Details of a candidate reusable launch vehicle (RLV) rocket engine design for the European Space Agency's next generation launcher (NGL) are emerging.
The agency is funding research that could enable a full-flow, staged combustion, liquid oxygen- (LOX), liquid hydrogen- (LH2) or methane-fuelled 449,000lb-vacuum thrust (2000kN) engine that would provide up to 448s specific impulse and be reused a maximum of 25 times.
It would use a single preburner and either a single- or dual-shaft turbopump that would use clutch thrust bearings. Its total system mass goal is less than 3,200kg (7,040lb).
The engine specification has emerged from the ESA's future launcher preparatory programme (FLPP). FLPP's goal is to demonstrate relevant engine subsystems with technological readiness levels (TRL) of five by 2010. The TRL-5 rating is given to technology successfully demonstrated in a relevant environment.
FLPP's RLV and expendable launch vehicle (ELV) work will inform the member states' fourth quarter 2008 decision on NGL development.
The RLV NGL engine would power a two stage to orbit (TSTO) or reusable first stage (RFS) NGL to place up to 7,500kg (16,500lb) into a geostationary transfer orbit (GTO) or up to 5,000kg into a 700km (434 miles) Sun synchronous orbit (SSO).
This ESA market forecast-driven mission requirement is below the Arianespace Ariane 5's performance capabilities. The in-service Ariane 5 ECA variant can place 9,600kg into GTO and its generic version can put 9,500kg into an SSO at 800km.
If approved by ESA's member states the NGL, whether it is reusable or expendable, is envisaged to be operational in 2020-2025, replacing the Ariane 5.
FLPP's RLV engine work emphasises staged combustion and reusability for the engine's igniters, valves, turbopumps, long-life combustion chambers, preburners, advanced nozzle extensions, turbines and health monitoring systems.
NASA's Space Shuttle main engine is a staged combustion system, however ESA has no such operational system.
Its member states' relevant past research includes an oxygen-rich preburner, a single-shaft turbopump axially integrated with its preburner and main chamber, a LOX regeneratively cooled main chamber and copper chamber liner with milled cooling channels.
EADS Astrium, Snecma and Avio are all involved in the FLPP work.
For a staged combustor "pathfinder" test rig Snecma has provided a preburner chamber with three injector head variants and Astrium provided the main chamber that had three hot gas injector variants.
Source: FlightGlobal.com
