Propulsion Systems

Fuel Formulation and Casting

Rocket Lab has the capability to formulate, handle and manufacture hybrid and solid fuel grains in its Auckland laboratories. The premises and staff are certified with the relevant dangerous goods/explosives certification required permitting handling, storage and use.

Rocket Lab currently formulates a number of hybrid propellants including “Impulse Green” which is offered to industry. Rocket Lab has a wide experience with Polyurethane and Polybutadiene based polymers including highly cross linked pre-polymers for the use in hybrid propulsion. Rocket Lab operates a full chemical laboratory for the development and analysis of hybrid rocket propellants.

Grains that have been cast range from a small 2” OD for fuel characterisation and combustion tests up to 8” in diameter for a second stage engine for a sounding rocket. Rocket Lab has the capability to cast the fuel grains up to 12.5” OD x 60”

Rocket Lab has also successfully cast grains with intricate details, such as the finical HTPB based hybrid fuel grain shown in the images below. These grains were cast for the second stage engine of the Ātea-2 sounding rocket.

Fuel Characterisation and Combustion Testing

Rocket Lab has the capability to conduct intensive development programs with fuel formulation, performance characterisation and selection through small scale combustion testing. Rocket Lab has developed a dedicated hybrid engine test cell that is used to characterise and test various fuels with a variety of oxidisers.

The test engine allows for quick change-outs of fuel grains with the engine fully instrumented.  Typically thrust, chamber pressures and temperatures are measured. The operator’s stand features live video feed and real-time display of data acquisition to monitor all test conditions are nominal while in operation.

Rocket Lab has conducted a detailed fuel selection program for its Ātea series of sounding rockets. Many different fuel formulations have been tested at various chamber pressures and Ox/Fuel ratios. The results of the tests were carefully analysed to gather data on regression rates, specific impulse and other performance characteristics.

Planning and Implementation of Propulsion System Testing Programs

Rocket Lab has significant experience and capabilities in conducting feasibility studies, design, development and testing programs for a variety of propulsion systems. These programs range from conducting ground-up conceptual design studies, intensive fuel formulation and combustion testing programs to full-scale ground test firings.

Rocket Lab has proven its experience in planning and implementation of testing programs through several projects, including:

• Tow motor emergency parachute extraction system for Martin Aircraft Company
• Ātea-2 second stage Nitrous Oxide/HTPB hybrid engine
• Ātea-1 booster hybrid engine program
• Development of high regression rate polymer wax composite fuel

Design and Manufacturing Capability

Rocket Lab has proven capability in designing, manufacturing and testing a variety of rocket engines ranging from 2-Newton thrust monopropellant thrusters to liquid bi-propellant designs up to 15,000lbf. Rocket Lab has significant experience in developing, manufacturing and testing ablatively cooled Nitrous Oxide hybrid engines through its Ātea sounding rocket programs. Some of the relevant projects are listed below.

• H₂O₂ hypergolic bi-propellant thruster – 10 lbf
• Solid fuel based tow rocket motor – 8 lbf
• Ātea-2 second stage Nitrous Oxide/HTPB hybrid engine – 450 lbf
• Ātea-1 booster hybrid engine program – 1550 lbf
• Bullet Project JP-5/H₂O₂ liquid bi-propellant engines – 4 x 15,000 lbf