VASIMR Technology Development wins Two NASA Contracts
NASA has awarded two contracts to Ad Astra Rocket Company to continue the maturation of the VASIMR rocket technology. The VASIMR engine is a high-power electric propulsion system under development by Ad Astra.
“It has been a long journey from the early proof-of-concept years to a technology near the threshold of space testing."
Dr. Franklin Chang Díaz, Ad Astra
The two contracts address Ad Astra’s two new design innovations to the high-power radio frequency (RF) power subsystem of the engine. These components efficiently deliver the electrical energy to the VASIMR plasma in the form of electromagnetic waves. The two innovations involve both materials and manufacturing advances that greatly increase the ability of these components to manage the high temperatures of the engine core.
In the first contract, awarded in late June of this year, Ad Astra will take an improved 2nd-stage RF coupler from the conceptualization stage, completed under a 2022 NASA contract, to full- scale manufacturing. After manufacturing, the new RF coupler will be integrated and tested in the VX- 200SS VASIMR prototype.
VASMIR Contract Details
Responsible for delivering (coupling) the energy to the plasma as electromagnetic waves, the RF coupler is a critical component of the engine that lies deep inside the rocket core. The component must be rugged, lightweight, and be able to operate in vacuum at temperatures of several hundred oC while sustaining operating voltages of several thousand volts without arcing. In the second contract, awarded this month, Ad Astra will test an innovative design of the high- current segment of the RF transmission line that delivers the power to the 2nd-stage RF Coupler. Like the coupler itself, the high-current segment of the transmission line also operates in the harsh environment of the rocket core. The design innovation featured in this component improves its thermal management, increasing overall efficiency and reducing weight.
The VASIMR (Variable Specific Impulse Magnetoplasma Rocket) engine has two of these couplers, one for each of the two stages. However, the focus of these two contracts will be on the second stage, the so-called, “Heater” stage, which delivers the largest fraction of the power to the plasma. Nonetheless, these design improvements will be relevant to the engine’s 1st-stage, the “Ionizer” stage as well, systemically enhancing the operational envelope of the entire engine.
With these design improvements, Ad Astra looks to increase the thermal steady-state power of the VASIMR VX200SS prototype from its record- setting 80 kW to greater than 100 kW, at Technology Readiness Level (TRL) 5, a goal expected for mid-2024. Achieving this goal will set the stage for transitioning the VASIMR to TRL-6, an engine capable of being field tested in space.
“We are proud to be working with NASA in the final steps of our VASIMR technology maturation program,” said Dr. Franklin Chang Díaz, Ad Astra’s Chairman and CEO. “It has been a long journey from the early proof-of-concept years to a technology near the threshold of space testing. We look forward to jointly advancing to flight readiness,” he added.
(Source: Ad Astra Rocket Company news release. Image from Ad Astra Kickstarter campaign)