Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, is showcasing disruptive space technologies at the 33rd annual Space Symposium, April 3-6.
Aerojet Rocketdyne technologies on display include:
3-D Printing: Aerojet Rocketdyne has been researching this innovative technology for more than a decade. To take advantage of the significant cost and schedule savings and novel design capabilities enabled by 3-D printing, the company is modernizing its RS-25 and RL10 engines, creating its Bantam family of engines and AR1 engine, and manufacturing new components for NASA’s Orion spacecraft with this technology.
In-Space Propulsion: Efficient propulsion is critical to a sustainable exploration or military space architecture. More than 100 satellites have used the company’s electric propulsion devices. Aerojet Rocketdyne is currently working with NASA on a portfolio of advanced electric thrusters, operating at power levels between 7 kW and 200 kW per thruster. Solar electric propulsion provides the potential to reduce lifecycle costs of space systems and increase maneuverability of satellites. In addition to solar electric propulsion, the company is also working on advanced chemical systems and nuclear thermal propulsion, optimizing them to meet customers’ mission requirements.
In 2015, NASA awarded $6.5 million over the next three years to Aerojet Rocketdyne for the development of the propulsion system, dubbed the XR-100. Gallimore’s thruster, the X3, is central to this system, and his team at U-M will receive $1 million of the award for work on the thruster.
The XR-100 is up against two competing designs. All three of them rely on ejecting plasma—an energetic state of matter in which electrons and charged atoms called ions coexist—but the back of the thruster.
The X3 has a bit of a head start. For thrusters of its design power, 200 kilowatts, it is relatively small and light. And the core technology—the Hall thruster—is already in use for maneuvering satellites in orbit around Earth.
“For comparison, the most powerful Hall thruster in orbit right now is 4.5 kilowatts,” Gallimore said.
Electric propulsion has seen rapid adoption in recent years for commercial, scientific, and exploratory space missions. The X3 is a three channel nested channel Hall thruster, designed to push the boundaries of high power electric propulsion for cargo transfer to Mars and large military assets. It has been operated at thermal steady state up to 30 kW of power. Thrust measurements were made on an inverted pendulum thrust stand, indicating over 2000 s specific impulse and 65 mN/kW thrust to power ratio. Detailed plume measurements were made with Faraday and Langmuir probes. The multiple concentric channels provide better performance than the sum of the individual channel operations due to superior propellant utilization from its compact design. Using a high speed camera, the breathing and spoke mode instabilities were captured in all three channels. Spoke and breathing instabilities couple between the channels, indicating that complex plasma and neutral interactions are at play. Electron transport, both cross field and in the cathode plume, are well suited to be explored in a thruster of this size.
With all 3 channels running at 30 kW total discharge power, the anode specific impulse was 1840 s, anode efficiency was 45.0%, and thrust was 1518 mN. Anode specific impulse ranged from 1200 s to 2300 s across operating conditions and anode efficiency ranged from 21% to 67%.
An X3 thruster that AERO Professor Alec Gallimore’s team has been working on in conjunction with NASA
Reusability: Aerojet Rocketdyne has a long and successful track record of developing operational, reusable engines, such as the RS-25 that flew 135 times on the space shuttle. This heritage has yielded a proven-calibrated design system capable of generating robust, highly reusable engines and propulsion systems for future launch and space missions.
“Our disruptive technologies are changing the economics of space launch without sacrificing performance or mission success,” said Aerojet Rocketdyne CEO and President Eileen Drake.