Aerojet Rocketdyne demonstrates electric propulsion capabilities for future deep space missions
An early systems integration test was performed by Aerojet Rocketdyne for NASA’s Advanced Electric Propulsion System (AEPS) program, which includes technology that could be used on NASA’s proposed lunar-orbiting outpost in the early 2020s, the company said.
Aerojet Rocketdyne is under contract with NASA to develop and qualify a 13-kilowatt Hall thruster string for the U.S. space agency. According to the company in an Aug. 28, 2018, news release, the recent test focused on the power elements of the AEPS Hall thruster string, in particular the discharge supply unit and the power processing unit, to prove the system’s ability to convert power at a high efficiency level and produce minimal waste heat.
Hall thrusters, a type of ion thruster, trap electrons in a magnetic field and use them to ionize the onboard propellant (typically xenon), accelerating them outward to produce thrust, according to NASA. Overall, these engines use 10 times less propellant than traditional chemical rockets.
“By staying on the cutting edge of propulsion technology, we have positioned ourselves for a major role not only in getting back to the Moon, but also in any future initiative to send people to Mars,” said Eileen Drake, Aerojet Rocketdyne CEO and president, in a company statement. “AEPS is the vanguard for the next generation of deep space exploration and we’re thrilled to be at the mast.”
Drake said the AEPS discharge supply unit performed “exceptionally,” and yielded “significant conversion efficiency improvements” for demanding deep space missions in the future.
“These results are a testament to the Aerojet Rocketdyne team’s focus and dedication to advancing the state of the art in this critical in-space technology area,” Drake said.
According to the company, the early integrated systems test combined a breadboard AEPS power processing unit and discharge supply unit with a NASA development thruster. The test took place in a thermal vacuum chamber at the U.S. space agency’s Glenn Research Center in Cleveland, Ohio.
The next step will be to finalize and verify the design before the critical design review, which would clear the system for production, Aerojet Rocketdyne said.
One immediate potential use of Aerojet Rocketdyne’s AEPS thruster would be on the Power and Propulsion Element of NASA’s proposed lunar Gateway, an outpost in a lunar orbit that would be human tended for 30 to 90 days at a time.
The most recent plans for the lunar Gateway call for an industry-designed Power and Propulsion Element to be launched in 2022 atop a commercial launch vehicle. It would provide the outpost power, in-space transportation using advanced solar electric propulsion and initial lunar communications.
Within a year, two more modules would be attached to the Gateway to provide an early operational capability, according to NASA. These would be the European System Providing Refueling Infrastructure and Telecommunications (ESPRIT), provided by the European Space Agency, and a U.S. Utilization Module.
ESPRIT would provide a refueling capability for the Power and Propulsion Element, a science airlock as well as additional lunar communications. The U.S. Utilization Module would provide initial habitation volume and logistics for up to 15 days, according to NASA. Both are expected to be launched atop the Space Launch System. It is unclear if they would fly together or separately.
The early operational capability would allow the outpost to be visited by human crews as early as 2024 via NASA’s Orion spacecraft. Eventually other elements would be added, including both U.S. and international partner habitats, an airlock and a robotic arm. The Gateway would also be regularly serviced by logistics spacecraft.
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity.