Successful tests could lead to further advances in propulsion technology

NASA’s Second Generation Reusable Launch Vehicle Program is said to be making advances in propulsion technology after a third and final engine hot-fire designed to test electro-mechanical actuators.

NASA’s Second Generation Reusable Launch Vehicle Program – also known as the Space Launch Initiative – is said to be making advances in propulsion technology with this third and final successful engine hot-fire designed to test electro-mechanical actuators.

The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed at NASA’s Stennis Space Centre, where the engines were fired for the planned 90-seconds and reached a planned maximum power of 85 percent.

The test was originally slated to attain full power during 100-seconds of testing.

Prior to the test, engineers determined the necessary results could be achieved at reduced duration and power. Based on this determination, both planned duration and planned power were reduced.

Two shorter hot-fires of the aerospike engines were performed in July in preparation for the final test firing.

Electro-mechanical actuators electronically regulate the amount of propellant (fuel and oxidiser) flow in the engine.

The new technology is a potential alternative and improvement to the older pneumatic and hydraulic-fluid systems currently used by the aerospace industry to drive and control critical rocket engine valves.

‘Firing allows us to see how the integrated system handles the extreme cold of cryogenic propellants, the stress loads of the propellants pushing through the valves, and the dynamic response to commanded flow rate changes,’ said Dr. Donald Chenevert, electro-mechanical actuator project manager at the Stennis Centre

‘Additionally, we have many other unique conditions such as shock and vibration loads not found in a lab, so we capture more realistic data about the true performance of the actuators.’

Engineers are performing engine post-test inspections, and early indications are that all test objectives have been met, added Chenevert.

The final data is to be fed directly into the engine systems being considered for a second-generation, reusable launch vehicle, said Garry Lyles, Propulsion Projects Office manager of the Second Generation Reusable Launch Vehicle Program at the Marshall Centre.

‘Propulsion is one of the highest and most critical technology areas that we are exploring,’ said Dennis Smith, manager of the Second Generation Reusable Launch Vehicle Program Office at the Marshall Centre. ‘Our goal also is to find, improve or develop technologies such as airframes, avionics, health management systems and ground operations.’

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