

Jason-3 2013

Alsat 2B (Myriade) *AstroTerra 1 *

Spacecraft Launch

AstroTerra 2 *CSO-1 *CSO-2 *CSO-3 *KRS *Pleiades HR2 *Sentinel-2 A *Sentinel-2 B *Sentinel-5P *SEOSAR *SEOSAT *Taranis (Myriade) *Vietnam-1 (Myriade) *Vietnam-1 (Myriade) *


Design 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 pro-pellant 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 improper high temperatures. The thruster is equipped with an internally redundant catalyst bed heater and with thermal insulation to guarantee for optimum start up. In addition, the thruster is qualified for multiple cold starts.

1 n

Thruster Model CHT-1N


Characteristics

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

SuppLiedcomponentS

Catalyst Foreign Supplier

Catalyst Bed Heater Cartridge Heater with redundant heating elements, Power 6.4 W

Foreign Supplier

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

Valve, 28 V DC Dual Seat Dual Solenoid Valve, Power 9.5 W, foreign supplier

Valve, 28 V DC Dual Seat Dual Solenoid Valve, Power 9.5 W, Astrium

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


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.


Structure interface

thruSterdimenSionS

Structurecutout

puLSemodeperformancedutycycLeQuaLification

The thruster qualification program includes extensive pulse mode testing at numerous combinations of valve ON- and valve OFF-times, ranging from milliseconds to seconds, at various propellant inlet pressures.

puLSemodeperformanceSpecificimpuLSe

Thruster efficiency for pulse mode firing is naturally lower than that of steady state operation, espe-cially the shorter the pulses. However, this thruster achieves already 80% to 90% of its steady state efficiency at 300 ms pulses.

puLSemodeperformanceimpuLSeBit

In 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 %.


Puls Operation

SteadyStateperformancethruSt

The 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.

SteadyStateperformanceSpecificimpuLSe

The 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.

SteadyStateperformance400thruSterS

Acceptance hot firing data of 400 thrusters demonstrate the performance reproducibility and thus the constantly high quality of the thruster production.


Steady State Operation

astriuMProPulsioN & equiPMeNtD 81663 Munich, GermanyPhone: +49 (0) 89 607 32480 · Fax: +49 (0) 89 607 [email protected] · www.astrium.eads.net

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1n thruster

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