NASA and Aerojet Rocketdyne begin testing the most powerful electric motors ever

NASA and Aerojet Rocketdyne have begun years-long testing of the world’s most powerful solar-electric propulsion technology, which experts say will revolutionize the way space propulsion works. This is reported by a press release from the space agency.

For a long time, space exploration relied on chemical propulsion, which created millions of tons of thrust and made it possible to build ever larger and more powerful long-range rockets. But it’s not the most efficient way to move around in space.

Chemical propulsion requires spacecraft to carry large amounts of propellant, especially if they are to return to Earth. At the same time, electric propulsion can significantly reduce fuel consumption and increase flight speed, making it critical for future missions.

What is solar-electric traction?

In an electrical propulsion system, electricity is used to ionize inert gases such as xenon or krypton. A magnetic or electrostatic field then accelerates these ions and pushes them out of the motor, creating a high speed. It might not look spectacular without the fiery effects we’re used to seeing in rocket engines, but it’s still a stunning sight.

Interestingly, the electricity needed to ionize gases can be obtained from sunlight, which is abundant throughout the solar system.

Electric motors also allow spacecraft to change their speed and trajectory during a mission.

NASA has already experimented with PET on its Dawn mission, but is now preparing to demonstrate the most powerful version, which will be installed on the power and propulsion element (PPE) on Gateway, its station that will orbit around the moon.

Gateway is a 60kW class spacecraft, of which 50kW will be devoted to propulsion. Aerojet Rocketdyne has developed an electric propulsion system called the Advanced Electric Propulsion System (AEPS).

The AEPS power is 12kW, twice that of the most advanced electric propulsion system. But before becoming part of the PPE on the Gateway, the AEPS must be tested for compliance.

To do this, NASA and Aerojet have begun a year-long test of one of the verification samples, which is identical to the engines that will fly on the Gateway in 2025. After confirming that the engine is assembled correctly, engineers subject it to extreme shock, vibration and temperatures, simulating conditions during the launch and flight of the Artemis mission.

Another sample for verification will be ready in 2024 and will be tested simulating the maneuvers of lifting into orbit and transfer to the lunar orbit. All testing is done in huge vacuum chambers at NASA’s Glenn Center.

“This testing campaign is a big deal,” said Rohit Shastri, AEPS chief engineer. “This is sort of the last step before we test the engines that will fly on the Gateway.”

The comprehensive test will include 23,000 engine hours over four years. The engines that will be installed on the PPE Gateway will actually be running before the end of wear testing is completed.

“For NASA missions, launch dates are very important,” Clayton Cashele, AEPS project manager at NASA’s Glenn Center, said in a press release. “In this case, NASA is trying to speed up the process, and we are doing it wisely. We will complete several thousand hours of wear testing to prove successful performance before PPE is launched. We will then complete the remaining 15,000 hours or so to fully qualify AEPS for future customers.”