NASA engineers have tested a 3D printed rocket engine turbo pump with liquid methane — an ideal propellant for engines needed to power many types of spacecraft for NASA’s journey to Mars and other deep-space missions.
A turbo pump is complex because it has turbines that spin fast to drive the pump which supplies fuel to the engine.
“This is one of the most complex rocket parts NASA has ever tested with liquid methane — a propellant that would work well for fuelling Mars landers and other spacecraft,” said Mary Beth Koelbl, manager of the propulsions systems department at NASA.
“Additive manufacturing or 3D printing made it possible to quickly design, build and test two turbo pumps with identical designs that worked well with both liquid methane and liquid hydrogen propellant,” he said in a statement.
During the full power test, the turbines generated 600 horsepower and the fuel pump, got its “heartbeat” racing at more than 36,000 revolutions per minute.
This delivered 600 gallons of semi-cryogenic liquid methane per minute — enough to fuel an engine producing over 22,500 pounds of thrust. Three other tests were completed at lower power levels.
“Methane propulsion and additive manufacturing are key technologies for the future of exploration including NASA’s journey to Mars,” added Graham Nelson, a Marshall propulsion engineer.
“We are excited to complete testing that advances both these technologies at the same time and improves the capabilities of future missions,” he noted.
Liquid methane is cooled to -159 degrees Celsius whereas liquid hydrogen is cooled to -240 degrees Celsius.
The higher temperature of liquid methane means it boils off more slowly and thus is easier to store for longer periods – a benefit for Mars missions.
Also, technologies exist today to make it possible to manufacture methane rocket fuel from carbon dioxide, which is plentiful in the Red Planet’s atmosphere.
“By demonstrating the same turbo pump can work with different fuels, we’ve shown that a common design would work for either engines fuelled by methane or hydrogen,” said Marty Calvert, the Marshall engineer who designed the turbo pump.
“Additive manufacturing allowed us to build the turbo pump with 45 percent fewer parts,” added Nick Case the Marshall propulsion engineer who led the testing.
The next step is to test the liquid methane turbo pump with other 3D printed engine components in a similar configuration to the liquid hydrogen tests completed last year.