The LEROS MHT-1N
European High Reliability 1N hydrazine Thruster
Design and development of a European Advanced Monopropellant 1N thruster called the MHT-1N that offers greater endurance/functional life capability than all existing 'flight-proven' heritage designs.
The challenge was to design, manufacture and prove through extensive testing a European 1 Newton hydrazine thruster that would out-perform existing 1N offerings in terms of long mission life (90kg throughput of hydrazine vs ‘standard’ 50kg capability thrusters) whilst offering excellent performance including a minimum 226 seconds Isp at 24 bar inlet pressure. In parallel with this advanced thruster development, the High Altitude Test Facility at Westcott UK has been taken to World Class capability in order to provide high accuracy measured thrust for every MHT-1N produced.
The MHT-1N thruster is manufactured at Westcott and has 80% European geo-return (67% UK, 10% France, 3% Germany). Only the FCV is from the USA.
Its catalyst bed heater gets to pre-heat in under 8 minutes with 1 element and approximately 3 minutes using both elements.
Unique ‘Quick Start’ procedure for warming the catalyst bed to pre-heat temperature without the use of the heater. This eliminates the need for traditional Cold Starts that are proven to damage standard monoprop thrusters. This ‘Quick Start’ technique has been approved by ESA.
It can be supplied with either a dual-redundancy k-type thermocouple or a PRT-500 for temperature sensing.
The MHT-1N will be qualified to a higher hydrazine throughput than any other available thruster – 90kg vs typically 50kg – which makes is ideally suited to meeting EOL de-orbit requirements of longer mission life.
It will fly in June 2017 and has already been qualified (to 44kg throughput in August 2016) for a UK Satellite prime.
Westcott has developed its own catalyst packing methodology and all major steps are quantified at key stages to ensure high repeatability in the cat packing process.
It has innovative in-life catalyst bed conditioning and unique injector design for enhanced cat bed life and hence better EOL performance compared to standard designs.
Minimum Isp of 226 secs at 24 bar inlet pressure.
The MHT-1N thruster incorporates an innovative Thrust Chamber Assembly with highly optimised injector and catalyst retention designs that have been proven over a 5 year development programme.
Phase 2 commenced January 2017 which will take the MHT-1N thruster to full ESA qualification with a 90kg throughput of hydrazine targeted including 450,000 pulses and up 10 hour steady state burns.
Phase 1 took the thruster from concept through Development Models, Engineering Model and qualification to 44kg hydrazine throughput – primarily steady state burns. Thruster demonstrated excellent performance throughout this first qualification. Currently another Qualification Model thruster is being prepared in order to complete a 90kg higher throughput ESA qualification as described above.