Ad Astra team members who supported RF-PPU testing pose in front of the open vacuum chamber at the company’s Texas facility. Photo: Ad Astra Rocket Company

A new generation radio-frequency (RF) Power Processing Unit (PPU) for the VASIMR engine, built by Aethera Technologies for Ad Astra Rocket Company has completed a full-power test in vacuum at Ad Astra’s Texas facility near Houston on Jan. 20. The test involved operating the unit in hard vacuum and thermal steady- state at its full power rating of 120 kW. The PPU was also subjected to the magnetic field of the VASIMR engine to verify that there is no magnetic effect on the PPU performance. 

Short for Variable Specific Impulse Magnetoplasma Rocket, VASIMR uses plasma to create thrust. Plasma rockets, such as VASIMR, have an extremely low fuel consumption and a much higher performance compared to conventional chemical propulsion or other electric rockets. They provide economic and operational advantages in space logistics, including satellite deployment, re-boost, refurbishment and end-of-life disposal. 

This test completed one of the three remaining major technology milestones in Ad Astra’s NextSTEP Partnership Program contract with NASA for the maturation of the VASIMR engine. The VASIMR system is now positioned at technology readiness level 5, meaning that all critical engine components have been operated at full power in a relevant environment under vacuum. Ad Astra plans to complete the remaining two milestones involving long- duration 100 kW firings of the VX-200SS VASIMR test article this spring. 

“Watching the test was like a dream with all parameters maintaining very comfortable margins. What seemed like an easy test was a testimony to the quality of the teams that developed and tested this beautiful piece of equipment,” said Jared Squire, Senior VP Research.